JP2701300B2 - Optical molding materials - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a polycarbonate resin molding material having excellent heat resistance and moldability suitable for producing optical molded products such as optical disks, lenses, and prisms.

[Conventional technology and its problems]

Recently, polycarbonate resin has taken advantage of its features such as transparency, heat resistance, hydrolysis resistance, and dimensional stability,
It has been widely used as a lens, a substrate material for optical information discs, and the like, and accordingly, improvement in thermal stability and releasability has become an important problem.

Conventionally, organic phosphites have been mainly used as a stabilizer for polycarbonate in practice, but it is well known that this hydrolyzate promotes decomposition of polycarbonate itself. When the polycarbonate resin is hydrolyzed, the decomposed product precipitates as fine white spots in the molded product and hinders the passage of light.

Phosphonite compounds proposed as other than organic phosphites have the same hydrolyzability, and organic phosphines and organic phosphine oxides have the drawback that heat stability is insufficiently improved. Heating results in a noticeable yellowing.

On the other hand, optical molded products, especially optical disks, lenses, etc. are manufactured by injection molding. However, when releasing from a mold, a large release resistance causes warpage of molded products and optical distortion. , The use of a release agent is required. In particular, in the case of an optical disk, it is necessary to accurately transfer irregularities of 1 μm or less on the stamper, and this largely depends on the performance of the release agent.

Conventionally, as a release agent for a polycarbonate resin, paraffin, silicone oil, fatty acid, fatty acid ester, fatty acid partial ester (particularly, fatty acid monoglyceride) and the like have been known. Among these, fatty acids and fatty acid monoglycerides having excellent mold release properties when used in small amounts are polycarbonate resins under high temperature and high humidity (80 ° C).
(90% RH) promotes hydrolysis of the polycarbonate resin. Therefore, it is not preferable to add more than 0.01 part by weight based on 100 parts by weight of the polycarbonate resin. However, from the viewpoint of releasability, it is preferable to add more than this amount, for example, about 0.04 parts by weight.

In addition, paraffin, silicone oil, fatty acid esters, etc. have insufficient release effect, and polycarbonate resin
It is preferable to add 0.2 parts by weight or more to 100 parts by weight,
With such an added amount, there is a disadvantage that a flow mark is easily generated on the surface of the molded article.

[Problems to be solved by the invention]

An object of the present invention is to provide an optical polycarbonate resin molding material which is excellent in moldability, particularly mold release property and transfer property, and is also excellent in heat resistance and hydrolysis resistance.

[Means for solving the problem]

The present invention relates to (1) phosphoric acid 0.0005 to 100 parts by weight of a polycarbonate resin having a viscosity average molecular weight of 12,000 to 23,000.
0.01 parts by weight, (2) 0.001 to 0.01 parts by weight of a partial ester of a saturated fatty acid having 10 to 22 carbon atoms and a polyhydric alcohol, and (3) monovalent or a saturated fatty acid having 10 to 30 carbon atoms and 30 or less carbon atoms An optical molding material comprising 0.005 to 0.2 parts by weight of an ester with a polyhydric alcohol, wherein the total amount of the partial ester (2) and the ester (3) is 100 parts by weight of the polycarbonate resin. 0.02 to 0.16 parts by weight.

The polycarbonate resin of the present invention is a homo-, co-polycarbonate resin obtained by reacting a dihydric phenol with a carbonate precursor such as phosgene or diphenyl carbonate, further branched, and a long-chain alkyl group is introduced into a terminal. Those having an average molecular weight of about 12,000 to 30,000 such as those obtained by grafting styrene or the like to a modified polycarbonate resin obtained using bisphenol or vinylphenol having a carbon-carbon unsaturated double bond as a comonomer or a terminal stopper. Terephthalic acid chloride as a part of phosgene, isophthalic acid chloride having a partly ester bond, or a polystyrene modified resin obtained by using a phenolic hydroxyl group or the like as a comonomer grafted with a polycarbonate resin. But can be used It is exemplified as such.

Here, as the dihydric phenol, 2,2-bis (4-
Hydroxyphenyl) propane (= bisphenol A), bis (4-hydroxyphenyl) methane, 1,2-
Bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4-
(Hydroxyphenyl) -1-phenylmethane, 1,1-bis (4-hydroxyphenyl-1,1-diphenyl) methane, 1,1-bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl) ether, Examples include bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, and those obtained by substituting a lower alkyl group or a halogen atom for these phenyl groups, and bisphenol A is the most representative.

The phosphorous acid of (1) of the present invention to be blended with the above polycarbonate resin is intended to suppress the heat resistance of the resin, particularly the decrease in molecular weight at the time of molding, and to promote the decomposition of polycarbonate even under a high temperature and high humidity environment. There is no. This is different from the fact that when a phosphite is used, its decomposition product accelerates the decomposition of the polycarbonate.

The addition amount of the phosphorous acid (1) is preferably 0.0005 to 0.01 parts by weight, particularly 0.001 to 0.005 parts by weight, based on 100 parts by weight of the polycarbonate resin. Conversely, use in more than one part promotes decomposition.

Examples of the method of adding the phosphorous acid (1) include a method of mixing and extruding a powder with a polycarbonate resin, and a method of adding and extruding an aqueous solution to the polycarbonate resin.

The additive components (2) and (3) of the present invention are release agents that improve the releasability at the time of injection molding and improve the transfer of fine irregularities in the mold.

First, a partial ester of a saturated fatty acid having 10 to 22 carbon atoms and a polyhydric alcohol as the component (2) is obtained by mixing a saturated fatty acid such as capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and behenic acid with ethylene glycol Propylene glycol, polyethylene glycol, polypropylene glycol, glycerin, trimethylolpropane, pentaerythritol, partial esters with polyhydric alcohols such as sorbitol, sorbitan monostearate, polyethylene glycol monostearate, glycerin monostearate, glycerin monobe Henate, pentaerythritol monolaurate, pentaerythritol monostearate, and the like are listed as those which can be easily obtained as commercial products. The addition amount is 0.001 to 0.01 parts by weight, and more preferably 0.1 to 0.01 parts by weight, based on 100 parts by weight of the polycarbonate resin.
005-0.01 parts by weight are preferred.

Next, the ester of a saturated fatty acid having 10 to 30 carbon atoms and a monohydric or polyhydric alcohol having 30 or less carbon atoms as the component (3) is a full ester having no alcoholic hydroxyl group. These fatty acid esters are known as ester waxes contained in natural products such as plants, animals, insects, and minerals, including synthetic products. Specifically, butyl stearate, stearyl stearate, and behenyl Synthetic products such as behenate, methyl laurate, isopropyl palmitate, 2-ethylhexyl stearate, pentaerythritol tetrastearate, pentaerythritol tetrabehenate, and long-chain fatty acid esters as main components, and high purity of the components. And beeswax. The addition amount is preferably 0.005 to 0.2 parts by weight, particularly preferably 0.01 to 0.15 parts by weight, based on 100 parts by weight of the polycarbonate resin.

Further, the total amount of the release agent components (2) and (3) added is 0.02 to 0.1 with respect to 100 parts by weight of the polycarbonate resin.
The range of 6 parts by weight is preferable from the viewpoint of the balance between the releasability and the stability.

〔Example〕

 Hereinafter, the present invention will be described with reference to examples and the like.

The percentages and parts in Examples and the like are based on weight unless otherwise specified, and the measuring method was as follows.

Measurement of release force. 7.8 oz. Injection molding machine (Mitsubishi Heavy Industries, Ltd.)
515-150 MST), cup shape at resin temperature 280 ℃, mold temperature 80 ℃ (bottom inner diameter 60mm, top inner diameter 70mm, depth)
A molded product having a thickness of 70 mm and a thickness of 3 mm) is molded at a mold inner pressure of 800 to 805 kg / cm ² , and the resistance value when the molded product is released from the mold is read by a pressure sensor attached to a protruding pin.

Measurement of molecular weight change. The pellet is dried at 120 ° C. for 4 hours, and about 2 g is placed in a test tube and heated at 370 ° C. for 20 minutes under a stream of N ₂ . The change in molecular weight before and after heating can be measured with a flow tester (manufactured by Shimadzu Corporation, temperature 280).
° C, load: 160 kg / cm ² , orifice: 1 mmΦ × 10 mmL) and used as a measure of molecular weight change.

The change in molecular weight is smaller as the change in Q value before and after heating is smaller, and the thermal stability is better.

Appearance and long-term moisture resistance test. Pellet 3.0 oz injection molding machine (Sumitomo Heavy Industries, Ltd.)
Resin temperature 320 ° C, mold temperature
A disc having a thickness of 1.2 mm and a diameter of 130 mm is formed at 105 ° C, and the disc is visually observed for hue, burn, flow mark, and occurrence of silveriness (appearance).

The disc was placed in an environmental tester at 80 ° C. and 90% RH and aged for 500 hours, and the number of white spots of 50 μm or more generated in the disc was read with an optical microscope.

Examples 1 to 7 and Comparative Examples 1 to 8 Phosgene was introduced while stirring a sodium hydroxide aqueous solution of bisphenol A and methylene chloride (= MC) at 20 ° C. Next, p-tert-butylphenol and triethylamine were added, and the mixture was reacted for 1 hour with vigorous stirring. A methylene chloride solution of the reaction product mixture was separated and washed repeatedly with water.

To 100 parts by volume of this solution, 25 parts by volume of n-heptane (= nH) was added and mixed, and the mixed solution was dropped into warm water.
The temperature was raised to ° C. and the solvent was distilled off to obtain a slurry-like polycarbonate powder.

The powder was taken out by filtration and dried at 120 ° C. for 8 hours to obtain a polycarbonate having a viscosity average molecular weight of 15,000.

The additives listed in Table 1 were mixed with the polycarbonate powder and extruded at a resin temperature of 250 to 270 ° C. to obtain a molding material.

Table 1 shows the results of measurement of release resistance, measurement of molecular weight change, appearance and long-term moisture resistance test using the above pellets.

[Functions and Effects of the Invention] As described above, the molding material for polycarbonate resin optical of the present invention has less occurrence of burning even when molded at 300 to 380 ° C, and has an optical property obtained from being extremely excellent in mold release properties. The molded product for use is a product obtained by accurately transferring the surface of a mold and has very small optical distortion. Further, even when it is necessary to use the composition in a high-temperature and high-humidity environment, a decrease in molecular weight due to hydrolysis is small, and the generation of white spots, which is a very serious problem as an optical molded product, is small.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Kazuyuki Akahori 2-12-12, Kanshu-cho, Toyonaka-shi, Osaka Mitsubishi Gas Chemical Co., Ltd. Osaka Plant (56) References JP-A-61-287954 (JP, A) Sho 61-16961 (JP, A) Special table Sho 61-500667 (JP, A)

Claims (2)

(57) [Claims] (1) 10005 parts by weight of a polycarbonate resin having a viscosity average molecular weight of 12,000 to 23,000, and
0.01 parts by weight, (2) 0.001 to 0.01 parts by weight of a partial ester of a saturated fatty acid having 10 to 22 carbon atoms and a polyhydric alcohol, and (3) monovalent or a saturated fatty acid having 10 to 30 carbon atoms and 30 or less carbon atoms An optical molding material containing 0.005 to 0.2 parts by weight of an ester with a polyhydric alcohol. 2. The optical molding material according to claim 1, wherein the total amount of the partial ester (2) and the ester (3) is 0.02 to 0.16 parts by weight per 100 parts by weight of the polycarbonate resin.