JPS59157146A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:A composition having improved stability in a molten state, moldable by extrusion molding without causing strand breakage, providing a molded article having improved transparency, obtained by blending a polyethylene terephthalate with a polycarbonate resin and a carboxylic acid (anhydride). CONSTITUTION:(A) A polyester resin consisting essentially of a repeating unit of ethylene terephthalate is blended with (B) a polycarbonate resin and (C) a carboxylic acid or its anhydride in a weight ratio of A:B=(30-95):(70-5), preferably (35-80):(20-65) and a weight ratio of A+B:C=100:(0.005-0.05). A carboxylic acid such as pyromellitic anhydride containing >=4 carboxylic acid group in the molecule is preferable as the component C. Blending of the three components is carried out at 275-285 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stabilized composition of polynisder resin and polycarbonate resin, and more specifically, to a molded product having no strand breakage and excellent transparency when made from the composition. The present invention relates to a thermoplastic resin composition.

Polyethylene terephthalate has excellent properties such as transparency, surface gloss, gas barrier properties, thermal stability, and chemical resistance.
Because it has an appearance very similar to glass, it is often used in containers and films for food, cosmetics, medical, etc. However, due to its structure, it is highly crystalline and has a high crystallization temperature, so when molded into pipes, rods, sheets, etc., it has poor impact resistance, tensile strength, rigidity, heat resistance, etc. It has the disadvantage that satisfactory fire performance cannot be obtained. Therefore, protrusions are used to compensate for the lack of physical properties by a method of stretching at a high magnification such as by blow molding.

However, depending on the shape of the molded product, there may be localized areas with low stretching ratios, and due to the inherent lack of heat resistance, the product may have an old-fashioned shape during use. There were significant restrictions on the conditions. In order to overcome the drawbacks of conventional polyethylene Lufta V-), a composition blended with polycarbonate resin, which is an amorphous polymer with excellent transparency, heat resistance, impact resistance, and tensile strength, was proposed in JP-A-52-1.
It is known from the publication No. 11956. However, molded products obtained from the composition due to the addition of acid anhydrides have disadvantages such as loss of transparency, which is an excellent feature of polyethylene terephthalate polycarbonate resin, and the tendency to break strands during production of the composition. are doing.

The present inventors have arrived at the present invention as a result of intensive research aimed at solving the above-mentioned drawbacks of polyethylene terephthalate while maintaining as much as possible the excellent transparency of polyethylene terephthalate and polycarbonate resins. That is, the present invention is a thermoplastic resin composition containing as essential components a polyester resin (A) mainly containing ethylene terephthalate repeating units, a polycarbonate resin (B), and calcibon or anhydride thereof (C), The ratio of component (A) and component (B) is (A) : (B) = 30 to 95 near o to 5, and component (C) is component (A) and component CB)
This is a thermoplastic resin composition characterized in that the amount is 0.005 to 0.05 parts by weight based on a total of 100 heavy lid parts.

The composition according to the present invention has excellent stability in a molten state, and can provide a thermoplastic resin composition for molding that has excellent processability, physical properties, mechanical properties, and the like. In particular, the ability to prevent strand breakage during extrusion molding when chipping the composition and the excellent transparency of the resulting molded product are major advantages in manufacturing.

Although the effect of the carboxylic acid or its anhydride used in the present invention has not been fully elucidated, it is thought that it suppresses the decomposition of the polynisder resin in the molten state. However, it is completely surprising that a very small amount of addition can produce a remarkable effect.

The polyester resin used in the present invention includes:
The ethylene terephthalate repeating unit is mainly f+tI, -t
c, soaked in polyester resin, containing not only polyethylene terephthalate but also isophthalate (g* p-
Oxybenzoic acid, diphenylmethane dicarboxylic acid, adipic acid, sepacic acid, naphthalene dicarboxylic acid, etc., or glycol components such as propylene glycol, 'tetramethylene glycol, hexamethylene glycol,
Examples include ethylene terephthalate-based polyester resins copolymerized with neopentylglyconylxane dimetatool, bisphenol A, and the like. Specific examples of copolymerized polyesters include polyethylene prephthalate/inphthalate and polyethylene terephthalate/adipate.

Examples include polyethylene terephthalate/□sebacate, polyethylene terephthalate/butylene terephthalate, etc. It may also be a product copolymerized with a trifunctional or more functional nitrogen-forming component within a range that does not impair moldability. However, it is preferable that the ethylene terephthalate repeating unit be 70 molti or more, and particularly preferably a polyester resin having 85 molti or more.

Alternatively, it may be a mixture of a plurality of polyvarnish resins in which ethylene terephthalate is the main component by blending polyethylene terephthalate with other polyesters. The polynisal tree 8 has an intrinsic viscosity determined at 30° C. in phenol/tetrachloroethane (6/4 weight ratio) of 10% by weight. 4 or more.

Furthermore, it is particularly preferable that the melting point is 0.5 or more, and the melting point is 2
00°C or higher, particularly preferably 240°C or higher.The polynisdel'fltJ resin usually has a carboxylic group content of 40 equivalents/ton or less, and is particularly preferably 30°C or higher.
0 equivalent/ton or less.

In addition, the polycarbonate resin used in the present invention is as follows. 4.4'-dioxydiarylalkane thread polycarbonate) [fat, especially 4.4'-dioxydiphenyl-2,2-propane (commonly known as bisphenol A)
Particularly preferred are polycarbonates. The polycarbonate resin may be produced by any method, but it is preferably produced by the phosgene method or Nisder exchange method. For example, 4,4'-dioxydiphenyl-2,2
-Propane polycarbonate resin id 4, 4'-
A phosgene method in which dioxydiphenyl-2,2-propane is used as a dioxy compound and phosgene is produced in the presence of an aqueous caustic alkali solution and a solvent, or 4.
It is produced by a transesterification method in which 4'-dioxydiphenyl-2,2-probanto-deficient acid cyeneter is transesterified in the presence of a catalyst. In addition, it is preferable that the molecular weight of the polycarbonate resin is usually about 1 sooo or more.

The mixing ratio of the polyester resin and polycarbonate resin is 30 to 95% by weight of the polyester resin and 70 to 5% by weight of the polycarbonate resin. Within this range, it is possible to obtain a molded article that has better thermal stability and dimensional stability than a single polyester resin yarn, and also has excellent mechanical properties.

If the polycarbonate resin content is less than 5% by weight, the molded product is likely to be thermally deformed, resulting in poor dimensional stability and impact resistance.

-If the weight exceeds 70,000, the excellent physical and mechanical properties of polyester resin will be lost.

In particular, the decrease in rigidity is remarkable. Particularly preferred blending amounts are 35 to 80 ml of polyester resin and 20 to 65 ml of polycarbonate resin.

In the present invention, it is important to blend carboxylic acid or its anhydride in addition to the polycarbonate resin and the polycarbonate resin. The carboxylic acid or its anhydride used may be an aliphatic or aromatic carboxylic acid such as stearic acid or terephthalic acid, but
通@ [, (jijE hydrate is preferred. Specific examples of acid anhydrides include capron rf & anhydride, lauric anhydride,
Stearic anhydride, benzoic anhydride, hexahydrophthalic anhydride, phthalic anhydride, 1,8-naphthalic anhydride, trimellitic anhydride, pyromellitic anhydride, cyclobentane atracarboxylic anhydride, glycerin trimellitic anhydride , ethylene glycol binutrimellitic anhydride, benzophenone tetracarboxylic dianhydride, anhydrous n-
Aliphatic or aromatic carboxylic acid anhydrides such as dodecylsuccinic anhydride, maleic anhydride, fumaric anhydride, polycarboxylic acid anhydrides such as polysebacic anhydride, polyprephthalic anhydride, trimellitic anhydride and Examples include acid anhydrides with aliphatic monocarboxylic acids. Particularly preferred acid anhydrides are those of carboxylic acids having at least four carboxylic acid groups in the molecule, such as pyromellitic anhydride. The amount of the carboxylic acid or its anhydride is usually 0.005 to 0.05 parts by weight per 100 parts by weight of the polyester resin and polycarbonate resin. If the compounding lid is less than 0.005 times thick, the effect of suppressing the decomposition of the polyester resin will be insufficient, the transparency of the molded product will be impaired, and the effect of improving impact resistance will not be obtained.

If the amount exceeds 10,000, 0,05 parts by weight, strand breakage occurs frequently during chipping, and transparency also decreases.

As for the method of mixing the above resins and carboxylic acid or its anhydride, for example, the carboxylic acid and/or its anhydride is added to the molten polyester resin before and after the completion of polyester polymerization, and after uniformly mixing, powder is added. A method of adding and melt-mixing polycarbonate resin in the form of polyester, pellet, or molten state, and mixing polyester resin and polycarbonate 1111 resin in powder or pellet form, and then adding carboxylic acid and/or acid anhydride to this. A suitable method is to melt and mix after adding 1 ounce, but
It is not limited to these. No matter which mixing method is used, the temperature at which the polyester resin and carboxylic acid and/or acid anhydride come into contact is usually 270°C.
-290°C, preferably in the range of 275-285°C. In addition, when melt-kneading polyester resin and polycarbonate resin, 1iiiI is usually 1 to 20 minutes,
Preferably, the extrusion time is 2 to 10 minutes, and the mixture is quickly extruded from a melt-kneading machine and formed into a pellet shape, or it is preferably fed directly from a mixer to an injection molding machine or an extrusion molding machine.

In addition, the composition of the present invention may further include various fillers as necessary, such as metal powder, silica, calcium carbonate, kaolin, walanuttonite, Merck, clay, mica, galanu powder, hollow silica, foamed silica, galanu beads, Powder or granular fillers such as carbon black and wood flour, glass fibers, and ash cord fibers.

Fibrous reinforcements such as aramid fibers, whiskers, metal carbide fibers, stabilizers such as heat stabilizers and light stabilizers, colorants, flame retardants, crystallization nucleating agents, lubricants.

Mold release agents, polyfunctional crosslinking agents, rubbery reinforcing agents, other thermoplastic resins, etc. can also be added.

Hereinafter, the present invention will be explained with reference to examples, and all parts in the examples mean parts by weight.

Example 1 Polyethylene terephthalate (η = 0.6, carboxyl group content 25 equivalents/ton) (hereinafter abbreviated as PET) and polycarbonate resin (Mitsubishi Gas Chemical Co., Ltd. bisphenol A polycarbonate molecular weight 24,000) (hereinafter abbreviated as PC) were used, respectively. It was dried under reduced pressure at 130° C. and 21111IH2 for 19 hours. 60 parts of PET and PG dried in this way
1 m of anhydrous pyromellit for 1 part A (Hakai Chemical Co., Ltd. *
Extra Pure Reagent) was added in the proportions shown in Table 1 and mixed thoroughly.

After that, the mixture was extruded using an extruder manufactured by Chuo Kikai Seisakusho (■5K-4).
0) Using a Dalmage screw, the mixture was melt-kneaded at a cylinder temperature of 280°C and an average residence time of about 2 minutes, and extruded into a monofilament with a diameter of 3"Ml. The shape of the strand was good. , quenched in water and cut to obtain pellets.

After drying the pellet thus obtained at 130°C for 15 hours under a reduced pressure of 2 H2,
-75), the mold temperature was set to 30°C, and the ASTM
A tensile test piece for D-638 (1/8 inch thick) was molded. The transparency and haze value (haze value) of the obtained test piece were measured using JIS HAZEMETER-S manufactured by Toyo Seiki Co., Ltd.
It was measured in accordance with K-6714-1977, and the results shown in Table 1 were obtained.

In addition, as comparative examples, PET single molded products and PET
Comparative data for the two-component mixture molded product C and a case where biromesitic anhydride was blended in a large amount are also shown.

If a strand could not be obtained at that time, the lump was crushed and used for molding.

a) 1 m addition part b'>” which is added to 100 parts of the joint of PE″T and l″C: ○: Molten resin is discharged in a strand □ shape (continuous □ string shape) from the nonu-like □ , . □×: The molten resin was discharged from the nozzle in a lump rather than a lump, and the stringiness was not □″.

c) Semi-JIA to JIS K-6714-1977
(Thickness: 1/8 inch) As a result, the composition according to the present invention has good yarn handling properties, and the ease of changing the molecular weight of PC and adjusting the amount of anhydrous bilomeric acid to 0.0'3 PHR is as shown in the example. 1 and □ Melt extrusion and injection molding were performed under the same conditions, and the impact resistance, transparency, and heat distortion temperature (ASTM D-648° load 4.6 ky/ctA') of the obtained molded products were measured. and the result in the second
The results are shown in Table 1. The composition according to the invention exhibits excellent impact resistance and heat distortion temperature fc.

Example 3 Melt extrusion and injection molding were carried out under the same conditions as in Example 1 except that the composition ratio of PET and PC was changed, and the properties of the obtained molded product were evaluated. The results are shown in Table 3.

The composition according to the present invention has good operability, impact resistance,
A molded product with excellent balance of physical properties such as heat distortion temperature and tensile modulus was obtained.

If the PC content is too small, the impact resistance and heat distortion temperature will be insufficient, and if the PC content is too large, the rigidity will be reduced.

Example 4 0.03 part of pyromellitic anhydride was added to 100 parts of the 60/40 weight ratio of 'fcPET and PC used in Example 1, and the same procedure as in Example 1 was made to obtain a sheet with a thickness of 3 mm and a height of 100 mm and 11 mm. Horizontal 1
A flat plate of 001aII+ was injection molded using a film gate. A flat plate was also formed using PET alone in the same manner.

A falling ball analysis was conducted on the obtained flat plate at 23°C, and the results shown in Table 4 were obtained.

Table 4 Falling Ball Impact Strength Test Method Place the sample on a fixed plate with a square shape of SOW and a hole of 35.5 mm in depth. It was sandwiched between a plate and a steel plate, and the whole thing was fixed with four bolts. On the other hand, a ball support guide in which a ball of a predetermined weight was placed on a ball support pin whose crystalline size could be changed at 5 cm intervals was placed on the sample. When the ball support pin is pulled out, the ball falls and impacts the center of the sample. 5crn, 10crn...
...and repeating the falling ball by changing the height at 5cm intervals,
The height at which a crack appeared for the first time in the sample was defined as the falling ball impact height.

Then, the falling ball impact strength was calculated using a linear equation.

Falling ball impact strength (lCg-cw) = ball weight (kf)
X Falling Ball Impact History) The measurement was performed 5 times and the average value was displayed.

Example 5 The two types of flat plates prepared in Example 4 were subjected to boiling water treatment at 100°C to measure changes in transparency over time, and the results are shown in Table 5.

Table 5 The transparency of the products of the present invention was determined even after treatment with boiling water at 100°C.
Translucency is maintained for a long time, and unlike PET, it does not suddenly devitrify.

Example 6 Melt extrusion and injection molding were carried out under the same conditions as in Example 2 except that pyromellitic anhydride was added at 0.03 P'HR using PC with a molecular m22000, and ASTM D-638
A tensile test piece (1/8 inch thick) was obtained. The obtained tensile test piece was heat treated in an oven at 100°C for 2 hours, and the dimensional change rate in the longitudinal direction was measured, and the results are shown in Table 6. Got the results. As a comparative example, a test piece made of PET alone was also molded and subjected to a comparative test.

Table 6 The molded products obtained from the compositions of the present invention have extremely small post-shrinkage, so even when the molded products are used at around 100°C, they do not deform (
It is clear that it is difficult to

Patent applicant: Toyobo Co., Ltd.

Claims (1)

[Scope of Claims] 1. Polyvarnish 1ru tree 8m (A) and polycarbonate tree 8m (B
) and a carboxylic acid or its anhydride (C) as essential components, wherein the ratio of component (A) to component (B) is (A) J CB ) = 30 to 95:
70 to 5 weight ratio, and component (C) is 0.0.05 to 0 with respect to 100 parts by weight of component (A) and component (B) in total.
．． 05 parts by weight of a thermoplastic resin composition. 2. The thermoplastic m-finger composition according to claim 1, wherein the carboxylic acid or its anhydride is a polycarboxylic anhydride.