JPS6270446A - Polycarbonate composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which has excellent thermal stability and free of an objectionable smell, by blending a polycarbonate with an org. phosphine oxide. CONSTITUTION:A polycarbonate (A) having a homopolymer, copolymer or branched structure, obtd. by reacting a dihydric phenol (e.g., hydroquinone) with a polycarbonate precursor (e.g., phosgene) is blended with 0.00001-0.01wt%, pref. 0.00001-0.01wt% (in terms of phosphorus atom) org. phosphine oxide (B) of the formula [wherein R<1>-R<3> are each a (substd.) hydrocarbon group] (e.g., tributyl phosphine oxide), and optionally, additives such as other polymers, a stabilizer, an ultraviolet absorber, a parting agent, a flame retarder, an antistatic agent, a dye, a pigment, etc., an inorg. filler such as talc, silica or glass powder, a reinforcing agent such as glass fiber, carbon fiber or aramid fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to stabilized polycarbonate compositions, and more particularly to polycarbonate compositions stabilized by incorporating small amounts of organic phosphine oxides. .

<Prior art> Various types of heat stabilizers have been proposed for polycarbonate, but organic phosphites are the mainstream in practical use.
Other stabilizers were used only supplementally. Organic phosphites, which predominate, dramatically improve the thermal stability of polycarbonate and give polycarbonate an excellent hue, but their hydrolyzates accelerate decomposition, reducing the boiling water resistance and moist heat resistance of polycarbonate. , which has the disadvantage of impairing transparency. Organic phosphonites, which are similar to organic phosphites, do not exhibit any thermal stabilizing effect, but show excellent color stabilizing effects on polycarbonates colored with dyes and pigments. Like organic bosphites, phosphonoyl 1~ also has the disadvantage of accelerating hydrolysis.Also, organic phosphates in the form of oxidized organic phosphites have almost no effect; The excellent stabilizing effect of polycarbonate containing inorganic fillers or glass fibers, etc., is not as good as that of organic phosphite.However, recently polycarbonate has been used for, for example, lenses, disk substrates for information recording, etc. As the degree of purification of polycarbonate itself has improved, the above-mentioned organic phosphonite and organic phosphite 1~ have been reconsidered as stabilizers. Can not do it.

Unlike these ester-based organophosphorus compounds, organic phosphines that do not have any ester bonds have been proposed (for example, Japanese Patent Publication No. 47-22088, Japanese Patent Application Laid-Open No. 48-90).
350, JP-A-57-49649). These organic phosphines have attracted attention as they improve the thermal stability of polycarbonate and do not cause hydrolysis, but they have not been put to practical use because of their strong unpleasant odor.

<Object of the Invention> An object of the present invention is to provide a stabilized polycarbonate composition containing an excellent heat stabilizer that does not substantially cause unpleasant odor and does not promote hydrolysis. Ru.

<Structure of the Invention> The present invention is a polycarbonate composition characterized in that an organic phosphine oxide is blended into polycarbonate.

The polycarbonate used in the present invention is obtained by reacting a dihydric phenol with a carbonate precursor such as phosgene or diphenyl carbonate.

An example of dihydric phenol is hydroquinone.

Dioxydiphenyl, bis(hydroxyphenyl)methane, 1,2-bis(hydroxyphenyl)ethane,
2.2-bis(hydroxyphenyl)propane, 2,
2-bis(hydroxyphenyl)butane, 2,2-bis(hydroxyphenyl)hexane, 1,1-bis(
hydroxyphenyl) cyclohexane, bis(hydroxyphenyl) ether, bis(hydroxyphenyl) ketone, bis(hydroxyphenyl) sulfide, bis(
hydroxyphenyl) sulfone, α,α′-bis(hydroxyphenyl)diisopropylbenzene.

Substituents such as lower alkyl and halogen may be mentioned. Further, a part of phosgene may be replaced with terenothalic acid chloride, isophthalic acid chloride, etc. Thus, the polycarbonate used in the present invention may be a homopolymer or a copolymer, and may even have a branched structure.

=3 The organic phosphine oxide used in the present invention is a compound represented by the following general formula (1). Specifically, triethylphosphine oxide, tributylphosphine oxide, trioctylphosphine oxide, tricyclohexylphosphine oxide, dimethyl-phenylphosphine oxide, dibutyl-phenylphosphine oxide, diphenyl-methylphosphine oxide, diphenyl-octylphosphine oxide. , diphenyl-benzylphosphine oxide, phenyl-naphthyl-benzylphosphine oxide, triphenylphosphine oxide.

Tris(tolyl)phosphine oxide, tris(2,4
-dimethylphenyl)phosphine oxide, tris(nonylphenyl)phosphine oxide, trinaphthylbosphine oxide, tris(methoxyphenyl)phosphine oxide, diphenyl-acetoxymethyl-phosphine oxide.

Examples include diphenyl-(β-ethylcarboxyethyl)phosphine oxide, tris(chlorophenyl>phosphine oxide, diphenyl-(hydroxyphenyl)phosphine oxide, methyl-phenyl-methoxyphenylphosphine oxide, etc. These may be used alone or in combination. The preferred blending amount is 0.00001 to 0.1% by weight, more preferably 0.00001 to 0.1% by weight of phosphorus atoms, based on the weight of the polycarbonate.
00001 to 0.01% by weight, more preferably 0.00
005 to 0.005% by weight.

These organic bosphine oxides have much less odor than the corresponding organic phosphines, and no unpleasant odor is felt even when they are blended in an amount of about 1% by weight with respect to polycarbonate. In addition, phosphorus in organic phosphine is trivalent and has reducing properties, whereas phosphorus in organic phosphine oxide is 5-valent.
value and no longer has reducibility. Nevertheless, it is quite surprising that organic phosphine oxides exhibit a stabilizing effect comparable to that of organic phosphines. 5
Trimedel phosphate, which has a high phosphorus content, has a weak stabilizing effect on polycarbonate alone, but has an excellent effect when containing inorganic substances, whereas organic phosphine oxide has a weak stabilizing effect on polycarbonate alone. It also shows the same stabilizing effect as organic phosphites,
Also, it is unpredictable.

The composition of the present invention is obtained by blending an organic phosphine oxide with a polycarbonate.

As a blending method, conventionally known means can be used. That is, polycarbonate powder or pellets and organic phosphine oxide are mixed using a cylindrical mixer, a Nauta mixer, a double cone mixer, a V-type mixer, a Henschel mixer, a ribbon mixer, etc. The most common method is to melt-mix polycarbonate and organic bosphin oxide using a melt extrusion method and extrude to pelletize. A method of adding it to an organic solvent solution of polycarbonate obtained by the phosgene method and removing the solvent can be used.

The composition of the present invention may optionally contain other polymers.

For example, olefin polymers, styrene polymers, acrylic polymers, olefin rubbers, diene rubbers,
Acrylic rubber, ester rubber.

Their graft polymers, aromatic polyesters.

Aromatic polyether, aromatic polysulfone, etc. can be added, and in addition, other stabilizers, UV absorbers, mold release agents, flame retardants, antistatic agents, dyes and pigments, talc, etc. that are usually added to polymers can be added. Inorganic fillers such as silica and glass powder, reinforcing materials such as glass fibers, carbon fibers, and aramid fibers can be blended. Particularly, the addition of partial esters of higher fatty acids and polyhydric alcohols, epoxy compounds, and oxetane compounds is effective for stabilizing polycarbonates containing halogens.

<Effects of the Invention> Since the composition of the present invention contains a chemically relatively stable organic phosphine oxide, it does not decompose polycarbonate in the presence of moisture like organic phosphites and organic phosphonites, and does not cause cloudiness. Without any pressure, and
It has virtually no unpleasant odor like that of organic phosphines, improves the heat resistance stability of polycarbonate, and therefore causes only a slight decrease in molecular weight during molding, improving the hue of molded products. Due to such excellent effects, the composition of the present invention can be fully used in application fields where conventional polycarbonates containing organic phosphites cannot be used, and will greatly contribute to the development of polycarbonates. It is.

Example 1 The present invention will be explained below with reference to Examples and Comparative Examples. In addition, evaluation of heat resistance and hydrolysis resistance was performed by the following method.

Evaluation of heat resistance using a 3-ounce injection molding machine (manufactured by Anchorberg)
It was molded into a sample plate with a thickness of 2#1, a width of 50 m, and a length of 70 mm at a molding temperature of 340°C. To evaluate thermal stability,
The hue of the sample plate molded after residence in the cylinder of the molding machine for 10 minutes (1-', a').

b') and the hue of the sample plate molded without stagnation (L).

Measure a and b) with a color difference meter (manufactured by Color Machine Co., Ltd.) 'r'',
The degree of discoloration was compared using ΔF=-+a-a'2+ (lower-7-7-7).The hue was expressed by the b value.

The smaller the b value, the smaller the coloring direction.

Evaluation of Hydrolysis Resistance The non-stagnation sample plate obtained in the heat resistance evaluation was treated in a steam sterilizer at 120° C. for 11 hours, and then the viscosity average molecular weight and haze (1-1aze) were measured.

Measurement of viscosity average molecular weight The specific viscosity ηsp of a methylene chloride solution of the resin at 20° C. was measured using an Ostwald viscometer, and the average molecule 1 [M] was calculated from the following relational expression.

ηsp/C = [η] + '[η]2C... (1) However, K' = 0.45, C = 0.7g/old [η]
= 1,23 X 10-'[M]""
...(2) Haze measurement Nippon Seimitsu Kogaku integrating sphere type)-1, T, R meter 5EP
-H.2 type was measured according to ASTM-D-1003 and expressed as %r.

Examples 1-5. Comparative Examples 1-2 Polycarbonate powder obtained from bisphenol Δ was blended with a heat stabilizer in the proportions listed in Table 1, mixed in a dumbler, and then melted and kneaded in a 30-threshold φ extruder to pelletize the resulting pellets. A sample plate was molded at a molding temperature of 340° C. using a 3-ounce injection molding machine manufactured by Annokobel 9 Co., Ltd., and evaluated using the method described above. The results are shown in Table 1.

Comparative Examples 3-4 The same procedure as in Example 3 was carried out except that a heat stabilizer other than organic sphine oxide was added, and the results are shown in Table 1.

(Margin below) Procedural amendment January 1986

Claims (1)

[Claims] A polycarbonate composition characterized by blending a small amount of organic phosphine oxide with polycarbonate.