JPS636049A - thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide the title compsn. having excellent flexural strength, flexural modulus and appearance and suitable for use as a material for electronic and electrical components, camera bodies, etc.., by blending an arom. polycarbonate resin with tunnel structure type potassium titanate fiber. CONSTITUTION:99-50pts.wt. arom. polycarbonate resin (A) obtd. by starting from bisphenol A is melt-kneaded with 1-50pts.wt. tunnel structure type potassium titanate fiber (B) having the formula K2Ti6O13 and such a structure that titanic acid forms a tunnel structure and K component is confined in the tunnel, in Banbury mixture, a roller or an extruder.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermoplastic resin composition that has excellent mechanical properties, particularly flexural strength and flexural modulus, and has excellent heat resistance,
The present invention provides a material suitable for parts of electronic and electrical equipment that require dimensional accuracy and bending modulus, such as connectors, chassis, and camera bodies.

[Conventional technology and its problems]

As is well known, aromatic polycarbonate resin is tough, has excellent impact resistance, electrical properties, and has good dimensional stability.
Since it also has excellent transparency, it is widely used as a useful engineering plastic.

However, it is unsuitable for applications that require high dimensional accuracy and flexural modulus, and glass fibers are added to connectors, chassis, camera bodies, etc. that require these characteristics. However, this composition had the disadvantage that fibers were likely to stand out on the surface of the molded product.

As a solution to this problem, a method has been proposed to add potassium titanate fibers with a thin fiber diameter of about 2.0 mm, but conventional potassium titanate fibers with the structural formula of KzTi, Og have a layered structure. Since the K component was exposed on the fiber surface, the polycarbonate resin component was hydrolyzed and a good composition could not be obtained.

[Means for solving problems]

As a result of intensive studies to obtain a composition of polycarbonate resin with high bending strength and high bending elastic modulus and excellent appearance, the present invention found that it is effective to add potassium titanate fibers having a tunnel structure. The present invention has been completed.

That is, the present invention provides a thermoplastic resin composition comprising A, 99 to 50 parts by weight of an aromatic polycarbonate resin, and B, 1 to 50 parts by weight of tunnel-structured potassium titanate fibers.

The present invention will be explained in detail below.

A, aromatic polycarbonate resin of the present invention is an optionally branched thermoplastic polycarbonate polymer made by reacting aromatic dihydroxy or a small amount of a polyhydroxy compound with a diester of phosgene or carbonic acid. An example of an aromatic dihydroxy compound is
2,2-bis(4-hydroxyphenyl)propane (=
Bisphenol A), Tetramethylbisphenol A1
Tetrabromobisphenol A1bis(4-hydroxyphenyl>-p-diisopropylbenzene, hydroquinone, resorcinol, 4,4-dihydroxydiphenyl, etc., and bisphenol A is particularly preferred.

In addition, to obtain a branched aromatic polycarbonate resin, phloroglucin, 4.6-cymethyl-2.4.6-
) li (4-hydroxyphenyl)hebutene-2,4
, 6-dimethyl-2.4.6-tri(4-hydroxyphenyl)hebutane, 2,6-dimethyl-2.4.6
- ) li (4-hydroxyphenyl)hebutene-3
, 4,6-dimethyl-2.4.6-tri(4-hydroxyphenyl)hebutane, 1,3.5-tri(
Polyhydroxy compounds such as 4-hydroxyphenyl)benzene, 1,1,1-tri(4-hydroxyphenyl)ethane, and 3,3-bis(4-hydroxyaryl)oxindole (isatin bisphenol) , 5-chloroisatin, 5,7-dichloroisatin, 5-bromiisatin, etc., a part of the dihydroxy compound, for example 0.1 to 2 mol %, is replaced with a polyhydroxy compound. Furthermore, monovalent aromatic hydroxy compounds suitable for controlling the molecular weight include m- and p-methylphenol, m- and p-propylphenol, p-bromophenol, p-tert-butylphenol and p-long-chain alkyl-substituted Phenol and the like are preferred. A typical aromatic polycarbonate resin is bis(4
-Hydroxyphenyl)alkane-based dihydroxy compounds, especially polycarbonates whose main raw material is bisphenol A, polycarbonate copolymers obtained by using two or more aromatic dihydroxy compounds together, and small amounts of trivalent phenol-based compounds used in combination. Also mentioned are branched polycarbonates obtained by Aromatic polycarbonate resins may be used as a mixture of two or more types.

The tunnel structure potassium titanate fiber of the B component of the present invention has a structural formula of KzTibO+3, in which titanic acid forms a tunnel structure and the K component is confined inside this tunnel.

A specific example of the properties of this tunnel structure potassium titanate fiber is as follows.

Structural formula: KzTi60t:+ Crystal system: Monoclinic Space group: Cz/m Lattice constant: a = 15.582 people, b = 3.82 people,
C・9.112 people, β・99.764 'Number of molecules in unit cell: 2 Such a tunnel structure potassium titanate fiber is commercially available from Titan Kogyo under the product name rHT-300J rHT-30.
0E J rHT-200J is preferably used.

The ratio of the thermoplastic resin composition of the present invention is A, the aromatic polycarbonate resin is 99 to 50 parts by weight, preferably 95 parts by weight.
~60 parts by weight, and the tunnel structure potassium titanate fiber B is in the range of 1 to 50 parts by weight, preferably 5 to 40 parts by weight. A. If the component is less than 50 parts by weight, molding processability deteriorates, so it is preferable, and B.

If the amount of the component is less than 1 part by weight, the effect of improving bending strength and bending elastic modulus will be insufficient.

The thermoplastic resin composition of the present invention as described above may contain various additives such as stabilizers, pigments, dyes, flame retardants, and lubricants, reinforcing materials such as inorganic or organic fiber substances, glass beads, etc., as desired. Various fillers may be blended, and further, other resin components may be blended within a range that does not impair the characteristics of the present invention. For example, polycarbonate from bisphenol A or tetrabromobisphenol A.
Examples include adding oligomers to improve moldability, flame retardance, and surface properties, and adding heat-resistant polyesters such as polyester carbonate and polyarylate (for example, product name: U Polymer, Unitika@) to improve heat resistance. .

In preparing the thermoplastic resin composition of the present invention,
Any conventionally known method may be used, and methods of kneading using an extruder, Banbury mixer, rolls, etc. may be selected as appropriate.

〔Example〕

Examples and comparative examples will be described below, and "parts" are based on weight unless otherwise specified.

Examples 1 to 3 and Comparative Example 1.2 Aromatic polycarbonate resin made from bisphenol A (manufactured by Mitsubishi Gas Chemical, trade name Newpiron S-20)
00, molecular weight 25,000, written as Ding S-200 old)
and tunnel-structured potassium titanate fibers (manufactured by Titan Kogyo ■, product names: HT-300 and IT-300E, respectively referred to as rHT-300J and rHT-300E J) were placed in a blender at the ratio shown in Table 1, and 30 Mixed for a minute.

The obtained mixture was supplied to a 40 tmm pent extruder and melt-kneaded at a cylinder temperature of 240 to 260°C to form pellets. The pellets were dried in a hot air dryer at 110°C for 5 minutes.
After drying for more than an hour, a test piece for measuring physical properties was molded by injection molding. The test results are shown in Table 1.

For comparison, aromatic polycarbonate resin alone (Comparative Example 1
) and layered structure potassium titanate fiber (manufactured by Daijin Chemical Co., Ltd., trade name: Tismo D101, rDlolJ) in place of the tunnel structure potassium titanate fiber in Example 1. (Comparative Example 2) was also the same as in Example. Pellets and test pieces were prepared using the method and their physical properties were measured. The test results are shown in Table 1.

In addition, the description in the table is as follows.

σT: Tensile strength unit: kg/cni.

ε: Tensile increase unit %.

:Bending strength unit: kg/cJ.

Y: Flexural modulus unit x 103 kg/ad.

CC1J medium bending strength: unit kg/cj Appearance: Visually observe the appearance of the molded product.

○: Good, ×: Decomposed, colored brown [Operations and effects of the invention] As is clear from the above detailed description, examples, and comparative examples, the composition of the present invention has a higher bending strength than polycarbonate resin. The composition has improved flexural modulus and no deterioration in appearance.

Claims (1)

[Claims] A, 99 to 50 parts by weight of aromatic polycarbonate resin and B
, and 1 to 50 parts by weight of tunnel-structured potassium titanate fibers.