Patent Description:
As engineering plastics, a polyester resin and a blend of a polyester resin and a polycarbonate resin exhibit useful properties and are applied to various fields including interior and exterior materials for electric/electronic products. However, the polyester resin has problems of low crystallization rate, low mechanical strength, and low impact strength.

Thus, various attempts have been made to improve mechanical properties including impact resistance and rigidity of the polyester resin by adding additives such as inorganic fillers to the polyester resin. For example, polybutylene terephthalate (PBT) resins reinforced by inorganic fillers, such as glass fiber and the like, are frequently used as materials for automobile components and the like. However, since such materials have a limitation in improvement in impact resistance, rigidity, and the like, there is a problem of deterioration in glass adhesion, metal bonding, and the like.

Therefore, there is a need for development of a thermoplastic resin composition having good properties in terms of glass adhesion, metal bonding, fluidity, impact resistance, and balance therebetween.

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

It is one aspect of the present invention to provide a thermoplastic resin composition having good properties in terms of glass adhesion, metal bonding, fluidity, impact resistance, and balance therebetween, and an article produced therefrom. The present invention relates to a thermoplastic composition, an article made from the composition and a composite material as disclosed in the appended claims.

A thermoplastic resin composition according to the present invention includes: (A) a polybutylene terephthalate resin; (B) a polycarbonate resin; (C) glass fiber; and (D) talc.

As used herein to represent a specific numerical range, "a to b" means "≥ a and ≤ b".

The polybutylene terephthalate (PBT) resin according to the present invention serves to improve properties of the thermoplastic resin composition in terms of glass adhesion, metal bonding, fluidity, impact resistance, and balance therebetween together with the polycarbonate resin and a specific ratio of glass fiber to talc, and may be a polybutylene terephthalate resin used in typical thermoplastic resin compositions. For example, the polybutylene terephthalate resin may be prepared through polycondensation of a dicarboxylic component, such as terephthalic acid (TPA) and the like, and a diol component, such as <NUM>,<NUM>-butane diol, <NUM>,<NUM>-butane diol, and the like.

In some embodiments, the polybutylene terephthalate resin may have an inherent viscosity [η] of <NUM> dl/g to <NUM> dl/g, for example, <NUM> dl/g to <NUM> dl/g, as measured in accordance with ASTM D2857. In some embodiments, the polybutylene terephthalate resin may have an inherent viscosity [η] of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>. Further, according to some embodiments, the polybutylene terephthalate resin may have an inherent viscosity [η] of from any of the foregoing values to any other of the foregoing values. Within this range, the thermoplastic resin composition can exhibit good properties in terms of mechanical properties, metal bonding, fluidity, and the like.

The polycarbonate resin according to the present invention serves to improve the properties of the thermoplastic resin composition in terms of glass adhesion, metal bonding, fluidity, impact resistance, and balance therebetween together with the polybutylene terephthalate resin and a specific ratio of glass fiber to talc and may be a 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 include, 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, <NUM>,<NUM>-bis-(<NUM>,<NUM>-dichloro-<NUM>-hydroxyphenyl)propane, <NUM>,<NUM>-bis(<NUM>-methyl-<NUM>-hydroxyphenyl)propane, and <NUM>,<NUM>-bis(<NUM>,<NUM>-dimethyl-<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, <NUM>,<NUM>-bis(<NUM>-methyl-<NUM>-hydroxyphenyl)propane, <NUM>,<NUM>-bis(<NUM>,<NUM>-dimethyl-<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 tri- or higher valent phenol group-containing compound, in an amount of <NUM> mol% to <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. The polycarbonate resin may be partly or completely replaced by an aromatic polyester-carbonate resin prepared 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 <NUM>,<NUM>/mol to <NUM>,<NUM>/mol, for example, <NUM>,<NUM>/mol to <NUM>,<NUM>/mol, as measured by gel permeation chromatography (GPC). Within this range, the thermoplastic resin composition can have good impact resistance, fluidity (processability), and the like.

In some embodiments, the polycarbonate resin may be present in an amount of <NUM> parts by weight to <NUM> parts by weight, for example, <NUM> parts by weight to <NUM> parts by weight, relative to <NUM> parts by weight of the polybutylene terephthalate resin. In some embodiments, the thermoplastic resin composition may include the polycarbonate resin in an amount of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> parts by weight, relative to <NUM> parts by weight of the polybutylene terephthalate resin. Further, according to some embodiments, the polycarbonate resin can be present in an amount of from any of the foregoing amounts to any other of the foregoing amounts. If the content of the polycarbonate resin is less than <NUM> parts by weight relative to <NUM> parts by weight of the polybutylene terephthalate resin, the resin composition can suffer from deterioration in glass adhesion, fluidity, and the like, and if the content of the polycarbonate resin exceeds <NUM> parts by weight, the resin composition can suffer from deterioration in metal bonding and the like.

According to the present invention, the glass fiber serves to improve the properties of the thermoplastic resin composition in terms of glass adhesion, metal bonding, fluidity, impact resistance, and balance therebetween together with the polybutylene terephthalate resin, the polycarbonate resin and a specific content of talc, and may be glass fiber used in typical thermoplastic resin compositions.

In some embodiments, the glass fiber may have a fibrous shape and may have various cross-sectional shapes, such as circular, elliptical, and rectangular shapes. For example, fibrous glass fiber having circular and/or rectangular cross-sectional shapes may be preferred in terms of mechanical properties.

In some embodiments, the glass fiber having a circular cross-section may have a cross-sectional diameter of <NUM> to <NUM> and a pre-processing length of <NUM> to <NUM>, as measured using a scanning electron microscope (SEM), and the glass fiber having a rectangular cross-section may have an aspect ratio (a ratio of a long-side length to a short-side length on a cross-section) of <NUM> to <NUM>, a short-side length of <NUM> to <NUM>, and a pre-processing length of <NUM> to <NUM>, as measured using the scanning electron microscope. Within this range, the thermoplastic resin composition can have good rigidity, processability, and the like.

In some embodiments, the glass fiber may be subjected to surface treatment with a typical surface treatment agent. The surface treatment agent may include a silane compound, a urethane compound, and an epoxy compound, without being limited thereto.

In some embodiments, the glass fiber may be present in an amount of <NUM> parts by weight to <NUM> parts by weight, for example, <NUM> parts by weight to <NUM> parts by weight, relative to <NUM> parts by weight of the polybutylene terephthalate resin. In some embodiments, the thermoplastic resin composition may include the glass fiber in an amount of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> parts by weight, relative to <NUM> parts by weight of the polybutylene terephthalate resin. Further, according to some embodiments, the glass fiber can be present in an amount of from any of the foregoing amounts to any other of the foregoing amounts. If the content of the glass fiber is less than <NUM> parts by weight relative to <NUM> parts by weight of the polybutylene terephthalate resin, the thermoplastic resin composition can suffer from deterioration in fluidity and the like, and if the content of the glass fiber exceeds <NUM> parts by weight, the thermoplastic resin composition can suffer from deterioration in metal bonding, impact resistance, and the like.

According to the present invention, the talc serves to improve the properties of the thermoplastic resin composition in terms of glass adhesion, metal bonding, fluidity, impact resistance, and balance therebetween together with the polybutylene terephthalate resin, the polycarbonate resin and a specific content of the glass fiber, and may have an average particle diameter of <NUM> to <NUM>.

In some embodiments, the talc is flake type inorganic fillers and may have an average particle diameter of <NUM> to <NUM>, for example, <NUM> to <NUM>, as measured using a particle analyzer (Malvern Mastersizer <NUM>). If the average particle diameter of the talc is less than <NUM>, the thermoplastic resin composition can suffer from deterioration in metal bonding and the like, and if the average particle diameter of the talc exceeds <NUM>, the thermoplastic resin composition can suffer from deterioration in glass adhesion, fluidity, and the like.

In some embodiments, the talc may be present in an amount of <NUM> parts by weight to <NUM> parts by weight, for example, <NUM> parts by weight to <NUM> parts by weight, relative to <NUM> parts by weight of the polybutylene terephthalate resin. In some embodiments, the thermoplastic resin composition may include the talc in an amount of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> parts by weight, relative to <NUM> parts by weight of the polybutylene terephthalate resin. Further, according to some embodiments, the talc can be present in an amount of from any of the foregoing amounts to any other of the foregoing amounts. If the content of the talc is less than <NUM> parts by weight relative to <NUM> parts by weight of the polybutylene terephthalate resin, the thermoplastic resin composition can suffer from deterioration in fluidity and the like, and if the content of the talc exceeds <NUM> parts by weight, the thermoplastic resin composition can suffer from deterioration in metal bonding, fluidity, tensile strength, and the like.

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

The thermoplastic resin composition according to one embodiment of the present invention may further include additives used in typical thermoplastic resin compositions. Examples of the additives may include impact modifiers, flame retardants, antioxidants, anti-dripping agents, lubricants, release agents, nucleating agents, antistatic agents, stabilizers, pigments, dyes, and mixtures thereof, without being limited thereto. In the thermoplastic resin composition, the additives may be present in an amount of <NUM> to <NUM> parts by weight, for example, <NUM> to <NUM> parts by weight, relative to <NUM> parts by weight of the polybutylene terephthalate resin. In some embodiments, the thermoplastic resin composition may include the additive(s) in an amount of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> parts by weight, relative to <NUM> parts by weight of the polycarbonate resin. Further, according to some embodiments, the additive(s) can be present in an amount of from any of the foregoing amounts to any other of the foregoing amounts.

The thermoplastic resin composition according to one embodiment of the present invention may be prepared in pellet form by mixing the aforementioned components, followed by melt extrusion in a typical twin-screw extruder at <NUM> to <NUM>, for example, <NUM> to <NUM>.

In some embodiments, the thermoplastic resin composition may have an average potential energy of <NUM> mJ to <NUM> mJ, for example, <NUM> mJ to <NUM> mJ, as calculated by averaging potential energy values measured upon detachment of five specimens each having a size of <NUM> × <NUM> × <NUM> from a glass substrate having a size of <NUM> × <NUM> × <NUM> by dropping a dart having a weight of <NUM> to <NUM> onto the specimens from a height of <NUM> to <NUM> according to the DuPont drop test method, in which a urethane-based bonding agent (H. , EH9777BS) is applied to a size of <NUM> × <NUM> × <NUM> on each of the specimens at <NUM> and the glass substrate is bonded to the bonding agent, followed by curing under conditions of <NUM> and <NUM>% relative humidity (RH) for <NUM> hours.

In some embodiments, the thermoplastic resin composition may have a metal bonding strength of <NUM> MPa to <NUM> MPa, for example, <NUM> MPa to <NUM> MPa, as measured on an aluminum-based metal specimen in accordance with ISO <NUM>.

In some embodiments, the thermoplastic resin composition may have a melt-flow Index (MI) of <NUM> to <NUM>/<NUM>, for example, <NUM> to <NUM>/<NUM>, as measured under conditions of <NUM> and <NUM> N (<NUM> kgf) in accordance with ASTM D1238.

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

An article according to the present invention is formed of the thermoplastic resin composition set forth above. The thermoplastic resin composition may be prepared in pellet form. The prepared pellets may be produced into various articles (products) by various molding methods, such as injection molding, extrusion, vacuum molding, casting, and the like. These molding methods are well known to those skilled in the art. The articles have good properties in terms of glass adhesion, metal bonding, fluidity, impact resistance, and balance therebetween, and are useful as interior/exterior materials of electric/electronic products, interior/exterior materials of automobiles, interior/exterior materials of portable electronic communication devices, and the like.

A composite material according to the present invention may include a plastic member as the article; a metal member adjoining the plastic member; and a glass member bonded to the plastic member.

In some embodiments, the plastic member may directly adjoin the metal member without a bonding agent therebetween. For example, the plastic member and the metal member may be integrally formed with each other through insert-injection molding.

In some embodiments, the metal member may include at least one metal selected from among aluminum, titanium, iron, and zinc.

In some embodiments, the plastic member and the glass member may be bonded to each other through a bonding agent. For example, after processing a product (the plastic member and the metal member) manufactured by insert injection molding into a desired shape through a CNC process or the like, a glass member may be bonded thereto.

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

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

A polybutylene terephthalate resin (PBT, Manufacturer: Shinkong Synthetic Fibers, Product Name: Shinite K006, inherent viscosity [η]: about <NUM> dl/g) was used.

A bisphenol-A polycarbonate resin (PC, Manufacturer: Lotte Chemical Co. , Weight average molecular weight: about <NUM>,<NUM>/mol) was used.

Flat type glass fiber (Manufacturer: Nittobo, Product Name: CSG 3PA-<NUM>, short-side length: about <NUM>, Aspect ratio on cross-section: about <NUM>, Pre-processing length: about <NUM>) was used.

The aforementioned components were mixed in amounts as listed in Tables <NUM> to <NUM>, followed by extrusion at <NUM>, thereby preparing a thermoplastic resin composition in pellet form. Here, extrusion was performed using a twin-screw extruder (L/D: <NUM>, Φ: <NUM>). The prepared pellets were dried at <NUM> for <NUM> hours or more and then subjected to injection molding using a <NUM> oz. injection machine (molding temperature: about <NUM>, mold temperature: about <NUM>), thereby preparing specimens. The prepared specimens were evaluated as to the following properties. Results are shown in Tables <NUM>, <NUM>, <NUM> and <NUM>.

From the result, it could be seen that the thermoplastic resin composition according to the present invention exhibited good properties in terms of glass adhesion, metal bonding (metal bonding strength), fluidity (melt-flow index), impact resistance (notched Izod impact strength), and balance therebetween.

Conversely, it could be seen that the thermoplastic resin composition of Comparative Example <NUM> prepared using an insufficient amount of the polycarbonate resin exhibited deterioration in glass adhesion, fluidity, and the like; the thermoplastic resin composition of Comparative Example <NUM> prepared using an excess of the polycarbonate resin exhibited deterioration in metal bonding and the like; the thermoplastic resin composition of Comparative Example <NUM> prepared using an insufficient amount of the glass fiber exhibited deterioration in fluidity and the like; and the thermoplastic resin composition of Comparative Example <NUM> prepared using an excess of the glass fiber exhibited deterioration in metal bonding and the like. It could be seen that the thermoplastic resin composition of Comparative Example <NUM> prepared using an insufficient amount of the talc exhibited deterioration in fluidity and the like; and the thermoplastic resin composition of Comparative Example <NUM> prepared using an excess of the talc exhibited deterioration in metal bonding, fluidity, and the like. It could be seen that the thermoplastic resin composition of Comparative Example <NUM> prepared using talc (D4) instead of the talc according to the present invention exhibited deterioration in metal bonding, and the like; and the thermoplastic resin composition of Comparative Example <NUM> prepared using talc (D5) instead of the talc according to the present invention exhibited deterioration in glass adhesion, fluidity, and the like. Further, it could be seen that the thermoplastic resin composition (Comparative Example <NUM>) including the glass fiber and the talc in a weight ratio (C:D1) (<NUM>:<NUM>) less than <NUM>:<NUM> exhibited deterioration in fluidity, impact resistance and the like, and the thermoplastic resin composition (Comparative Example <NUM>) including the glass fiber and the talc in a weight ratio (<NUM>,<NUM>:<NUM>) exceeding <NUM>,<NUM>:<NUM> exhibited deterioration in metal bonding and the like.

Claim 1:
A thermoplastic resin composition comprising:
<NUM> parts by weight of a polybutylene terephthalate resin;
<NUM> parts by weight to <NUM> parts by weight of a polycarbonate resin;
<NUM> parts by weight to <NUM> parts by weight of glass fiber; and
<NUM> parts by weight to <NUM> parts by weight of talc having an average particle diameter of <NUM> to <NUM>, determined using the method indicated in the description,
wherein the glass fiber and the talc are present in a weight ratio of <NUM>:<NUM> to <NUM>,<NUM>:<NUM>.