JP2008544062A - Polycarbonate resin composition with excellent chemical resistance and fluidity - Google Patents

Abstract

The polycarbonate resin composition having excellent chemical resistance and fluidity according to the present invention includes (A) 80-98.5 parts by weight of polycarbonate resin, (B) 0.5-10 parts by weight of syndiotactic polystyrene resin, (C) 1-30 parts by weight of a core-shell graft copolymer and (D) 0.01-10 parts by weight of a phosphate compound.

Description

  The present invention relates to a polycarbonate resin composition. More specifically, the present invention introduces syndiotactic polystyrene, a core-shell graft copolymer and a phosphate ester compound into a polycarbonate resin at the same time, thereby improving impact resistance while being excellent in chemical resistance and fluidity. The present invention relates to a polycarbonate resin composition having good properties.

  Polycarbonate resins are widely used as engineering plastics due to superior impact resistance, flame retardancy, dimensional stability, high heat resistance, and the like compared to other resins. In particular, the use of polycarbonate resin is rapidly expanding to portable electronic devices that require excellent impact resistance in various environments such as mobile phones. In the aspect of mobile phone design, the painting process is intensifying.

  Such enhancement of the coating process is progressing in the direction of adding a coating process to an existing unpainted exterior material or increasing the thickness of the coating film in order to enhance the coating effect. If a coating process is added or the coating thickness is increased, the resin will be exposed to a paint dilution solution or paint thinner, which allows the diluent solvent to penetrate the resin and be used as an exterior material. As a result, the mechanical properties of the resulting resin will be reduced. In general, polycarbonate resins as amorphous polymers are not as good as crystalline polymers in resistance to solvents used in paint diluents. For these reasons, it is disadvantageous to use a polycarbonate resin as an exterior material for various products including portable electronic devices.

  A lot of research has been done to improve the chemical resistance of polycarbonate. Research to improve chemical resistance has focused on methods of mixing polycarbonate resins with polymers that are relatively slow to penetrate chemicals. However, by adopting such a method, the chemical resistance of the polycarbonate resin can be improved, but the impact resistance and fatigue resistance of the polycarbonate resin may be lowered by the addition of other polymers. As a result, there is a great need to improve polycarbonate resins for use in portable electronic devices.

  Accordingly, as a result of researches, the inventors have found that when a syndiotactic polystyrene polymer resin, a core-shell graft copolymer, and a phosphate ester compound are introduced into a polycarbonate resin, the polycarbonate resin has excellent impact resistance and fatigue resistance. It has been found that the chemical resistance and fluidity can be improved while retaining the properties. Accordingly, the present inventors have developed a polycarbonate resin composition having excellent impact resistance while being excellent in chemical resistance and fluidity based on the above discovery.

An object of the present invention is to provide a polycarbonate resin composition having excellent chemical resistance.
Another object of the present invention is to provide a polycarbonate resin composition having excellent chemical resistance and impact resistance.

Another object of the present invention is to provide a polycarbonate resin composition having excellent fluidity and impact resistance.
Another object of the present invention is to provide a polycarbonate resin composition having excellent fatigue resistance.

  The above and other objects of the present invention can all be achieved by the present invention described below.

  The polycarbonate resin composition according to the present invention comprises (A) 80-98.5 parts by weight of polycarbonate resin, (B) 0.5-10 parts by weight of syndiotactic polystyrene resin, (C) core-shell graft copolymer 1 And 30 parts by weight and (D) 0.1 to 10 parts by weight of a phosphoric ester compound.

  The polycarbonate resin, syndiotactic polystyrene resin, core-shell graft copolymer and phosphate ester compound used in the polycarbonate resin composition according to the present invention will be described in detail below.

(A) Polycarbonate resin The polycarbonate resin used in the resin composition of the present invention is produced by reacting dehydric phenol with phosgene in the presence of a molecular weight regulator and a catalyst, or dehydric phenol and diphenyl carbonate. It can manufacture using ester interchange reaction of a carbonate precursor like. Examples of the polycarbonate resin may include a linear polycarbonate, a branched polycarbonate, a polyester carbonate copolymer, and the like.

  The dehydric phenol may be one of bisphenols, and a preferred bisphenol is 2,2-bis (4-hydroxyphenyl) propane (bisphenol A). Bisphenol A may be partially or wholly replaced with other dehydric phenols. Dehydric phenols other than bisphenol A include hydroquinone, 4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (3 , 5-dimethyl-4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) ketone, bis ( 4-hydroxyphenyl) ether and halogenated bisphenols such as 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane.

The polycarbonate resin (A) may be a single polymer, a copolymer using two or more dehydric phenols, or a mixture thereof.
An example of the linear polycarbonate resin is bisphenol A polycarbonate resin. The branched polycarbonate can be produced by reacting a polyfunctional aromatic compound such as trimellitic anhydride or trimellitic acid with dehydroxyphenol and a carbonate precursor. The polyester carbonate can be produced by reacting a difunctional carboxylic acid with a dehydric phenol and a carbonate precursor.

  According to the present invention, the content of the polycarbonate resin (A) is 80 to 98.5 parts by weight. If the polycarbonate resin (A) is used in an amount of less than 80 parts by weight, the impact resistance may be lowered.

(B) Syndiotactic polystyrene resin Generally, a polystyrene resin is divided into three different structures of atactic, isotactic and syndiotactic depending on the position of the benzene ring in the side chain. The atactic polystyrene has an irregular arrangement of the benzene rings, and the isotactic polystyrene has a structure in which the benzene rings are regularly arranged on one side of the main chain. On the other hand, syndiotactic polystyrene has a structure in which benzene rings are alternately and regularly arranged.

  The syndiotactic polystyrene can be produced by polymerizing one or more styrene monomers in the presence of a catalyst system comprising a metallocene catalyst and a cocatalyst. In the metallocene catalyst, one or two cycloalkanedienyl groups (cyclopentadienyl group, indenyl group, fluorenyl group and derivatives thereof) are group IV transition metal complexes of the periodic table such as Ti, Zr, and Hf. Is combined with.

  A method for polymerizing styrene monomers is disclosed in US Pat. No. 6,010,974. The patent uses a metallocene catalyst including an alkyl-bridged binuclear metallocene catalyst, a silyl-bridged binuclear metallocene catalyst and an alkyl-silyl bridged binuclear metallocene catalyst, and has high stereoregularity, high melting point and excellent molecular weight distribution. It is possible to produce a polystyrene resin having the same.

On the other hand, US Pat. No. 6,284,700 discloses syndiotactic polystyrene using a catalyst system comprising a metallocene catalyst and a cocatalyst.
In the present invention, it is preferable to use a syndiotactic polystyrene resin having a syndiotactic degree of greater than 97%. When the syndiotactic degree is less than 97%, chemical resistance may be lowered.

  In the polycarbonate resin composition according to the present invention, the content of the syndiotactic polystyrene resin (B) is 0.5 to 10 parts by weight. If it is used in an amount of less than 0.5 parts by weight, the chemical resistance may be lowered, and if it is used in an amount of more than 10 parts by weight, the impact resistance may be lowered.

(C) Core-shell graft copolymer The core-shell graft copolymer (C) used in the present invention forms a hard shell by grafting a vinyl monomer onto a resin core structure.

The core-shell structure of the core-shell graft copolymer (C) is obtained by polymerizing one or more rubbers selected from the group consisting of diene rubbers, acrylate rubbers, and silicone rubbers having 4 to 6 carbon atoms. Te after producing the rubber core, graftable C ₁ -C ₈ alkyl methacrylates, C ₁ -C ₈ acrylic acid alkyl esters, maleic anhydride, and C ₁ -C ₄ as an alkyl or phenyl nucleus-substituted maleimide One or more unsaturated compounds are grafted onto the rubber core. The rubber content is preferably 50 to 90 parts by weight with respect to 100 parts by weight of the core-shell graft copolymer (C).

  The acrylate rubber is formed using acrylate monomers such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, hexyl methacrylate, and 2-ethylhexyl methacrylate. At this time, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, allyl methacrylate, triallyl cyanurate, or the like may be added as a curing agent.

The silicone rubber may be manufactured from cyclosiloxane. Examples of the cyclosiloxane include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxane, tetramethyltetraphenylcyclotetrosiloxane, octaphenylcyclo Examples include tetrasiloxane. The silicone rubber may be produced from one or more of these siloxanes. At this time, trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, or the like may be used as a curing agent.

  Among the rubbers, it is preferable to use silicone rubber or a mixture of silicone rubber and acrylate rubber from the viewpoint of chemical resistance and thermal stability based on structural stability. Furthermore, it is preferable that the average particle diameter of the rubber is 0.4 to 1 μm because it generally has excellent impact resistance and colorability.

C ₁ -C ₈ methacrylic acid alkyl ester or C ₁ as methacrylic acid ester
-C ₈ acrylic acid alkyl ester is a monohydric alcohol having 1 to 8 carbon atoms. Examples of these include methacrylic acid methyl ester, methacrylic acid ethyl ester or methacrylic acid propyl ester. Of these, methacrylic acid methyl ester is most preferred.

  The polycarbonate resin composition according to the present invention comprises (A) a polycarbonate resin, (B) a syndiotactic polystyrene resin, (C) a core-shell graft copolymer, and (D) a phosphoric ester compound. 1 to 30 parts by weight, preferably 1 to 10 parts by weight, of the core-shell graft copolymer. If it is used in an amount of less than 1 part by weight, the effect of impact reinforcement may not be sufficient. If it is used in excess of 30 parts by weight, the tensile strength, flexural strength and flexural modulus may be lowered.

(D) Phosphate ester compound The phosphate ester compound (D) or a mixture thereof used in the polycarbonate resin composition of the present invention can be represented by the following chemical formula (I):

In the formula (I), R ₁ , R ₂ , R ₄ and R ₅ are each independently C _6-20 aryl or an alkyl-substituted C _6-20 aryl group; R ₃ is C _{6- 30} aryl or alkyl-substituted C _6-30 aryl group derivatives; and l has an average value of 0 to 3 as the number average degree of polymerization.

R ₁ , R ₂ , R ₄ and R ₅ are preferably phenyl groups or phenyl groups substituted with alkyl groups such as methyl, ethyl, isopropyl, t-butyl, isobutyl, isoamyl or t-amyl and the like. . Of these, a phenyl group substituted with a methyl, ethyl, isopropyl or t-butyl group is most preferred.

Compounds of Formula used in the production of the resin composition (I) of the present invention is a C _6-30 aryl or alkyl-substituted C _6-30 aryl oligomeric phosphoric acid ester compound derived from the base. Preferred C _6-30 aryl or alkyl substituted C _6-30 aryl groups are groups derived from resorcinol, hydroquinone or bisphenol-A.

  The phosphate ester compound is an aryl-substituted phosphate ester having an average value of l of 0 to 3. A single phosphate ester compound having a value of l of 0, 1, 2, and 3 may be used alone. A mixture of two or more of the above-mentioned phosphate esters may be used, and this mixture is produced by a polymerization process, or a mixture of a plurality of phosphate ester compounds having different l values.

  In the polycarbonate resin composition according to the present invention, 100 weights of the composition comprising (A) a polycarbonate resin, (B) a syndiotactic polystyrene resin, (C) a core-shell graft copolymer and (D) a phosphate ester compound. The phosphoric acid ester compound (D) can be used in an amount of 0.01 to 10 parts by weight, preferably 0.1 to 7 parts by weight, based on parts. If it is used in an amount of less than 0.01 parts by weight, there may be only a slight effect of improving chemical resistance and fluidity. If it is used in excess of 10 parts by weight, impact strength, tensile strength, flexural strength, flexural modulus, etc. There is a case where the mechanical strength of the material decreases.

  You may add another additive to the resin composition of this invention. In particular, when an inorganic filler such as glass fiber, carbon fiber, talc, silica, mica, and alumina is added, mechanical strength, heat distortion temperature, and the like may be improved. Furthermore, in the production of the resin composition of the present invention, substances such as ultraviolet absorbers, heat stabilizers, antioxidants, flame retardants, lubricants, dyes or pigments may be added.

Regarding the physical properties of the resin composition of the present invention, the 1/8 "Izod impact strength and the 1/4" Izod impact strength measured by ASTM D256 are preferably greater than 70 and 50 kg · cm / cm, respectively.

  The chemical resistance can be measured by the falling ball impact strength before and after being immersed in the solvent. As a test piece, a 3 mm × 100 mm × 100 mm panel block made of a polycarbonate resin composition was immersed in a coating thinner for 1 minute and dried at 80 ° C. for 30 minutes. Subsequently, a falling ball impact test was performed on this specimen, and the load of the falling ball at a constant displacement was measured and compared with the load of the specimen before the solvent immersion. It is preferable that the falling ball impact strength before immersion in the solvent is greater than 1,000 N, the falling ball impact strength after immersion in the solvent is greater than 800 N, and the brittle fracture rate after immersion in the solvent is less than 25%. A variety of paint thinners may be used alone or as a mixture with other solvents. Examples of the paint thinner include alcohol and ketone.

  The fluidity is confirmed by measuring the length of the resin pellet after injecting a 1 mm thick resin pellet through an injection machine under conditions of a resin temperature of 260 to 330 ° C. and a mold temperature of 60 to 100 ° C. be able to. The length of the resin pellet is also called 'injection flow length', and it is preferable that the value of this injection flow length is larger than 90 mm.

  The resin composition of the present invention can be produced using a known method. For example, the pellet can be produced by melting the resin composition mixed with the other additive and then extruding it through an extruder.

The composition of the present invention can be used for the molding of products, and is particularly suitable for the production of electrical and electronic products such as housings for TVs, computers, mobile phones and office automation equipment.
The present invention can be further embodied in the following examples. The following examples are for illustrative purposes only and are not intended to limit or limit the protection scope of the present invention.

  Details of (A) polycarbonate resin, (B) syndiotactic polystyrene resin, (C) core-shell graft copolymer, (D) phosphate ester compound used in Examples and Comparative Examples of the present invention are as follows. Street.

(A) Polycarbonate resin As a bisphenol-A type linear polycarbonate having a weight average molecular weight of 25,000 g / mol, PANLITE L-1250WP manufactured by TEIJIN was used.

(B) Syndiotactic polystyrene resin Syndiotactic polystyrene XARECS100 of Nippon Idemitsu Co., Ltd. having a melting point of 250 ° C., a glass transition temperature of 100 ° C. and a specific gravity of 1.01 was used.

(C) Core-shell graft copolymer (c ₁ ) Core obtained by grafting methacrylic acid methyl ester monomer with 20 to 30 parts by weight to 70 to 80 parts by weight of butadiene rubber having a weight average particle diameter of about 0.1 μm - a shell graft copolymer Japan Kureha (KUREHA) Co. Paraloid (PALALOID) EXL-2602; and (c ₂₎ the weight average particle diameter of about 0.5μm dimethylsiloxane 5
Of Mitsubishi Rayon Co., Ltd., a core-shell graft copolymer in which a methyl methacrylate monomer is grafted with 30 to 40 parts by weight of a rubber composed of 70 parts by weight and 30 to 95 parts by weight of butyl acrylate. Metallen S2100 was used as an impact reinforcement.

(D) Phosphate ester compound (d ₁ ) In the above chemical formula (I), l = 1, and R ₁ , R ₂ , R ₄ and R ₅ are 2, 6
Using resorcinol-di (bis-2,6-dimethylphenyl) phosphate (Daihachi PX-200), which is a dimethylphenyl group and R ₃ is a moiety derived from resorcinol; (D ₂ ) Triphenyl phosphate (TPP of Daihachi Co., Ltd.) in which l = 0 in the chemical formula (I) and R ₁ , R ₂ , R ₄ , and R ₅ are phenyl groups was used.

[Examples 1-7 and Comparative Examples 1-11]
The above components were mixed according to the composition ratios shown in Tables 1 and 2 below, and manufactured into pellets using a twin screw extruder with φ = 45 mm. The produced pellets were dried at 110 ° C. for more than 3 hours, and then injected with a 10 oz injection machine under conditions of a temperature of 260 to 330 ° C. and a mold temperature of 60 to 100 ° C. to produce a panel block. The notched Izod impact strength (1/8 ″, 1/4 ″) of the manufactured specimen was measured according to ASTM D256. Further, in order to evaluate the chemical resistance of the resin composition, a 3 mm × 100 mm × 100 mm panel block was immersed in a coating thinner for 1 minute and dried at 80 ° C. for 30 minutes. The load of the falling ball at a constant displacement was measured and compared with the load before the solvent immersion. Moreover, after confirming the fracture mode, the brittle fracture rate was measured. In order to evaluate the flow performance, a manufactured and dried 1 mm thick spiral block was injected from a 10 oz injection machine under conditions of a temperature of 260 to 330 ° C. and a mold temperature of 60 to 100 ° C., and the injection flow length after injection Was measured.

  From the results shown in Tables 1 and 2, in Examples 1 to 7, when syndiotactic styrene polymer, core-shell graft copolymer, and phosphate compound are used in a certain ratio, Comparative Examples 1 to 11 are used. As in the case of using pure polycarbonate alone, or compared with the case where syndiotactic styrenic polymer, core-shell graft copolymer, and phosphate ester compound are not used in a certain ratio, It can be seen that the chemical resistance and fluidity of the polycarbonate resin are improved while maintaining the properties. In Example 3 and Comparative Example 6, the fluidity is improved when the syndiotactic styrene polymer and the phosphate compound are used at the same time.

  Simple variations or modifications of the present invention can be readily utilized by those having ordinary knowledge in the field. All such modifications and changes are included in the scope of the present invention.

Claims (9)

(A) 80-98.5 parts by weight of polycarbonate resin;
(B) 0.5 to 10 parts by weight of syndiotactic polystyrene resin;
(C) 1-30 parts by weight of a core-shell graft copolymer; and
(D) 0.01 to 10 parts by weight of a phosphoric ester compound;
A polycarbonate resin composition comprising:   The polycarbonate resin composition according to claim 1, wherein the polycarbonate resin (A) is selected from the group consisting of linear polycarbonate, branched polycarbonate, and polyester carbonate copolymer.   The polycarbonate resin composition according to claim 1, wherein the syndiotactic polystyrene resin (B) has a syndiotactic degree of greater than 97%. The core-shell graft copolymer (C) is
Producing a rubber core by polymerizing one or more rubbers selected from the group consisting of C 4-6 diene rubbers, acrylate rubbers, and silicone rubbers;
C ₁ -C ₈ alkyl methacrylates, C ₁ -C ₈ methacrylic acid esters, maleic acid anhydride, and C ₁ -C ₄ alkyl or phenyl nucleus one or more graftable compounds selected from the group consisting of substituted maleimide Is grafted onto the rubber core;
The polycarbonate resin composition according to claim 1, wherein the polycarbonate resin composition has a core-shell structure formed by steps. The polycarbonate resin composition according to claim 1, wherein the phosphate ester compound (D) is represented by the following chemical formula (I):

Wherein R ₁ , R ₂ , R ₄ and R ₅ are each independently a C _6-20 aryl or alkyl-substituted C _6-20 aryl group; R ₃ is a C _6-30 aryl or Alkyl-substituted C _6-30 aryl group derivatives; and the average value of l is 0-3.   6. 1/8 "Izod impact strength measured by ASTM D256 is greater than 70 kg.cm/cm and 1/4" Izod impact strength is greater than 50 kg.cm/cm. The polycarbonate resin composition according to any one of the above.   The falling ball impact strength before solvent immersion is greater than 1,000 N, the falling ball impact strength after solvent immersion is greater than 800 N, and the brittle fracture rate after solvent immersion is 25%. The polycarbonate resin composition according to any one of 5.   When a spiral block is injected to a thickness of 1 mm with a 10 oz injection machine at a temperature of 260 to 330 ° C. and a mold temperature of 60 to 100 ° C., the length of the resin resin injection resin pellet is longer than 90 mm. The polycarbonate resin composition according to any one of claims 1 to 5.   A molded article comprising the polycarbonate resin composition according to any one of claims 1 to 5.