JPH04202476A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain the title compsn. for molding with excellent heat resistance, dispersibility and mechanical strength by adding a specified amt. of a specified TiO2 to the composition. CONSTITUTION:The title compsn. is constituted by compounding 0.001-30wt.% TiO2 treated with a polyorganosiloxane (e.g. methylhydrogenpolysiloxane) based on the total amt. of the compsn. in a thermoplastic resin compsn. (e.g. one contg. a polycarbonate).

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a thermoplastic resin for molding in which titanium oxide powder is well dispersed and thermal stability is improved by using titanium oxide treated with polyorganosiloxane. It is a composition having excellent mechanical strength, heat resistance, electrical properties, surface appearance, etc., and can be suitably used in a wide range of industrial fields.

[Conventional technology and its problems]

Conventionally, it has been widely practiced to add titanium oxide to thermoplastic resins to color them or to impart light-shielding properties.
However, there are chemically active sites on the surface of titanium oxide,
This causes a problem in that the physical properties of the thermoplastic resin deteriorate due to a decrease in molecular weight under heating and melting conditions during molding.

In addition, the dispersibility in the matrix resin was poor, and roughening of the surface of the molded product was sometimes observed.

Although it is known to treat titanium oxide with a silane coupling agent in order to improve these points, it has not been possible to sufficiently prevent thermal deterioration of the matrix resin.

Therefore, there has been a desire for titanium oxide that does not deteriorate thermoplastic resins when heated and provides a good appearance to molded products.

[Means to solve the problem]

The present inventors have conducted intensive studies on methods for solving the above-mentioned drawbacks, and as a result, have arrived at the present invention.

That is, a thermoplastic resin for molding is obtained by blending titanium oxide (b) treated with polyorganosiloxane into a thermoplastic resin composition (a) in an amount of 0.001 to 30% by weight based on the entire composition. It is a composition.

The thermoplastic resin composition of the present invention includes a polycarbonate resin, a polyester resin, a polyoxymethylene resin, or an alloy resin based on these resins, and further includes various thermoplastic resins, elastomers, reinforcing materials, fillers, and others. It is a thermoplastic resin composition formed by appropriately blending.

The polycarbonate resin is produced by the same method as the conventional method for producing polycarbonate resin, that is, by reacting an aromatic dihydric phenol compound with phosgene or carbonic acid diester. The aromatic homo- or copolycarbonate resin used in the present invention preferably has a viscosity average molecular weight in the range of 19.000 to 30.000 as measured with a methylene chloride solvent.

The polyester resin is produced by a method similar to the method for producing conventional polyester resins, that is, by subjecting an aromatic or aliphatic diol to an aromatic or aliphatic dibasic acid to a polycondensation reaction. Examples of the polyester resin used in the present invention include polybutylene terephthalate and polyethylene terephthalate, which have an intrinsic viscosity of 0.7 to 1.2 when measured with a mixed solvent of phenol/tetrachloroethane (volume 6/4). It is preferable that the

The polyoxymethylene resin is produced by the same method as the conventional method for producing polyoxymethylene resin, that is, by homopolymerizing or copolymerizing trioxane or high-purity formaldehyde. As a homopolymer, one whose molecular terminal end is stabilized by a treatment such as acetylation can be used. A copolymer type polyoxymethylene obtained by copolymerizing trioxane, a cyclic ether, and a cyclic formal is particularly suitable because it has excellent thermal stability.

The polyorganosiloxane used in the present invention has 4 S1 atoms.
or more. Titanium oxide treated with the polyorganosiloxane of the present invention is produced by a sulfuric acid method or a chlorine method, and is surface-treated or its surface is treated with silicon oxide, aluminum oxide, zinc oxide, zircon oxide, or even an organic substance. The particle size is 0.2 to 0.5 μm, and the particles are treated with polyorganosiloxane.

The polyorganosiloxane treatment of the present invention may be carried out by either a wet method or a dry method. In the wet method, untreated zinc oxide whiskers are immersed in a solution of polyorganosiloxane in a low-boiling solvent, followed by desolvation. In addition, in the case of a dry method, adhesion is performed by mixing titanium oxide and polyorganosiloxane in a mixer such as a Henschel mixer, super mixer, or V-type blender, or by spraying an organic solution of polyorganosiloxane. After 100~250℃
Heat treatment is performed at a temperature of .

Note that it is also possible to include a compound that accelerates the curing of the polyorganosiloxane, exemplified by dibutyltin dilauryl, tetraalkoxytitanium, etc., in the organic solvent solution of the polyorganosiloxane. Examples of the polyorganosiloxane include polyorganohydrogensiloxane, cyclic organosiloxane, cyclic organohydrogensiloxane, or polyhydrocarbon oxysiloxane, including methylhydrogenpolysiloxane, methylpolycyclosiloxane,
Examples include methylhydrodienepolycyclosiloxane and methylmethoxypolysiloxane.

The amount of zinc oxide whiskers in the entire composition is 0.00
It ranges from 1 to 30% by weight, preferably from 0.01 to 20% by weight. The amount of zinc oxide whiskers is 0.001
If it is less than 30% by weight, the effect of addition as a colorant, light shielding agent, or filler will be insufficient, and if it is used in excess of 30% by weight, fluidity will decrease and moldability will deteriorate.

The present invention is made by blending polyorganosiloxane-treated titanium oxide into a resin composition containing a polycarbonate resin, a polyester resin, a polyoxymethylene resin, or an alloy resin based on these.
Other thermoplastic resins, various elastomers, reinforcing materials, additives, etc. can be added as necessary. Other thermoplastic resins include styrene resins such as PS, old PS, AS, and ABS, acrylic resins such as PMMA; PE, P
Polyolefin resins such as P; examples include thermoplastic resins such as polyphenylene ether, polyphenylene sulfide, polysulfone, polyether sulfone, polyurethane, and other engineering plastics, and these may be used alone or in combination as appropriate. Ru.

The composition of the present invention is prepared using the above ingredients, but
The preparation method may be a usual method and is not particularly limited, but for example, (a), (b) and other additive components as appropriate are sufficiently mixed using a mixing means such as a V-blender, and then mixed with a vent-type screw extruder. A method of pelletizing or preparing a mixture of component (a) and other additive components in advance using a powerful mixing means such as a super mixer, ) and other fiber reinforcing materials, and a method generally used industrially, such as a method of mixing and pelletizing the mixture, can be appropriately applied.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to Examples. Note that parts in the examples are based on weight unless otherwise specified.

Example 1 Titanium oxide (manufactured by Sakai Kagaku ■, Titon 5R-1, hereinafter "T")
10 □) was added to methylhydrodiene polysiloxane (manufactured by Shin-Etsu Chemical ■: Shin-Etsu Silicone Oil KF-99).
, hereinafter referred to as rKF-99J) in a methylene chloride solution prepared at a concentration of 2%, the solvent was removed and dried to obtain polysiloxane-treated TiO□ (TiO7-81).

Polycarbonate resin powder made using bisphenol A (manufactured by Mitsubishi Gas Chemical, trade name: Kneepilon S-200)
0, viscosity average molecular weight 24,000, hereinafter referred to as "rpc") and the above TiO□-31 in the ratio shown in Table 1, mixed in a tumbler, and viscosity average molecular weight 230 to 250 It was extruded into pellets at ℃.

The obtained pellets were heat treated in a nitrogen stream at 340° C. for 1 hour, and the viscosity average molecular weights before and after this treatment were measured and are shown in Table 1.

Further, the obtained pellets were dried in a hot air circulation dryer at 120° C. for 5 hours and then injection molded to obtain test pieces. The bending strength and Izot impact strength of the obtained molded product were measured and the results are shown in Table 1.

In addition, the state of dispersion of TiO□-81 in the resin was visually observed using the obtained plate-shaped molded product, and the results are shown in Table 1.

Example 2 Titanium oxide was stirred in a super mixer and then KF-
99 and polysiloxane treated T102 (T
The same procedure as in Example 1 was conducted except that i02-S2) was obtained.

Comparative Example 1 For comparison with Examples 1 and 2, the same procedure as Example 1 was conducted except that untreated TlO□ was used.

Examples 3 to 4, Comparative Examples 2 to 3 PC, the above TiO□-31, and glass fiber as its reinforcing material (manufactured by Asahi Fiberglass ■; C303MA40)
9C1 length 3mm, hereinafter referred to as rGFJ), carbon fiber (manufactured by Toho Rayon ■; Besphite HTA-C6-3
R3 (hereinafter referred to as rcFJ) were blended in the proportions shown in Table 3, mixed in a tumbler, and extruded into pellets at 230 to 250°C using a 40 mmφ vented shaft extruder.

For comparison, Table 2 also shows the results of the same procedure as above except that untreated 7102 was used.

Example 5, Comparative Example 4 Polyester resin using terephthalic acid and butanediol (manufactured by Polyplastics ■, trade name: DURANEX 2002, intrinsic viscosity η, /C=1.0a/g,
rPBT J) and the above TlO2Sl were blended in the ratio shown in Table 3, mixed in a tumbler, and made into a 40mmφ
The pellets were extruded at 230 to 250°C using a vented shaft extruder.

2 g of the obtained pellets were taken, dissolved with stirring in a mixed solvent of phenol/tetrachloroethane (volume 6/4), and filtered through a glass filter to remove TlO2.

Filtration and intrinsic viscosity were measured.

Table 3 also shows the results of the same procedure as above except that untreated TlO2 was used for comparison.

Example 6, Comparative Example 5 Polyester resin made using terephthalic acid and ethylene glycol (manufactured by Nippon Unipet Mari, trade name, RT-5
43, intrinsic viscosity ηsP/C=0.76 a/g, hereinafter “
PET J) and the above-mentioned TlO2Sl were blended in the ratio shown in Table 3, mixed in a tumbler, and extruded at 230 to 250°C using a 40 mmφ vented screw extruder to obtain pellets/soto.

Table 3 also shows the results of the same procedure as above except that untreated TiO□ was used for comparison.

Example 7, Comparative Example 6 Polyoxymethylene resin which is a copolymer of trioxane and cyclic ether (manufactured by Mitsubishi Gas Chemical, trade name: Iupital F20-02, intrinsic viscosity η5°/C = 1.4
2 a/g, hereinafter referred to as "rPOM") and the above TiO□-
81 in the proportions shown in Table 4, mixed in a tumbler, and extruded at 200°C in a 40 mm diameter vented shaft extruder to form pellets.

2 g of the obtained pellets were taken and heated in a test tube at 222° C. for 30 minutes under N2 atmosphere. After heating, the polymer was taken out and frozen and crushed. This sample 1
120 g in benzyl alcohol at 100 mA.
The mixture was stirred and dissolved at ℃ for 30 minutes, and TiO□ was removed by hot filtration using a class filter. After filtration and cooling, the precipitated polymer was washed with acetone, dried in vacuum, and then its intrinsic viscosity was measured at 60°C in p-chlorophenol containing 1%-pinene.

The results are shown in Table 4.

Table 1 Indicates the degree of compatibility with umbrella resin.

Table 2 Table 3 Table 4 [Effects of the Invention] The composition of the present invention has excellent heat resistance, dispersibility, and mechanical strength. The composition of the present invention can be effectively used as a molding material for mechanical parts, electrical and electronic parts, and household goods.

Patent applicant: Mitsubishi Gas Chemical Co., Ltd.

Claims (6)

[Claims] (1) Thermoplastic for molding made by blending titanium oxide (b) treated with polyorganosiloxane into a thermoplastic resin composition (a) in an amount of 0.001 to 30% by weight based on the entire composition. resin composition (2) The thermoplastic resin composition for molding according to claim 1, wherein the thermoplastic resin composition (a) contains a polycarbonate resin, a polyester resin, a polyoxymethylene resin, or an alloy resin mainly composed of these. (3) The thermoplastic resin composition for molding according to claim 1, wherein the polyorganosiloxane is a polyorganohydrogensiloxane, a cyclic organosiloxane, a cyclic organohydrogensiloxane, or a polyhydrocarbonoxysiloxane. (4) The thermoplastic resin composition according to Claim 1, wherein the amount of polyorganosiloxane treated in the titanium oxide treated with polyorganosiloxane is 1 to 10% by weight based on the entire treated titanium oxide. (5) The thermoplastic resin composition for molding according to claim 1, wherein the thermoplastic resin contains an inorganic or organic reinforcing material. (6) The thermoplastic resin composition according to claim 1, wherein the reinforcing material is glass fiber or carbon fiber.