JPH0733469B2 - Polycarbonate resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a polycarbonate resin composition. More specifically, the present invention relates to a polycarbonate resin composition having excellent antifogging properties and heat stability.

(Prior Art and Problems) Polycarbonate resins are known as engineering plastics excellent in transparency, mechanical strength, particularly impact resistance, heat resistance, etc., and are used in various applications. However, since the surface is not sufficiently hydrophilic, when placed at the boundary between a relatively hot and humid atmosphere and a cold atmosphere,
Haze may occur due to condensation of water, and its transparency may be impaired.

Conventionally, as an additive for imparting antifogging property to plastics, an ester of sorbitan and a fatty acid, or an ethylene oxide adduct thereof has been known, but these are general-purpose resins such as polyvinyl chloride and polyethylene. Polycarbonate resin is an anti-fogging agent for use, and since its molding process is performed at a high temperature near 300 ° C, these anti-fogging agents are decomposed by heat, and not only the anti-fogging effect cannot be achieved. However, there is a possibility that the resin may be discolored, and the strength and the molecular weight may be reduced. Therefore, at present, a polycarbonate resin composition excellent in antifogging property and thermal stability cannot be obtained without impairing the transparency and mechanical properties of the polycarbonate resin.

(Means for Solving Problems) The inventors of the present invention have made earnest studies to improve the antifogging property of a polycarbonate resin, and as a result, when a specific ester compound is blended with the polycarbonate resin, the polycarbonate resin originally has The inventors have found that a polycarbonate resin composition having good anti-fogging properties can be obtained without impairing the excellent transparency, mechanical properties, heat resistance, etc., and have reached the present invention. That is, the gist of the present invention is a diester of an aliphatic carboxylic acid having 10 to 22 carbon atoms and pentaerythritol with respect to 100 parts by weight of an aromatic polycarbonate resin.
A polycarbonate resin composition containing 3 to 3 parts by weight and containing no aromatic polyester.

The present invention will be described in detail below.

The aromatic polycarbonate resin used in the present invention can be obtained by a phosgene method by reacting various hydroxydiaryl compounds with phosgene, or a transesterification method by reacting a dihydroxydiaryl compound with a carbonic acid ester such as diphenyl carbonate. A typical example of the resulting polymer or copolymer is a polycarbonate resin produced from 2,2-bis (4-hydroxyphenyl) propane (bisphenol A).

Examples of the dihydroxydiaryl compound include bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, and 2,2 in addition to bisphenol A.
-Bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3-tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromofel)
Propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-3,5
-Bis (hydroxyaryl) alkanes such as dichlorophenyl) propane; bis (hydroxyaryl) cyclones such as 1,1-bis (4-hydroxyphenyl) cyclopentane and 1,1-bis (4-hydroxyphenyl) cyclohexane Alkanes; 4,4'-dihydroxydiphenyl ether, dihydroxydiaryl ethers such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether; 4,4'4-dihydroxydiphenyl sulfide, 4,4'- Dihydroxydiaryl sulfides such as dihydroxy-3,3'-dimethyldiphenyl sulfide; 4,4'-dihydroxyphenyl sulfoxide, 4,4 '
-Dihydroxydiaryl sulfoxides such as dihydroxy-3,3'-dimethyldiphenyl sulfoxide;
Examples thereof include dihydroxydiarylsulfones such as 4,4′-dihydroxydiphenylsulfone and 4,4′-dihydroxy-3,3′-dimethyldiphenylsulfone.
These dihydroxydiaryl compounds may be used alone or in admixture of two or more, and in addition to these, piperazine, dipiperidine, hydroquinone, resorcin,
You may mix and use 4,4'- dihydroxy diphenyl etc.

Next, in the diester of an aliphatic carboxylic acid having 10 to 22 carbon atoms and pentaerythritol used in the present invention, two of the four hydroxyl groups of pentaerythritol are esterified with the above aliphatic carboxylic acid. It was done.
As the aliphatic carboxylic acid having 10 to 22 carbon atoms, a saturated aliphatic carboxylic acid is preferable from the viewpoint of thermal stability, and a mixture of two or more kinds may be used. Industrially, lauric acid, myristic acid, palmitic acid, and stearic acid are preferable.

The compounding amount of the diester of the aliphatic carboxylic acid having 10 to 22 carbon atoms and pentaerythritol is 0.1 to 3 parts by weight with respect to 100 parts by weight of the aromatic polycarbonate resin, and if the amount is less than this range, a sufficient effect can be obtained. If not, and if the amount is larger than this range, the mechanical properties and thermal properties of the polycarbonate resin deteriorate.

The polycarbonate resin composition of the present invention does not contain other resin such as aromatic polyester, and if necessary, carbon fiber,
Fillers for glass fiber, glass beads, glass flakes, etc., antioxidants, antistatic agents, flame retardants, UV absorbers,
It may contain additives such as carbo black and various colorants.

(Effect of the Invention) According to the present invention, a good anti-fogging effect can be imparted to a polycarbonate resin without impairing the excellent transparency, mechanical properties and thermal stability that the polycarbonate resin originally holds. . Therefore, the composition of the present invention is widely used in the fields of household articles, cooking utensils, toy parts, medical parts, glazings, mirrors, etc. that come into contact with water and water vapor.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples as long as the gist thereof is not exceeded.

Examples 1 to 3 Bisphenol A type aromatic polycarbonate resin having a viscosity average molecular weight of 22,000 (Novalex 7022 manufactured by Mitsubishi Kasei)
A) 100 parts by weight were used, and pentaerythritol diester shown in Table 1 was added thereto in the amounts shown in Table 1 (parts by weight).
Was blended in, and was melt-kneaded at a resin temperature of 280 ° C. and pelletized by a single screw extruder having a cylinder diameter of 40 mm. An injection molding machine with a clamping force of 75 tons (IS75 manufactured by Toshiba Machine Co., Ltd.)
S), resin temperature 280 ℃, mold temperature 80 ℃ 100mm
A flat plate with a corner and a wall thickness of 2 mm was formed.

Using this molded product, the water drop contact angle was measured with an Elma goniometer type contact angle measuring instrument GI type. Also, 40 ℃
The above-mentioned molded product was placed on a beaker containing warm water, and left in a room at 25 ° C for 1 minute, after which the cloudiness of the molded product was visually observed.

Furthermore, for this molded product, using the above injection molding machine,
Test pieces for measuring tensile strength and elongation according to ASTM-D638,
Test piece for impact strength measurement according to ASTM-D256, as well as ASTM
Each of the test pieces for measuring the heat distortion temperature by -D648 was molded, and the physical properties thereof were measured. The results are shown in Table 1.

Comparative Example 1 A molded article was pelletized in the same manner as in Examples 1 to 3 except that the aromatic polycarbonate resin used in Examples 1 to 3 was not blended with pentaerythritol diester at all, and then injection molded. The same measurement as in ~ 3 was performed. The results are shown in Table 1.

Comparative Examples 2 to 5 Instead of the pentaerythritol diester used in Examples 1 to 3, pentaerythritol (Comparative Example 2), pentaerythritol tetrastearate (Comparative Example 3), and sorbitan monopalmitate (Comparative Example 4) were used. , Polyoxyethylene sorbitan monostearate (Comparative Example 5) was blended in the respective quantitative ratios shown in Table 1, and pelletized in the same manner as in Examples 1 to 3, followed by injection molding. The same measurement as in ~ 3 was performed. The results are shown in Table 1.

Comparative Example 6 Clay average molecular weight 21,000 bisphenol A type aromatic polycarbonate resin (Novalex 7022PJ manufactured by Mitsubishi Kasei)
X) 100 parts by weight is used, and 0.5 parts by weight of pentaerythritol monostearate (monoester) is added to this,
The single screw extruder used in Examples 1 to 3 was melt-kneaded at the same temperature and pelletized. For comparison, 100 parts by weight of the aromatic polycarbonate resin was mixed with 0.5 part by weight of pentaerythritol distearate (diester) and melt-kneaded into pellets in the same manner.

When the viscosity average molecular weight (hereinafter simply referred to as the molecular weight) of the above two types of molded articles was measured, the molecular weight of the latter (molded article containing diester) was 21,000, which is the same as the molecular weight of the raw material polycarbonate, whereas the former The molecular weight of the (molded product containing the monoester) was 18,500, and it was confirmed that the molecular weight decreased due to the decomposition of the polycarbonate.

Further, the Izod value at the notch R = 0.1 mm of the above-mentioned two types of molded products is about 90 kg · cm / cm for the molded product containing the diester, whereas the molded product containing the monoester is It became 20 kg / cm / cm or less.

Comparative Example 7 Clay average molecular weight 22,000 bisphenol A type aromatic polycarbonate resin (Novalex 7022PJ manufactured by Mitsubishi Kasei)
X) 100 parts by weight of pentaerythritol tristearate
1.5 parts by weight were compounded, pelletized in exactly the same manner as in Examples 1 to 3 and then injection molded to form a flat plate. This molded product was placed on a beaker containing warm water of 40 ° C., left in a room at 25 ° C. for 1 minute, and then visually observed for cloudiness of the molded product, and a slightly high result was obtained. For comparison, the above polycarbonate resin was blended with pentaerythritol distearate (diester) instead of triester,
The molded product obtained was pelletized in the same manner as above and injection-molded. When the resulting molded product was visually observed for haze by the same method, it was found to be less haze and good in anti-fogging property.

Next, 100 parts by weight of the above polycarbonate resin was mixed with 1.5 parts of pentaerythritol tristearate (triester).
A composition containing parts by weight was prepared. Using a single screw extruder with a cylinder diameter of 40 mm, this composition was heated to a die set temperature of 270
C., screw rotation speed 40 rpm, extrusion rate 8 kg / hr were melt-kneaded and pelletized. Using these pellets, a test piece (color plate) having a thickness of 3 mm was molded by an injection molding machine (J-50 manufactured by Japan Steel Works) at a mold temperature of 100 ° C and a resin temperature of 280 ° C. For comparison, the above polycarbonate resin 10
A composition obtained by blending 0 parts by weight of 1.5 parts by weight of pentaerythritol distearate (diester) was molded in the same manner as above.

The haze of the obtained color plate was measured using a haze meter (Suga Test Instruments). The same operation was carried out for 5 test pieces and the average was obtained. The results are shown in Table 2.
Shown in.

As is apparent from Table 2, the haze value of the molded product containing 1.5 parts by weight of the triester was much higher than the haze value of the molded product containing the same amount of the diester. In addition, it is usually 2 that the haze value is 2
%, And the haze value of the polycarbonate resin alone is usually 1% or less.

From these results, it is understood that the transparency of the molded product containing the triester is clearly inferior to that of the molded product containing the diester. That is, it can be seen that the transparency inherent to the polycarbonate resin is impaired when the triester is blended.

The following is clear from the results of Table 1.

(1) The compositions (Examples 1 to 5) in which the partial ester of petaerythritol was blended with the polycarbonate resin had a small water droplet contact angle. Therefore, the surface has good hydrophilicity, has little clouding even in a high humidity environment, and maintains high transparency. Moreover, the original mechanical properties and heat resistance of the polycarbonate resin are maintained.

(2) On the other hand, the composition containing pentaerythritol tetrastearate (Comparative Example 3) has good mechanical properties but poor antifogging property. Further, the composition containing pentaerythritol (Comparative Example 2), the composition containing sorbitan monopalmitate (Comparative Example 4) and the composition containing polyoxyethylene sorbitan monostearate (Comparative Example 5) were antifogging. Although the property is good, the mechanical strength is significantly reduced due to the decomposition of the polymer during the molding process.

Claims (1)

[Claims] 1. A polycarbonate resin composition containing 0.1 to 3 parts by weight of a diester of an aliphatic carboxylic acid having 10 to 22 carbon atoms and pentaerythritol with respect to 100 parts by weight of an aromatic polycarbonate resin and containing no aromatic polyester. .