KR20110027904A - Polyester resin composition - Google Patents

Abstract

PURPOSE: A polyester resin composition is provided to improve heat resistance, surface smoothness and surface glossiness, thereby enabling use for interiors or exteriors of automobiles or electrical and electronic components. CONSTITUTION: A polyester resin composition includes (a) 90~99 weight% of polybutylene terephthalate resin, (b) 0.1~2 weight% of talc, (c) 0.4~3 weight% of reactive surfactant, (d) 0.5~5 weight% of layered silicate. The particle size of talc is 5~40 micron. The reactive surfactant comprises an oligomer having a functional group at a terminal group or side chain, or a polymer-shaped reactive compatibilizer, wherein the functional group is selected from the group consisting of maleic anhydride, oxazoline, glycidylmethacrylate, and epoxy.

Description

Polyester resin composition {POLYESTER RESIN COMPOSITION}

This invention relates to the polyester resin composition excellent in heat resistance, surface smoothness, and surface glossiness.

Polyester has excellent mechanical and electrical properties as well as physical and chemical properties, and is applied to a wide range of fields such as automobiles, electrical and electronic devices, and office equipment.

The polyester resins used for the exterior of automobile and electric and electronic parts include polybutylene terephthalate (PBT) and polyethylene terephthalate (PET). PBT is one of the five general-purpose engineering plastics due to its excellent electrical properties and excellent moldability. Such PBT has excellent surface gloss and has a high crystallization rate, which can reduce cycle time during injection molding, thereby increasing product productivity. However, PBT cannot be used for applications exposed to high temperatures alone due to low heat resistance. In order to make up for the disadvantages of PBT, inorganic materials may be mixed in the PBT, but the surface gloss may be reduced, and thus it may not be used in parts requiring surface gloss. In order to compensate for this disadvantage, alloying with PET can improve the surface gloss partly, but in the case of parts with post-processing such as aluminum deposition, which is considerably lower than the surface gloss before mixing inorganic materials, Base coating process is required.

U.S. Patent No. 5,114,998 introduces a resin composition containing a talc, butadiene impact modifier and a stabilizer to prevent resin degradation in the thermoplastic polyester blend. A resin composition containing a shell polymer was introduced. In addition, U.S. Patent No. 4,460,731 introduces a resin composition that suppresses warpage of molded articles by reinforcing glass fibers in a blend of PBT and PET, and U.S. Patent No. 4,370,438 blends PBT and PET in the composition of No. 4,460,731. The resin composition which suppresses the transesterification reaction which added intensity | strength, hardness, an impact modifier (glass fiber etc.), and a flame retardant (halogen type compound, antimony trioxide etc.) is introduced.

Such prior art cannot satisfy the desired heat resistance and surface gloss at the same time, and in order to obtain excellent surface appearance, a separate post process such as painting or coating must be performed on the molded product surface.

Therefore, there are problems such as excessive cost increase, physical property deterioration, heat resistance deterioration and electrical property deterioration due to the performance of the post process. In particular, in the case of a product containing glass fiber, there is a problem that the appearance gloss is extremely reduced due to the protruding surface of the fibrous filler.

An object of the present invention is to provide a polyester resin composition excellent in heat resistance, surface smoothness and surface glossiness.

In addition, by using a polyester resin composition excellent in heat resistance, surface smoothness and surface glossiness, to provide an electrical component, an electronic component, an automotive component, and an industrial molded article excellent in heat resistance and appearance characteristics.

The present invention, a) 90 to 99% by weight of polybutylene terephthalate (PBT) resin; b) 0.1 to 2 weight percent talc; c) 0.4 to 3% by weight reactive surfactant; And d) provides a polyester resin composition comprising 0.5 to 5% by weight of the layered silicate.

Provided are electrical parts, electronic parts, automobile parts, and industrial molded articles manufactured using the polyester resin composition according to the present invention.

The present invention, a) 90 to 99% by weight of polybutylene terephthalate (PBT) resin; Talc 0.1 to 2% by weight; 0.4-3% by weight reactive surfactant; And 0.5 to 5% by weight of the layered silicate is mixed; b) melting and kneading the mixture to prepare pellets; And c) provides a method for producing a polyester resin composition comprising the step of drying the composition prepared in the pellet form after injection molding.

The polyester resin composition according to the present invention includes a talc for improving heat resistance, a reactive surfactant for suppressing surface protrusion, and a layered silicate for improving surface smoothness and surface glossiness, as well as surface smoothness and surface glossiness. As it improves simultaneously, it can be suitably used for both interior and exterior of automobile and electric and electronic parts.

In addition, the polyester resin composition according to the present invention, when applied to the bezel (BEZEL) of an automobile lamp, such as a head lamp (HEAD LAMP), a pogram (FOG LAMP) and a rear combination lamp can exhibit an excellent effect.

Polyester resin composition according to the present invention, a) polybutylene terephthalate (PBT) resin 90 to 99% by weight; b) 0.1 to 2 weight percent talc; c) 0.4 to 3% by weight reactive surfactant; And d) 0.5-5% by weight of layered silicates.

The polyester resin composition which concerns on this invention uses polybutylene terephthalate (PBT) resin as a base resin.

Here, in order to simultaneously improve heat resistance, surface smoothness and surface glossiness, a) polybutylene terephthalate, b) talc for improving heat resistance, c) facilitating bonding of resin and talc and c) inhibiting surface protrusion. A) a reactive surfactant and d) layered silicate for improving surface smoothness and surface glossiness.

The a) the polybutylene terephthalate resin has the advantage of short cycle time and low price.

Specifically, polybutylene terephthalate (PBT) is more moldable than PET, particularly in cycle time, so that polybutylene terephthalate (PBT) and polyethylene terephthalate (PET) are mixed and used. When polybutylene terephthalate (PBT) is used alone, there is an advantage in product mass production.

The a) the polybutylene terephthalate resin is included in 90 to 99% by weight based on the total polyester resin composition, if less than 90% by weight may be the surface gloss, if the weight exceeds 99% by weight May occur.

The polybutylene terephthalate is preferably a polymer polymerized by esterification of butane-1,4-diol and terephthalic acid or a polymer polymerized by transesterification of butane-1,4-diol and dimethyl terephthalate. Can be.

In addition, a modified polybutylene terephthalate may be used to improve the impact strength, but is not particularly limited as long as it is a resin capable of improving the impact strength, but is modified polybutylene terephthalate using chemical modification and modified poly using physical modification. Butylene terephthalate is preferred.

Modified polybutylene terephthalate using chemical modification is polytetramethylene glycol (PTMG), polypropylene glycol (PPG), polyethylene glycol (PEG), low molecular weight aliphatic polyester, Modified polybutylene terephthalate copolymerized by adding low molecular weight aliphatic polyamide and the like.

The modified polybutylene terephthalate using physical modification is a modified polybutylene terephthalate blended with an impact modifier. The impact modifiers include core-shell methacrylonitrile-butadiene-styrene (MBS) polymers with core rubber and shell plastic, all acrylic rubber, and ethylene-propylene. -Ethylene-propylene-diene copolymer (EPDM), styrene-butadien-styrene (SBS) polymer, styrene-isoprene-styrene SIS polymer, styrene-butadiene (styrene-butadien, SB) polymer, styrene-isoprene rubber, ethylene-vinylacetate (EVA) polymer, ethylene-ethyl acrylate (EEA) polymer, ethylene-vinyl Alcohol (ethylene-vinylalchol (EVOH)) polymer, polybutylene terephtalate (PBT) elastomer, polyethylene terephtalate PET elastomer, nylon (nylon) elastomer, etc. Can be used alone or in combination.

The b) talc (talc, Mg ₃ (OH) ₂ Si ₄ O ₁₀ , also known as talc) is a kind of inorganic filler, and is added to the polyester resin composition according to the present invention to impart heat resistance.

The content of b) talc is included in 0.1 to 2% by weight based on the total polyester resin composition.

B) When the content of talc is less than 0.1% by weight, the effect of improving heat resistance may be insufficient, and when the content of the talc exceeds 2% by weight, the effect of improving heat resistance is sufficient but the appearance of the surface due to excessive inorganic matters. This can be degraded. More preferably, the content of b) talc may be 0.1 to 1% by weight.

The size and component of the b) talc is not particularly limited, but the particle size is preferably 5 ~ 40㎛ for smooth productivity and dispersibility.

When the particle size of b) talc is less than 5 μm, quantitative injection is difficult due to the flotation of talc during production, and b) agglomeration between the particles of talc is severe, so that dispersibility in the resin may be poor.

When the particle size of b) talc is greater than 40 μm, the particle size may increase, thereby decreasing surface smoothness and surface glossiness.

In the polyester resin composition according to the present invention, when the a) polybutylene terephthalate and b) talc is included, it can be used only for interior goods in which appearance characteristics are not particularly required.

Therefore, the present invention includes c) a reactive surfactant and d) a layered silicate in order to extend the application to parts requiring high surface properties as well as heat resistance, that is, to improve appearance characteristics.

The c) reactive surfactant can be added to the polyester resin composition according to the present invention to impart surface properties.

The c) reactive surfactant improves the compatibility between the a) polybutylene terephthalate and b) talc component. In addition, the b) talc and d) the finely dispersible inorganic filler of the layered silicate is uniformly dispersed to serve to suppress the surface projection of the components.

The c) reactive surfactant is included in 0.4 to 3% by weight based on the total polyester resin composition.

When the c) content of the reactive surfactant is less than 0.4% by weight, the dispersing effect may be lowered. When the c) content of the reactive surfactant is more than 3% by weight, physical property improvement may be lowered and workability may be poor. . More preferably, c) the content of the reactive surfactant may be 0.5 to 2% by weight.

C) Reactive surfactants include oligomers having a terminal group or a side chain selected from the group consisting of maleic anhydride, oxazoline, glycidyl methacrylate and epoxy; Or a reactive compatibilizer in polymer form.

The interaction of maleic acid, oxazoline, glycidyl methacrylate, epoxy groups and carboxyl groups present in the polyester structure within the reactive surfactant structure promotes compatibility between the components and the uniformity of the finely dispersible inorganic filler. To facilitate distribution.

D) The layered silicate has a layered structure as a compound commonly referred to as polysilicate, and is a type of finely dispersible inorganic filler in which a fine nano-sized layered layer can be dispersed in a resin.

The said layered silicate is added to the polyester resin composition which concerns on this invention, and provides surface smoothness and surface glossiness. And, it is possible to improve the problem that the glass fiber added to the conventional polyester resin composition greatly reduced the characteristics of the appearance surface due to the surface protruding.

In addition, the d) layered silicate has an surface area of several tens to several hundred times or more than a general inorganic filler including glass fiber, and thus effective crystallization of the crystalline resin even with a small amount of additives shows an effect of maintaining impact strength and improving heat resistance. Do it.

The said d) layered silicate is contained in 0.5 to 5weight% with respect to all the polyester resin compositions. Layered silicates of this amount are suitable for achieving the object of the present invention. Here, when less than 0.5% by weight may be less effective in improving the degree of crystallinity, it may be lowered surface gloss when it exceeds 5% by weight. More preferably, the content of d) the layered silicate may be 1 to 4% by weight.

D) As the layered silicate, Montmorillonite, Nontronite, Betelllite, Bonkonskoite, Hectorite, Saponite, Saponite, Smectite-based materials selected from the group consisting of Sauconite, Mecadite, and Kenyaite; Vermiculite-based materials; Illite-based materials; And derivatives thereof. The above d) layered silicates may be used alone or in combination.

More preferably, montmorillonite, nontronite, baydelite, volconscote, laponite, hectorite, saponite, sconite, megadite and kenite can be used.

The polyester resin composition according to the present invention may be a lubricant, an antioxidant, a heat stabilizer, a light stabilizer, a hydrolysis stabilizer, a release agent, a pigment, an antistatic agent, a conductivity-imparting agent, and electromagnetic interference within a range not deteriorating physical properties. EMI may further comprise at least one additive selected from the group consisting of a shielding agent, a magnetic imparting agent, a crosslinking agent, an antibacterial agent, a processing aid, a metal deactivator, a frictional agent, an antiwear agent and a coupling agent.

The polyester resin composition which concerns on this invention can contain the said additive in 0.1 to 2 weight%.

In the polyester resin composition according to the present invention, in order to optimize heat resistance, surface smoothness and surface glossiness, the a) polybutylene terephthalate (PBT) resin; B) talc; C) a reactive surfactant; And d) adjusting the content and particle size of the layered silicate within the above range.

On the other hand, the present invention provides an electrical component, an electronic component, an automobile component, or an industrial molded article manufactured using the polyester resin composition. In particular, when applied to the bezel (BEEZEL) of the automobile lamp, such as head lamp (FOD LAMP), fog lamp (FOG LAMP) and the rear combination lamp can exhibit an excellent effect.

Here, the polyester resin composition according to the present invention may be prepared in a form suitable for application to electrical parts, electronic parts, automobile parts, industrial molded articles.

Here, various electrical insulators such as connectors, switches, bobbins, etc. may be used as electrical components for which the polyester resin composition according to the present invention is used, and various electronic device housings may be cited as electronic components, and lamps may be used as automobile parts. Examples include bezels, door handles, and garnishes. Industrial moldings include tool housings.

As an example, 90 to 99% by weight polybutylene terephthalate resin, 0.1 to 2% by weight talc, 0.4 to 3% by weight reactive surfactant and 0.5 to 5% by weight layered silicate and other additives are added to the super mixer and mixed. The mixed mixture is melted using compounding equipment such as twin-screw extruder, single-screw extruder, roll-mills, kneader, banbury mixer, etc. After kneading, it is prepared in pellet form with a pelletizer. The composition prepared in pellet form may be sufficiently dried in a dehumidifying dryer or a hot air dryer, followed by injection molding to prepare a final polyester molded product.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited thereto.

Examples 1-3, including reactive surfactants and layered silicates

The components of the composition ratio as shown in Table 1 were added in a super mixer, mixed, and melt kneaded using a twin screw extruder, and the kneaded composition was prepared in pellet form with a pelletizer. Then, the pellet-type composition was sufficiently dried in a hot air dryer, followed by injection molding to prepare a final polyester resin composition.

Comparative Examples 1 to 3 (does not contain reactive surfactants and layered silicates)

A polyester resin composition was prepared in the same manner as in Example 1, except that the reactive surfactant and the layered silicate were not included.

Here, in Comparative Example 1, neither the reactive surfactant nor the layered silicate was added. In Comparative Example 2, only the reactive surfactant was not added. In Comparative Example 3, only the layered silicate was not added.

Test Example: Measurement of Physical Properties of Polyester Composition

Tensile strength, elongation, flexural strength, flexural modulus, impact strength, heat deformation temperature and surface gloss of the injection molded specimens of the polyester resin compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were measured as follows. After the measurement, the results are shown in Table 1 below.

division Examples 1-3 Comparative Examples 1-3 Furtherance PBT 90 90 90 90 90 90 (weight%) Talc One One One One One One GMA oligomer ^* One 2 2 - - One Montmorillonite One One 2 - 2 - Properties Tensile strength (kgf / ㎠) 530 560 550 550 560 530 % Elongation 18 25 31 13 16 18 Flexural Strength (kgf / ㎠) 850 870 870 860 880 840 Flexural modulus (kgf / ㎠) 22,500 23,000 22,800 23,000 23,500 22,400 Impact strength (kgfcm / cm) 3 2.8 2.9 2.7 2.9 2.7 Heat deflection temperature (℃) 175 178 180 155 165 158 Surface glossiness 102 105 110 82 84 90 ^* Glycidyl methacrylate (GMA) oligomer (reactive surfactant)

* Tensile strength and elongation: It was measured according to ASTM D638.

* Flexural Strength and Flexural Modulus: measured according to ASTM D790.

Impact strength: measured according to ASTM D256 (1/4 inch thick, Notched Izod).

* Heat deflection temperature: measured according to ASTM D648.

Surface gloss: gloss was measured by a glossmeter (60 degrees).

Through Table 1, Examples 1 to 3 of the reactive surfactant to improve the surface properties by inhibiting the surface protrusion of the components according to the present invention and the layered silicate to improve the surface smoothness and surface glossiness and also improve the heat resistance The polyester resin composition has heat resistance in comparison with the polyester resin composition of Comparative Example 1 containing no reactive surfactant and layered silicate, Comparative Example 2 not containing only reactive surfactant and Comparative Example 3 containing no layered silicate. It turns out that the surface glossiness which shows the heat distortion temperature shown and surface glossiness is high.

In addition, it can be seen that the polyester resin compositions of Examples 1 to 3 and the polyester resin compositions of Comparative Examples 1 to 3 are similar in the mechanical properties of tensile strength, elongation, flexural strength, flexural modulus, and impact strength.

As described above, according to the present invention, it is possible to provide a polyester resin which can be suitably applied for interior and exterior of automobiles and electric and electronic parts by improving not only heat resistance but also surface smoothness and surface glossiness at the same time.

Claims (13)

a) 90-99% by weight of polybutylene terephthalate (PBT) resin; b) 0.1 to 2 weight percent talc; c) 0.4 to 3% by weight reactive surfactant; And d) Polyester resin composition containing 0.5-5 weight% of layered silicates. The method of claim 1, wherein the a) polybutylene terephthalate resin, a polymer of butane-1,4-diol and terephthalic acid; Polymers of butane-1,4-diol and dimethyl terephthalate; Modified polybutylene terephthalate copolymerized with polytetramethylene glycol (PTMG), polypropylene glycol (PPG), polyethylene glycol (PEG), low molecular weight aliphatic polyester and low molecular weight aliphatic polyamide ; And methacrylonitrile-butadiene-styrene (MBS) polymers, all acrylic rubbers, ethylene-propylene-diene copolymers (EPDM), styrene-butadiene-styrene -styrene, SBS) polymer, styrene-isoprene-styrene (SIS) polymer, styrene-butadien (SB) polymer, styrene-isoprene rubber, ethylene-vinylacetate ( ethylene-vinylacetate (EVA) polymer, ethylene-ethyl acrylate (EEA) polymer, ethylene-vinylalchol (EVOH) polymer, polybutylene terephtalate (PBT) -based elastomer, Modified pole blended with at least one impact modifier selected from the group consisting of polyethylene terephtalate PET-based elastomers and nylon-based elastomers Polyester resin composition comprising at least one selected from the group consisting of ributylene terephthalate. The polyester resin composition of Claim 1 whose particle size of said b) talc is 5-40 micrometers. The method according to claim 1, wherein c) the reactive surfactant is an oligomer having a terminal group or a side chain selected from the group consisting of maleic anhydride, oxazoline, glycidyl methacrylate and epoxy; Or a reactive compatibilizer in a polymer form. The method according to claim 1, wherein d) the layered silicate is montmorillonite (Montmori llonite, Nontronite, Beidellite, Volkonskoite, Hectorite, Saponite, Saconite, Saconite, Mecadiite, and Smectite based materials selected from the group consisting of Kenyaite; Vermiculite-based materials; Illite-based materials; And at least one member selected from the group consisting of derivatives thereof. The lubricant, antioxidant, heat stabilizer, light stabilizer, hydrolysis stabilizer, release agent, pigment, antistatic agent, conductivity imparting agent, electromagnetic interference (EMI) shielding agent, magnetic imparting agent, crosslinking agent, antibacterial agent, processing A polyester resin composition further comprising at least one additive selected from the group consisting of an adjuvant, a metal deactivator, an anti-friction agent, an anti-wear agent and a coupling agent. The polyester resin composition according to claim 6, comprising 0.1 to 2% by weight of the additive. An electrical component manufactured using the polyester resin composition according to any one of claims 1 to 7. The electronic component manufactured using the polyester resin composition of any one of Claims 1-7. An automotive part manufactured using the polyester resin composition according to any one of claims 1 to 7. Industrial molded article manufactured using the polyester resin composition of any one of Claims 1-7. a) 90-99% by weight of polybutylene terephthalate (PBT) resin; Talc 0.1 to 2% by weight; 0.4-3% by weight reactive surfactant; And 0.5 to 5% by weight of the layered silicate is mixed; b) melting and kneading the mixture to prepare pellets; And c) Method of producing a polyester resin composition comprising the step of drying the composition prepared in the form of pellets after injection molding. The method according to claim 12, wherein in the step a), an additive is further added.