JP5429953B2 - Polycarbonate resin composition and molded article comprising the same - Google Patents

Description

  The present invention relates to a polycarbonate resin composition in which fluidity and transparency are improved by blending a cyclic poly (alkylene terephthalate) oligomer and polycaprolactone with a polycarbonate resin, and a molded article comprising the same.

  Polycarbonate resin is a thermoplastic resin excellent in impact resistance, transparency, heat resistance, thermal stability and the like, and is widely used in fields such as electricity, electronics, ITE, machinery, and automobiles. On the other hand, in addition to these excellent performances of the resin, in each of the aforementioned fields, a material having a high fluidity (moldability) is required in order to satisfy the design and design requirements. In particular, in recent years, the trend of weight reduction of products has been remarkable, and the actual situation is that the demand for improvement in fluidity of polycarbonate resins has become more prominent.

On the other hand, as techniques for improving the fluidity of the polycarbonate resin, various techniques have been proposed since the past, but all have advantages and disadvantages, and satisfactory materials are not necessarily proposed.
JP 2001-226576 A JP 2000-319497 A JP 2000-103951 A

  As described above, as a general method for improving the fluidity of the polycarbonate resin, a technique of blending a low molecular weight compound such as a low molecular plasticizer or a good fluidity polymer has been proposed. There is a problem that any one or more of the above-described excellent characteristics of the polycarbonate resin is greatly impaired, and there has been a strong demand for improvement thereof.

  As a result of intensive studies in view of such problems, the present inventors have formulated a polycarbonate resin by blending a specific amount of a specific cyclic poly (alkylene terephthalate) oligomer and polycaprolactone in the polycarbonate resin composition. The present inventors have succeeded in remarkably improving the fluidity and transparency of the present invention and achieved the present invention.

That is, the present invention comprises 100 parts by weight of a polycarbonate resin (A), 0.5 to 6 parts by weight of a cyclic poly (alkylene terephthalate) oligomer (B) and 0.5 to 1 part by weight of polycaprolactone (C). And a molded article comprising the polycarbonate resin composition.

  The present invention is a technology that can remarkably improve the fluidity and transparency while maintaining the performance such as the excellent impact strength, heat resistance, and thermal stability inherent in the polycarbonate resin. It can be suitably used as a housing and parts for products in various fields such as electrical machinery, electronics, and ITE, and has an extremely high industrial utility value.

  The polycarbonate resin (A) used in the present invention is obtained by a phosgene method in which various dihydroxydiaryl compounds and phosgene are reacted, or a transesterification method in which a dihydroxydiaryl compound and a carbonate such as diphenyl carbonate are reacted. A typical example of the polymer is a polycarbonate resin produced from 2,2-bis (4-hydroxyphenyl) propane (bisphenol A).

  Examples of the dihydroxydiaryl compound include bisphenol 4-, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2, 2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3) -Tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis ( Bis (hydroxyaryl) alkanes such as 4-hydroxy-3,5-dichlorophenyl) propane, 1,1- (4-hydroxyphenyl) cyclopentane, bis (hydroxyaryl) cycloalkanes such as 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3 Dihydroxy diaryl ethers such as 3,3'-dimethyldiphenyl ether, dihydroxy diaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3 ' Dihydroxy diaryl sulfoxides such as dimethyldiphenyl sulfoxide, dihydroxy diary such as 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone Sulfone, and the like. These are used individually or in mixture of 2 or more types. In addition to these, piperazine, dipiperidyl hydroquinone, resorcin, 4,4'-dihydroxydiphenyl, and the like may be mixed and used.

  Furthermore, the above dihydroxyaryl compound and a trivalent or higher phenol compound as shown below may be used in combination. Trihydric or higher phenols include phloroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptene, 2,4,6-dimethyl-2,4,6-tri- (4 -Hydroxyphenyl) -heptane, 1,3,5-tri- (4-hydroxyphenyl) -benzol, 1,1,1-tri- (4-hydroxyphenyl) -ethane and 2,2-bis- [4 4- (4,4'-dihydroxydiphenyl) -cyclohexyl] -propane and the like.

  The viscosity average molecular weight of the polycarbonate resin (A) is usually 10,000 to 100,000, preferably 15,000 to 35,000, and more preferably 17,000 to 28,000. In producing such a polycarbonate resin, a molecular weight regulator, a catalyst and the like can be used as necessary.

  The cyclic poly (alkylene terephthalate) oligomer (B) used in the present invention refers to one having a structural unit represented by the following general formula.

  In the formula, R represents an alkylene group having 2 to 8 carbon atoms, and Ar represents a divalent aromatic group. In particular, those in which R is ethylene or tetramethylene and Ar is m-phenylene or p-phenylene are preferably used.

  The cyclic poly (alkylene terephthalate) oligomer (B) is usually a mixture of cyclic oligomers having a polymerization degree of 2 to 30 and the main component having a polymerization degree of up to 12. Commercially available products include CBT manufactured by Cyclix Corporation.

  The compounding quantity of cyclic poly (alkylene terephthalate) oligomer (B) is 0.5-6 weight part with respect to 100 weight part of polycarbonate resin (A). If the blending amount is less than 0.5 parts by weight, the effect of improving the fluidity is small, and if it exceeds 6 parts by weight, the amount of gas generation increases during molding, mold fouling occurs, and the appearance of the molded product is reduced, which is preferable. Absent. More preferably, it is in the range of 3 to 5 parts by weight.

  The polycaprolactone (C) used in the present invention is a polymer produced by ring-opening polymerization of ε-caprolactone in the presence of a catalyst, and in particular, a homopolymer of 2-oxepanone is preferably used. The polymer is easily available as a commercial product, and a tone polymer manufactured by Dow Chemical Company, CAPA manufactured by Solvay Company, and the like are used. The viscosity average molecular weight of the polycaprolactone (C) is preferably 10,000 to 100,000, more preferably 40,000 to 90,000.

  In addition, polycaprolactone (C) may be modified with ε-caprolactone by ring-opening polymerization in the presence of 1,4-butanediol or the like, or a modified polycaprolactone substituted with an ether or ester group at the molecular end. Is also included.

The compounding quantity of polycaprolactone (C) is 0.3-3 weight part with respect to 100 weight part of polycarbonate resin (A). If the blending amount is less than 0.3 parts by weight, the effect of improving the transparency is small, and if it exceeds 3 parts by weight, an extreme decrease in heat resistance occurs, and the pellets are fixed in the pre-drying step before the molding process, and blocking occurs. That is not preferable. More preferably, it is the range of 0.5-1 weight part.

  In the polycarbonate resin composition of the present invention, various known additives, polymers, and the like can be added as necessary depending on the performance required for practical use. For example, in order to suppress discoloration of resin molded products when exposed to light for a long period of time, a hindered amine light-resistant stabilizer, a benzotriazole-based, benzophenone-based, triazine-based, and malonate-based UV absorber and a combination thereof are used. May be added.

  When flame retardancy is required, various known flame retardants, for example, brominated flame retardants such as tetrabromobisphenol A oligomers, monophosphate esters such as triphenyl phosphate and tricresyl phosphate, bisphenol A diesters, etc. In order to further improve the flame retardancy, phosphorous flame retardants such as phosphate-type condensed phosphates such as phosphate, resorcin diphosphate, tetraxylenyl resorcin diphosphate, ammonium polyphosphate and red phosphorus, various silicone flame retardants And metal salts of aromatic sulfonic acid and perfluoroalkanesulfonic acid, preferably 4-methyl-N- (4-methylphenyl) sulfonyl-benzenesulfonamide potassium salt, diphenylsulfone- 3- potassium sulfonate, Potassium phenyl sulfonic -3-3'- disulfonic acid, sodium para-toluene sulfonic acid, also organic metal salts such as potassium perfluorobutane sulfonate and the like may be added. Among these flame retardants, phosphorus-based flame retardants can be suitably used because they can improve not only flame retardancy but also fluidity.

  In the polycarbonate resin composition of the present invention, known additives other than those described above, for example, phenol-based or phosphorus-based heat stabilizer [2,6-di-t-butyl-4-methylphenol, 2- (1-methyl Cyclohexyl) -4,6-dimethylphenol, 4,4'-thiobis- (6-tert-butyl-3-methylphenol), 2,2-methylenebis- (4-ethyl-6-tert-methylphenol), n -Octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, tris (2,4-di-t-butylphenyl) phosphite, 4,4'-biphenylenediphosphinic acid tetrakis- ( 2,4-di-t-butylphenyl), etc.], lubricant [paraffin wax, n-butyl stearate, synthetic beeswax, natural beeswax, glycerin monoester, Tantalate wax, polyethylene wax, pentaerythritol tetrastearate, etc.], colorant [eg titanium oxide, carbon black, dye], filler [calcium carbonate, clay, silica, glass fiber, glass sphere, glass flake, carbon fiber, Talc, mica, various whiskers, etc.], fluidity improvers, spreading agents [epoxidized soybean oil, liquid paraffin, etc.], other thermoplastic resins and various impact resistance improvers (polybutadiene, polyacrylate, A rubber reinforced resin obtained by graft polymerization of a compound such as methacrylic acid ester, styrene, acrylonitrile, etc. to a rubber such as an ethylene / propylene rubber may be added as necessary.

  There is no restriction | limiting in the embodiment and order in this invention. For example, a polycarbonate resin (A), a cyclic poly (alkylene terephthalate) oligomer (B) and a polycaprolactone (C) are weighed in arbitrary blending amounts and mixed together with a tumbler, riboblender, high-speed mixer, etc. A method of melt-kneading and pelletizing using a single-screw or twin-screw extruder, or a method of measuring each or a part of each component separately, putting them into a extruder from a plurality of feeders, and melt-mixing them Further, (B) and / or (C) is blended in a high concentration in (A), and once melt-mixed and pelletized to obtain a master batch, the master batch and (A) are mixed in a desired ratio. Can also be mixed. Then, when these components are melt-mixed, arbitrary conditions such as the position at which the extruder is introduced, the extrusion temperature, the screw rotation speed, the supply amount, and the like can be selected and pelletized. Further, the master batch and (A) can be mixed by dry mixing at a desired ratio, and then directly fed into an injection molding apparatus or a sheet extruder apparatus to form a molded product.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples, unless the summary is exceeded. Unless otherwise specified, “%” and “part” in the examples are based on weight standards.

In addition, the various compounding components used are as follows.
Polycarbonate resin:
Sumitomo Dow Caliber 200-20
(Viscosity average molecular weight: 18500, hereinafter abbreviated as PC)
Cyclic poly (butylene terephthalate) oligomer:
CBT made by Cyclix Corporation
(Melting point: 140 to 190 ° C., hereinafter abbreviated as CBT)
Polycaprolactone:
Tone polymer P-787 manufactured by Dow Chemical Company
(Viscosity average molecular weight: 80000, hereinafter abbreviated as PCL)

  The above-mentioned various raw materials are collectively put into a tumbler at the blending ratios shown in Tables 1-2, and after dry mixing for 10 minutes, using a twin screw extruder (KTX37 manufactured by Kobe Steel), the melting temperature is 280 ° C. And kneaded to obtain pellets of the polycarbonate resin composition. Various test pieces were processed from the obtained pellets using a J100E-C5 injection molding machine manufactured by Nippon Steel Works, and various data were collected by the following methods.

(Archimedes spiral flow fluidity)
The flow length at a channel thickness of 1 mm was measured using an Archimedes spiral flow mold under the conditions of a melting temperature of 280 ° C. and an injection pressure of 1600 kg / cm ² . A flow length of 125 mm or more was regarded as acceptable.

(Izod impact strength)
A specimen for an Izod impact test was processed under the condition of a melting temperature of 280 ° C., and the Izod impact strength was measured in accordance with ASTM D256. The measurement temperature is 23 ° C., and the thickness of the test piece is 3.2 mm. An impact value of 40 kg / cm / cm or more was considered acceptable.

(transparency)
A test piece having a thickness of 2 mm was molded under the condition of a melting temperature of 280 ° C., and the light transmittance was measured using CMS-35SP manufactured by JASCO Corporation.

  As shown in Table 1, when the polycarbonate resin composition satisfied the constituent requirements of the present invention (Examples 1 to 5), the standard was satisfied over all evaluation items.

As shown in Table 2, when the polycarbonate resin composition did not satisfy the constituent requirements of the present invention, each case had some drawbacks.
In Comparative Example 1, the amount of CBT was less than the lower limit of the specified range, and the fluidity and transparency were inferior.
In Comparative Example 2, the CBT content was greater than the upper limit of the specified range, and the impact strength and transparency were inferior.
In Comparative Example 3, the amount of PCL was less than the lower limit of the specified range, and the transparency was poor.
In Comparative Example 4, the amount of PCL was more than the upper limit of the specified range, and the impact strength was inferior.

Claims (3)

A polycarbonate resin composition comprising 100 parts by weight of a polycarbonate resin (A), 0.5 to 6 parts by weight of a cyclic poly (alkylene terephthalate) oligomer (B) and 0.5 to 1 part by weight of polycaprolactone (C). .   The polycarbonate resin composition according to claim 1, wherein the cyclic poly (alkylene terephthalate) oligomer is a cyclic poly (butylene terephthalate) oligomer.   A molded article formed by molding the polycarbonate resin composition according to claim 1 or 2.