Resin composition and resin molded article

Abstract

A resin composition includes a polycarbonate-based resin and a polyethylene terephthalate resin, and the resin composition has a resin phase-separated structure including a continuous phase containing the polycarbonate-based resin and a dispersed phase containing the polyethylene terephthalate resin, in which a number average diameter in a longitudinal direction of the dispersed phase is 1.5 μm or less, a number average diameter in a lateral direction of the dispersed phase is 0.8 μm or less, and an aspect ratio of the number average diameter in the longitudinal direction to the number average diameter in the lateral direction is 2.5 or less.

Claims

1. A resin composition, comprising: a resin component comprising: a polycarbonate-based resin; and a polyethylene terephthalate resin; an organic phosphorus flame retardant; and a flame retardant anti-dripping agent, the resin composition having: a resin phase-separated structure including a continuous phase containing the polycarbonate-based resin and a dispersed phase containing the polyethylene terephthalate resin, wherein: a number average diameter in a longitudinal direction of the dispersed phase is 1.5 μm or less, a number average diameter in a lateral direction of the dispersed phase is 0.8 μm or less, an aspect ratio of the number average diameter in the longitudinal direction to the number average diameter in the lateral direction is 2.5 or less, and a content of the flame retardant anti-dripping agent is 0.3 part by mass or more and 0.8 part by mass or less based on 100 parts by mass of the resin component.

2. The resin composition according to claim 1, wherein the number average diameter in the longitudinal direction of the dispersed phase is 0.5 μm or more and 1.3 μm or less.

3. The resin composition according to claim 1, wherein the number average diameter in the lateral direction of the dispersed phase is 0.1 μm or more and 0.6 μm or less.

4. The resin composition according to claim 1, wherein the organic phosphorus flame retardant contains a condensed phosphate.

5. The resin composition according to claim 2, wherein the organic phosphorus flame retardant contains a condensed phosphate.

6. The resin composition according to claim 3, wherein the organic phosphorus flame retardant contains a condensed phosphate.

7. The resin composition according to claim 1, wherein the flame retardant anti-dripping agent contains a fluorine-containing resin.

8. The resin composition according to claim 2, wherein the flame retardant anti-dripping agent contains a fluorine-containing resin.

9. The resin composition according to claim 3, wherein the flame retardant anti-dripping agent contains a fluorine-containing resin.

10. The resin composition according to claim 7, wherein the fluorine-containing resin contains polytetrafluoroethylene (PTFE).

11. The resin composition according to claim 1, wherein a content of the organic phosphorus flame retardant is 1 part by mass or more and 25 parts by mass or less based on 100 parts by mass of the resin component.

12. The resin composition according to claim 1, wherein a content of the polycarbonate-based resin is 40 parts by mass or more and 90 parts by mass or less based on 100 parts by mass of the resin component.

13. The resin composition according to claim 1, wherein a content of the polyethylene terephthalate resin is 10 parts by mass or more and 40 parts by mass or less based on 100 parts by mass of the resin component.

14. The resin composition according to claim 1, wherein when a value of ½ of the number average diameter R.sub.LONG in the longitudinal direction of the dispersed phase is substituted for r.sub.i in the following Equation (A), a value of a specific surface area A represented by the following Equation (A) is 2.0 or more, and when a value of ½ of the number average diameter R.sub.SHORT in the lateral direction of the dispersed phase is substituted for r.sub.i in the following Equation (A), the value of the specific surface area A represented by the following Equation (A) is 7.0 or more, $\begin{array}{cc}A=\frac{\underset{i}{.Math.}N\times 4\pi r_i^2}{\underset{i}{.Math.}\frac{N\times 4\pi r_i^3}{3}}& \left(A\right)\end{array}$ [in the Equation (A), A represents the specific surface area of the dispersed phase, N represents the number of the dispersed phase in an observation visual field, and r.sub.i represents a radius of an i-th dispersed phase].

15. A resin molded article comprising: the resin composition according to claim 1.

16. The resin molded article according to claim 13, which is an injection molded article.

17. The resin composition according to claim 1, wherein the resin component further comprises a glycidyl group-containing polyethylene-based copolymer.

18. The resin composition according to claim 1, wherein the resin component further comprises a methyl methacrylate-butadiene-styrene copolymer.

19. The resin composition according to claim 1, wherein the resin component consists of the polycarbonate-based resin and the polyethylene terephthalate resin.

Description

EXAMPLES

(1) Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to the following Examples. Materials, used amounts, ratios, processing procedures, and the like shown in the following Examples may be appropriately changed without departing from the spirit of the present disclosure.

(2) The term “part” refers to “part by mass” unless otherwise specified.

Preparation of Material

(3) The following materials are prepared.

Polycarbonate-Based Resin

(4) The polycarbonate-based resin used in Examples and Comparative Examples is a recycled PC resin derived from a beverage bottle.

Polyethylene Terephthalate Resin

(5) The polyethylene terephthalate resin used in Examples or Comparative Examples is a recycled PET resin derived from a beverage bottle made of polyethylene terephthalate.

Other Resins

Glycidyl Group-Containing Polyethylene-Based Copolymer

(6) AX8900, manufactured by ARKEMA

(7) Glycidyl methacrylate/ethylene/methyl acrylate copolymer (composition ratio in mass %: 8/68/24), glass phase transition point (Tg): −33° C.

Methyl Methacrylate-Butadiene-Styrene Copolymer (MBS Copolymer)

(8) C-223A, manufactured by Mitsubishi Chemical Corporation [0085]

Organic Phosphorus Flame Retardant

Aromatic Condensed Phosphate

(9) CR-741, manufactured by Daihachi Chemical Industry Co., Ltd., phosphorus content: 9%

Ammonium Polyphosphate

(10) AP422, manufactured by Clariant International Ltd.

Flame Retardant Anti-Dripping Agent

Flame Retardant Anti-Dripping Agent 1

(11) FX500H, manufactured by Daikin Industries, Ltd., polytetrafluoroethylene content: 100%

Antioxidant

Antioxidant 1

(12) Irganox 1076 manufactured by BASF Corporation, Phenol based antioxidant

(13) Table 1 shows the weight average molecular weight (Mw), the number average molecular weight (Mn), Mw/Mn, and the concentration of terminal hydroxy groups of the polycarbonate-based resin, which are obtained by the measurement methods described above.

(14) TABLE-US-00001 TABLE 1 Concentration of Mw/ terminal hydroxy Resin Mw Mn Mn groups [μeq/g] Polycarbonate-based 58500 19400 3.02 12 resin

Preparation of Resin Composition

Examples 1 to 8 and Comparative Examples 1 to 3

(15) The polycarbonate-based resin, the polyethylene terephthalate resin, the flame retardant anti-dripping agent, the organic phosphorus flame retardant, and the antioxidant as needed having the types and amounts shown in Table 2 are mixed in a tumbler. Thereafter, in a twin-screw extruder with a vent (TEX-30a manufactured by the Japan Steel Works, LTD., L/D=49), the barrel (cylinder) temperature is set to the temperature (kneading temperature) shown in Table 2, and the die temperature is set to the temperature (die temperature) shown in Table 2. The screw having three kneading zones is used. Then, the resin composition of each example is melt-kneaded under the conditions of a kneading specific energy (ESP value, work amount added per unit weight) shown in Table 2, a screw rotation speed of 240 rpm, a vent suction degree of 100 MPa, and a discharge rate of 10 kg/h.

(16) The barrel of the twin-screw extruder with a vent is divided into 14 segments in the longitudinal direction (direction that raw material is extruded). The amount of the organic phosphorus flame retardant shown in Table 2 is added to the melt-kneading system from a charging port provided on the eighth segment of the barrel. Subsequently, the resin discharged from the twin-screw extruder is cut into pellet shapes.

Preparation of Resin Molded Article

(17) The obtained pellet-shaped resin composition is dried at 90° C. for 4 hours using a hot air dryer, and is then injection-molded by using an injection molding machine (“NEX500”, manufactured by Toshiba Machine Co., Ltd.) at a cylinder temperature of 260° C. and a mold temperature of 60° C., to obtain the resin molded article (evaluation test piece) of each example.

(18) A center portion in the cross-sectional direction of the resin molded article of each example is cut into 1 mm square. The polyethylene terephthalate resin in the resin molded article is dyed with ruthenium tetroxide. Thereafter, the resin molded article is cut by using an ultramicrotome at −196° C. to make an ultrathin section of 0.1 μm or less (about 80 nm), and the ultrathin section is observed with a transmission electron microscope (JEM-2100 manufactured by JEOL Ltd.) under a magnification of 35,000 times. As a result, it is confirmed that each resin molded article forms a phase-separated structure (sea-island structure) including a continuous phase containing a polycarbonate-based resin and a dispersed phase containing a polyethylene terephthalate resin.

(19) Table 2 shows the number average diameter in the longitudinal direction of the dispersed phase, the number average diameter in the lateral direction of the dispersed phase, the aspect ratio, and the value of the specific surface area A in the Equation (A), which are obtained by the above-described measurement methods. The value of the specific surface area A in the Equation (A) is obtained, based on the image obtained by the transmission electron microscope, by using the image analysis software “Image J” manufactured by National Institutes of Health of USA.

Evaluation and Test

(20) The following evaluations and tests are performed on the resin composition of each example. Table 2 shows each result.

Evaluation on Measurement Stability

(21) In the preparation of the resin molded article using the resin composition of each example, a flat plate (300 mm×200 mm, thickness 1.8 mm) is injection-molded and the measurement time is measured. Molding is performed for 30 shots, and the average measurement time (arithmetic mean value), the standard deviation, and the variation (calculated by dividing (standard deviation×3) by average measurement time) are obtained.

Tensile Strength and Tensile Elongation at Break

(22) An injection molded article as a JIS No. 1 test piece (thickness: 4 mm) is obtained by injection molding from the resin composition of each example. The tensile strength and tensile elongation at break of the obtained injection molded article are measured according to JIS K-7113.

(23) The larger the value of tensile strength, the better the tensile strength.

(24) The larger the value of tensile elongation at break, the better the tensile elongation at break.

Charpy Impact Resistance Strength

(25) For an ISO multipurpose dumbbell test piece of the resin molded article of each example that is subjected to a notch processing, the Charpy impact resistance strength (unit: kJ/m.sup.2) is measured in the MD direction by a digital impact tester (DG-5 manufactured by Toyo Seiki Co., Ltd.) according to ISO-179. The measurement conditions are a lifting angle of 150 degrees, a hammer used of 2.0 J, and the number of measurements n=10.

(26) The larger the value of the Charpy impact resistance strength, the better the impact resistance.

(27) TABLE-US-00002 TABLE 2 Compar- Compar- Compar- ative ative ative Example Example Example Example Example Example Example Example Example Example Example Composition 1 2 1 2 3 3 4 5 6 7 8 Resin Polycarbonate-based resin 63 63 63 63 63 63 63 63 63 91 59 compo- Polyethylene 37 37 37 37 37 37 37 37 37 9 41 sition terephthalate resin Glycidyl group- 5 0 5 5 0 5 0 0 0 0 0 containing polyethylene- based copolymer MBS copolymer 0 5 0 0 0 0 0 0 0 0 0 Organic Aromatic 15 15 15 15 0 0 15 26 15 15 15 phosphorus condensed flame phosphate retardant Ammonium 0 0 0 0 0 15 0 0 0 0 0 poly- phosphate Flame PTFE 0.5 0.5 0.5 0.5 0 0.5 0.5 0.5 0.9 0.5 0.5 retardant anti-dripping agent Antioxidant 0.2 0.2 0.2 0.2 0 0.2 0.2 0.2 0.2 0.2 0.2 Content Content (part by mass) 14 14 14 14 0 14 15 26 15 15 15 of of organic phosphorus material flame retardant based Content (part by mass) 0.5 0.5 0.5 0.5 0.0 0.5 0.5 0.5 0.9 0.5 0.5 on 100 of flame retardant anti- parts by dripping agent mass of Content (part by mass) 60 60 60 60 63 60 63 63 63 91 59 resin of polycarbonate- compo- based resin nents Content (part by mass) 35 35 35 35 37 35 37 37 37 9 41 of polyethylene terephthalate resin Molding Kneading temperature 250 250 260 270 250 250 250 250 250 250 250 condition Die temperature 250 250 260 270 250 250 250 250 250 250 250 EPS (kWh/kg) 0.16 0.15 0.12 0.11 0.26 0.21 0.15 0.07 0.14 0.25 0.14 Resin Number average 0.90 1.40 1.62 1.92 2.96 1.45 1.40 0.88 1.38 1.50 1.48 phase- diameter (μm) in separated longitudinal direction structure Number average diameter 0.41 0.61 0.53 0.57 0.86 0.59 0.60 0.38 0.56 0.61 0.61 (μm) in lateral direction Aspect ratio 2.2 2.3 3.0 3.4 3.4 2.5 2.3 2.3 2.5 2.5 2.4 Specific surface area A 2.70 2.24 0.77 0.63 0.52 2.03 2.23 2.68 0.83 0.61 0.81 in longitudinal direction Specific surface area A 7.85 7.12 5.69 4.87 3.44 7.01 7.13 7.75 5.88 4.52 5.96 in lateral direction Measure- Average measurement 10.81 11.02 13.68 14.89 25.41 11.5 11.01 12.42 13.26 13.34 13.51 ment time (s) stability Standard deviation (s) 0.07 0.11 0.41 1.10 8.56 0.12 0.11 0.25 0.39 0.38 0.36 Variation (%) 2.1 3.0 9.0 22.1 101.1 3.1 3.0 6.0 8.8 8.5 8.0 Mechan- Tensile strength (MPa) 62 61 60 59 55 63 57 63 58 55 62 ical Tensile elongation 45 42 35 28 3 10 8 42 6 7 10 property at break (%) Charpy impact 25 22 19 18 3 8 5 3 4 4 2 resistance strength (kJ/m.sup.2)

(28) As shown in Table 2, it is seen that the resin molded article containing the resin composition of Examples has a smaller variation in measurement during the injection molding than the resin molded article containing the resin composition of Comparative Examples. It is also seen that the resin molded article containing the resin composition of Examples is superior in tensile strength, tensile elongation at break, and Charpy impact resistance strength as compared with the resin molded article containing the resin composition of Comparative Examples.

(29) The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.