Patent Description:
As engineering plastics, polycarbonate resins have good properties in terms of impact resistance, heat resistance, dimensional stability, weather resistance, flame retardancy, electrical properties, transparency, and are usefully applied to housings of electric/electronic products, interior/exterior materials of office equipment. In addition, various fillers are used to improve various properties of the polycarbonate resins.

However, fillers, such as glass fiber, talc, and wollastonite, which are applied to improve dimensional stability of the polycarbonate resins, have different physical properties depending on the kind of fillers and can cause difficulty in realization of colors due to increase in yellowness index and in realization of metal level dimensional stability due to deterioration in properties when added in a certain amount or more.

Therefore, there is a need for development of a thermoplastic resin composition that can realize metal-level dimensional stability and exhibits good properties in terms of flame retardancy, impact resistance, color.

The background technique of the present invention is disclosed in <CIT>.

<CIT> discloses a flame retardant composition comprising:.

<CIT> discloses a glass-fiber-reinforced polycarbonate resin composition comprising:.

the content of the polydiorganosiloxane derived from the component A-<NUM> in the resin composition being <NUM> to <NUM> wt percent.

<CIT> discloses a thermoplastic resin composition which comprises:.

wherein the polyether-ester copolymer has a melt volume flow rate (MVR) of about <NUM>-<NUM><NUM>/<NUM> as measured under conditions of <NUM> degrees centigrade and <NUM> based on ISO <NUM>. The thermoplastic resin composition is excellent in impact resistance, appearance characteristics, metal joining properties.

It is one object of the present invention to provide a thermoplastic resin composition that exhibits good properties in terms of dimensional stability, flame retardancy, impact resistance, color.

It is another object of the present invention to provide a molded product manufactured from the thermoplastic resin composition.

The above and other objects of the present invention can be achieved by the present invention described below. It is noted that <NUM> kilogram-force centimeter (kgf·cm) equals <NUM> newton centimeter (N·cm) and <NUM>" (inch) equals <NUM>.

The present invention provides a thermoplastic resin composition that has good properties in terms of dimensional stability, flame retardancy, impact resistance, color, and a molded product manufactured therefrom.

A thermoplastic resin composition according to the present invention comprises: (A) a polycarbonate resin; (B) a polyester resin; (C) glass fiber; (D) talc; and (E) a phosphazene flame retardant.

The polycarbonate resin according to one embodiment of the present invention may comprise any polycarbonate resin used in typical thermoplastic resin compositions. For example, the polycarbonate resin may be an aromatic polycarbonate resin prepared by reacting diphenols (aromatic diol compounds) with a precursor, such as phosgene, halogen formate, or carbonate diester.

In some embodiments, the diphenols may comprise, for example, <NUM>,<NUM>'-biphenol, <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)propane, <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>-methylbutane, <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)cyclohexane, <NUM>,<NUM>-bis(<NUM>-chloro-<NUM>-hydroxyphenyl)propane, and <NUM>,<NUM>-bis-(<NUM>,<NUM>-dichloro-<NUM>-hydroxyphenyl)propane, without being limited thereto. For example, the diphenols may be <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)propane, <NUM>,<NUM>-bis(<NUM>,<NUM>-dichloro-<NUM>-hydroxyphenyl)propane, or <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)cyclohexane, specifically <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)propane, which is also referred to as bisphenol-A.

In some embodiments, the polycarbonate resin may be a branched polycarbonate resin. For example, the polycarbonate resin may be a polycarbonate resin prepared by adding a tri- or higher polyfunctional compound, specifically, a trior higher valent phenol group-containing compound, in an amount of about <NUM> mol% to about <NUM> mol% based on the total number of moles of the diphenols used in polymerization.

In some embodiments, the polycarbonate resin may be a homopolycarbonate resin, a copolycarbonate resin, or a blend thereof. In addition, the polycarbonate resin may be partly or completely replaced by an aromatic polyester-carbonate resin obtained by polymerization in the presence of an ester precursor, for example, a bifunctional carboxylic acid.

In some embodiments, the polycarbonate resin may have a weight average molecular weight (Mw) of about <NUM>,<NUM>/mol to about <NUM>,<NUM>/mol, for example, about <NUM>,<NUM>/mol to about <NUM>,<NUM>/mol, as measured by gel permeation chromatography (GPC). Within this range, the thermoplastic resin composition can have good fluidity (processability).

According to the present invention, the polyester resin serves to realize metal-level dimensional stability of the thermoplastic resin composition together with the polycarbonate resin, glass fiber, talc without deterioration in other properties, such as impact resistance, flame retardancy, color, and may be selected from any polyester resins used in a typical thermoplastic resin composition. For example, the polyester resin may be obtained by polycondensation of a dicarboxylic acid component and a diol component, in which the dicarboxylic acid component may comprise: aromatic dicarboxylic acids, such as terephthalic acid (TPA), isophthalic acid (IPA), <NUM>,<NUM>-naphthalene dicarboxylic acid, <NUM>,<NUM>-naphthalene dicarboxylic acid, <NUM>,<NUM>-naphthalene dicarboxylic acid, <NUM>,<NUM>-naphthalene dicarboxylic acid, <NUM>,<NUM>-naphthalene dicarboxylic acid, <NUM>,<NUM>-naphthalene dicarboxylic acid, <NUM>,<NUM>-naphthalene dicarboxylic acid, <NUM>,<NUM>-naphthalene dicarboxylic acid, <NUM>,<NUM>-naphthalenedicarboxylic acid; and aromatic dicarboxylates, such as dimethyl terephthalate (DMT), dimethyl isophthalate, dimethyl-<NUM>,<NUM>-naphthalate, dimethyl-<NUM>,<NUM>-naphthalate, dimethyl-<NUM>,<NUM>-naphthalate, dimethyl-<NUM>,<NUM>-naphthalate, dimethyl-<NUM>,<NUM>-naphthalate, dimethyl-<NUM>,<NUM>-naphthalate, dimethyl-<NUM>,<NUM>-naphthalate, and in which the diol component may comprise ethylene glycol, <NUM>,<NUM>-propylene glycol, <NUM>,<NUM>-propylene glycol, <NUM>,<NUM>-dimethyl-<NUM>,<NUM>-propanediol, <NUM>,<NUM>-butanediol, <NUM>,<NUM>-butanediol, <NUM>,<NUM>-pentanediol, <NUM>,<NUM>-hexanediol, and a cycloalkylene diol.

In some embodiments, the polyester resin may comprise at least one of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), and polycyclohexylene terephthalate. For example, the polyester resin may be polyethylene terephthalate, polybutylene terephthalate, or a combination thereof.

In some embodiments, the polyester resin may have an inherent viscosity of about <NUM> dl/g to about <NUM> dl/g, for example, about <NUM> dl/g to about <NUM> dl/g, as measured in an o-chloro phenol solution (concentration: <NUM>/dl) at <NUM> using an Ubbelohde viscometer (capillary viscometer). Within this range, the thermoplastic resin composition can exhibit good processability, dimensional stability.

In some embodiments, the polyester resin may be present in an amount of about <NUM> parts by weight to about <NUM> parts by weight, for example, about <NUM> part by weight to about <NUM> parts by weight, relative to about <NUM> parts by weight of the polycarbonate resin. If the content of the polyester resin is less than about <NUM> part by weight relative to about <NUM> parts by weight of the polycarbonate resin, the thermoplastic resin composition can suffer from deterioration in dimensional stability, and if the content of the polyester resin exceeds about <NUM> parts by weight, the thermoplastic resin composition can suffer from deterioration in flame retardancy, impact resistance.

According to the present invention, the glass fiber serves to realize metal-level dimensional stability of the thermoplastic resin composition together with the polycarbonate resin, the polyester resin, talc without deterioration in other properties, such as flame retardancy, impact resistance, color.

In some embodiments, the glass fiber may have a rectangular cross-section. The glass fiber having a rectangular cross-section may have a cross-section aspect ratio (long-side length/short-side length in cross-section) of about <NUM> to about <NUM>, for example, about <NUM> to about <NUM>, a short-side length of about <NUM> to about <NUM>, for example, about <NUM> to about <NUM>, and a pre-processing length of about <NUM> to about <NUM>, for example, about <NUM> to about <NUM>, as measured by a scanning electronic microscope (Manufacturer: JEOL, Model: JSM-6390A). Within this range, the thermoplastic resin composition can have good properties in terms of dimensional stability, rigidity, processability.

In some embodiments, the glass fiber may be subjected to surface treatment with a typical surface treatment agent.

In some embodiments, the glass fiber may be present in an amount of about <NUM> parts by weight to about <NUM> parts by weight, for example, about <NUM> parts by weight to about <NUM> parts by weight, relative to about <NUM> parts by weight of the polycarbonate resin. If the content of the glass fiber is less than about <NUM> parts by weight relative to about <NUM> parts by weight of the polycarbonate resin, the thermoplastic resin composition can suffer from deterioration in dimensional stability, and if the content of the glass fiber exceeds about <NUM> parts by weight, the thermoplastic resin composition can suffer from deterioration in impact resistance, flame retardancy.

In some embodiments, the polyester resin (B) and the glass fiber (C) may be present in a weight ratio (B:C) of about <NUM>:<NUM> to about <NUM>:<NUM>, for example, about <NUM>:<NUM> to about <NUM>:<NUM>. Within this range, the thermoplastic resin composition can exhibit good properties in terms of dimensional stability, impact resistance.

According to the present invention, the talc serves to realize metal-level dimensional stability of the thermoplastic resin composition together with the polycarbonate resin, the polyester resin, glass fiber without deterioration in other properties comprising flame retardancy, impact resistance, color.

In some embodiments, the talc may be plate-shaped fillers and may have an average particle diameter (D50) of about <NUM> to about <NUM>, for example, about <NUM> to about <NUM>, as measured by a laser particle analyzer (Manufacturer: Beckman Coulter, Model: LS <NUM><NUM>). If the talc has an average particle diameter outside of this range, the thermoplastic resin composition can suffer from deterioration in dimensional stability, rigidity, processability.

In some embodiments, the talc may be present in an amount of about <NUM> parts by weight to about <NUM> parts by weight, for example, about <NUM> parts by weight to about <NUM> parts by weight, relative to about <NUM> parts by weight of the polycarbonate resin. If the content of the talc is less than about <NUM> parts by weight relative to about <NUM> parts by weight of the polycarbonate resin, the thermoplastic resin composition can suffer from deterioration in dimensional stability, and if the content of the talc exceeds about <NUM> parts by weight, the thermoplastic resin composition can suffer from deterioration in impact resistance, flame retardancy.

In some embodiments, the glass fiber and the talc may be present in a weight ratio (C:D) of about <NUM>:<NUM> to about <NUM>:<NUM>, for example, about <NUM>:<NUM> to about <NUM>:<NUM>. If the weight ratio of the glass fiber to the talc is less than about <NUM>:<NUM>, the thermoplastic resin composition can suffer from deterioration in impact resistance, and if the weight ratio of the glass fiber to the talc exceeds about <NUM>:<NUM>, the thermoplastic resin composition can suffer from deterioration in dimensional stability.

The phosphazene flame retardant according to one embodiment of the present invention serves to improve flame retardancy, impact resistance of the thermoplastic resin composition and may comprise a phosphazene compound used for a typical flame retardant thermoplastic resin composition.

In some embodiments, the phosphazene flame retardant may comprise a phosphazene compound represented by Formula <NUM>. <CHM>
where R<NUM>, R<NUM>, R<NUM>, R<NUM>, R<NUM> and R<NUM> are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted C<NUM> to C<NUM> alkyl group, a substituted or unsubstituted C<NUM> to C<NUM> alkenyl group, a substituted or unsubstituted C<NUM> to C<NUM> cycloalkyl group, a substituted or unsubstituted C<NUM> to C<NUM> heterocycloalkyl group, a C<NUM> to C<NUM> alkoxy group, a C<NUM> to C<NUM> aryl group or aryloxy group, a C<NUM> to C<NUM> heteroaryl group, a substituted or unsubstituted C<NUM> to C<NUM> alkoxy carbonyl alkyl group, a substituted or unsubstituted C<NUM> to C<NUM> carbonyl alkyl group, an amino group, or a hydroxyl group.

Here, "substituted" means that a hydrogen atom is substituted with a substituent, for example, a C<NUM> to C<NUM> alkyl group, a halogen atom, a nitro group, a cyano group, a hydroxyl group, an amino group, a C<NUM> to C<NUM> aryl group, a C<NUM> to C<NUM> cycloalkyl group, a C<NUM> to C<NUM> heterocycloalkyl group, a C<NUM> to C<NUM> heteroaryl group, and combinations thereof.

In addition, "alkyl", "alkoxy" and other substituents containing an "alkyl" moiety comprise linear or branched structures, and "alkenyl" comprises linear or branched structures having <NUM> to <NUM> carbon atoms and containing at least one double bond. In addition, "cycloalkyl" comprises saturated monocyclic or saturated bicyclic structures having <NUM> to <NUM> carbon atoms. Further, "aryl" is an organic radical derived from an aromatic hydrocarbon through removal of one hydrogen atom therefrom and comprises single or fused ring systems containing suitably <NUM> to <NUM>, preferably <NUM> or <NUM> atoms in each ring. Specifically, "aryl" may comprise phenyl, naphthyl, biphenyl, tolyl,.

Here, "heterocycloalkyl" means a cycloalkyl group containing <NUM> to <NUM> heteroatoms selected from N, O, and S as saturated cyclic hydrocarbon backbone atoms, in which the remaining saturated monocyclic or bicyclic ring backbone atoms are carbon atoms, and may comprise pyrrolidinyl, azetidinyl, pyrazolidinyl, oxazolidinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, thiazolidinyl, hydantoinyl, valerolactamyl, oxylanyl, oxetanyl, dioxolanyl, dioxanyl, oxathiolanyl, oxathianyl, dithianyl, dihydrofuranyl, tetrahydrofuranyl, dihydropyranyl, tetrahydropyranyl, tetrahydropyridinyl, tetrahydropyrimidinyl, tetrahydrothiophenyl, tetrahydrothiopyranyl, diazepanyl, azepanyl.

In addition, "heteroaryl" means an aryl group containing <NUM> to <NUM> heteroatoms selected from N, O, and S as aromatic ring backbone atoms, in which the remaining ring backbone atoms are carbon atoms. The heteroaryl group may comprise a divalent aryl group in which a heteroatom in the ring is oxidized or quaternized to form, for example, an N-oxide or a quaternary salt. Specifically, the heteroaryl group may comprise furyl, thiophenyl, pyrrolyl, pyranyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl.

In some embodiments, the phosphazene flame retardant may be present in an amount of about <NUM> parts by weight to about <NUM> parts by weight, for example, about <NUM> parts by weight to about <NUM> parts by weight, relative to about <NUM> parts by weight of the polycarbonate resin. If the content of the phosphazene flame retardant is less than about <NUM> parts by weight relative to about <NUM> parts by weight of the polycarbonate resin, the thermoplastic resin composition can suffer from deterioration in flame retardancy, fluidity, and if the content of the phosphazene flame retardant exceeds about <NUM> parts by weight, the thermoplastic resin composition can suffer from deterioration in impact resistance, dimensional stability.

In some embodiments, the thermoplastic resin composition may further comprise additives used for typical thermoplastic resin compositions. Examples of the additives may comprise antioxidants, anti-dripping agents, lubricants, release agents, nucleating agents, antistatic agents, stabilizers, pigments, dyes, and mixtures thereof, without being limited thereto. The additives may be present in an amount of about <NUM> parts by weight to about <NUM> parts by weight, for example, about <NUM> parts by weight to about <NUM> parts by weight, relative to about <NUM> parts by weight of the polycarbonate resin.

In some embodiments, the thermoplastic resin composition may be prepared in pellet form by mixing the aforementioned components, followed by melt extrusion at about <NUM> to about <NUM>, for example, at about <NUM> to about <NUM>, using a typical twin-screw extruder.

In some embodiments, the thermoplastic resin composition may have a coefficient of linear expansion of about <NUM>/m·°C to about <NUM>/m·°C, for example, about <NUM>/m·°C to about <NUM>/m·°C, in a resin flow transverse direction, as measured on an injection-molded specimen having a size of <NUM> × <NUM> × <NUM> while heating the specimen from <NUM> to <NUM> at <NUM> /min using a thermo-mechanical analyzer in accordance with ASTM D696.

In some embodiments, the thermoplastic resin composition may have a flame retardancy of V-<NUM>, as measured on a <NUM> thick injection-molded specimen by a UL-<NUM> vertical test method.

In some embodiments, the thermoplastic resin composition may have a notched Izod impact strength of about <NUM> kgf·cm/cm to about <NUM> kgf·cm/cm, for example, about <NUM> kgf·cm/cm to about <NUM> kgf·cm/cm, as measured on a <NUM>/<NUM>" thick specimen in accordance with ASTM D256.

In some embodiments, the thermoplastic resin composition may have a yellowness index (YI) of about <NUM> to about <NUM>, for example, about <NUM> to about <NUM>, as measured in accordance with ASTM D1925.

A molded product according to the present invention is manufactured from the thermoplastic resin composition as set forth above. The thermoplastic resin composition may be prepared in pellet form. The prepared pellets may be produced into various molded products (articles) by various molding methods, such as injection molding, extrusion molding, vacuum molding, and casting. These molding methods are well known to those skilled in the art. The molded product has good properties in terms of dimensional stability, flame retardancy, impact resistance, color, and balance therebetween, and thus can be advantageously used for interior/exterior materials for electrical/electronic articles, thin sheets.

In some embodiments, the molded product may have a coefficient of linear expansion of about <NUM>/m·°C to about <NUM>/m·°C in the resin flow transverse direction, as measured on an injection-molded specimen having a size of <NUM> × <NUM> × <NUM> while heating the specimen from <NUM> to <NUM> at <NUM> /min in accordance with ASTM D696, a flame retardancy of V-<NUM>, as measured on a <NUM> thick injection-molded specimen by a UL-<NUM> vertical test method, a notched Izod impact strength of about <NUM> kgf·cm/cm to about <NUM> kgf·cm/cm, as measured on a <NUM>/<NUM>" thick specimen in accordance with ASTM D256 and a yellowness index (YI) of about <NUM> to about <NUM>, as measured in accordance with ASTM D1925, and may be advantageously used for large extrusion and injection-molded products (interior/exterior materials for electrical/electronic products) having a longitudinal length of about <NUM> to about <NUM>, a transverse length of about <NUM> to about <NUM>, and a thickness of about <NUM> to about <NUM>.

Next, the present invention will be described in more detail with reference to some examples. It should be understood that these examples are provided for illustration only and are not to be construed in any way as limiting the invention.

Details of components used in Examples and Comparative Examples are as follows.

A bisphenol-A polycarbonate resin having a weight average molecular weight (Mw) of <NUM>,<NUM>/mol was used.

Polyethylene terephthalate (PET, Manufacturer: Lotte Chemical Co. , Inherent viscosity: <NUM> dl/g) was used.

(C1) Glass fiber having a rectangular cross-section, a cross-section aspect ratio (long-side length/short-side length in cross-section) of <NUM>, a short-side length of <NUM>, and a pre-processing length of <NUM> (Manufacturer: Nittobo Co. , Product Name: CSG 3PA-<NUM>) were used.

(C2) Glass fiber having a circular cross-section, a cross-section diameter of <NUM>, and a pre-processing length of <NUM> (Manufacturer: KCC, Product Name: CS321-EC10-<NUM>) were used.

(D1) Talc having an average particle diameter (D50) of <NUM> (Manufacturer: KOCH, Product Name: KCP-<NUM>) was used.

(D2) Talc having an average particle diameter (D50) of <NUM> (Manufacturer: KOCH, Product Name: KCM-<NUM>) was used.

(D3) Mica having an average particle diameter (D50) of <NUM> (Manufacturer: IMERYS Co. , Product Name: <NUM>-S) was used.

(E1) A phosphazene compound (Manufacturer: Fushimi Pharmaceutical Co. , Product Name: Rabitle FP-<NUM>) was used.

(E2) Bisphenol-A diphosphate (Manufacturer: Yoke Chemical Co. , Product Name: YOKE BDP) was used.

The above components were mixed in amounts as listed in Tables <NUM> to <NUM> and subjected to extrusion under conditions of <NUM>, thereby preparing a thermoplastic resin composition in pellet form. Extrusion was performed using a twin-screw extruder (L/D=<NUM>, Φ: <NUM>) and the prepared pellets were dried at <NUM> for <NUM> hours or more and injection-molded in a <NUM> oz (* <NUM>). injection molding machine (molding temperature: <NUM>, mold temperature: <NUM>), thereby preparing specimens. The prepared specimens were evaluated as to the following properties by the following method, and results are shown in Tables <NUM> to <NUM>.

From the result, it could be seen that the thermoplastic resin compositions according to the present invention had good properties in terms of dimensional stability, flame retardancy, impact resistance, color.

Claim 1:
A thermoplastic resin composition comprising:
about <NUM> parts by weight of a polycarbonate resin;
about <NUM> part by weight to about <NUM> parts by weight of a polyester resin;
about <NUM> parts by weight to about <NUM> parts by weight of glass fiber having a rectangular cross-section, a cross-section aspect ratio (long-side length/short-side length in cross-section) of about <NUM> to about <NUM>, a short-side length of about <NUM> to about <NUM>, and a pre-processing length of about <NUM> to about <NUM> as measured by the method outlined in the description;
about <NUM> parts by weight to about <NUM> parts by weight of talc having an average particle diameter (D50) of about <NUM> to about <NUM> as measured by the method outlined in the description;
and
about <NUM> parts by weight to about <NUM> parts by weight of a phosphazene flame retardant,
wherein the glass fiber and the talc are present in a weight ratio of about <NUM>:<NUM> to about <NUM>:<NUM>.