WO2009028879A2

WO2009028879A2 - Long fiber reinforced pellet containing inorganic material and resin article manufactured by using the same

Info

Publication number: WO2009028879A2
Application number: PCT/KR2008/005045
Authority: WO
Inventors: Jae Rim Choi; Hyun Ho Cho; Joung Tae Seo; Jong-Min Chae
Original assignee: Gs Caltex Corporation
Priority date: 2007-08-31
Filing date: 2008-08-28
Publication date: 2009-03-05
Also published as: WO2009028879A3; KR20090022835A

Abstract

Disclosed is a long fiber-reinforced pellet containing inorganic materials and a pellet composition for a reinforced resin. The long fiber-reinforced pellet may include a thermoplastic polymer resin, a fiber reinforced material having a length of about 5 to 50 mm; and an inorganic substance having a mean particle size of about 1 to 10 μm. Also, the pellet composition may include an inorganic substance-containing pellet including about 60 to 90 wt. % of a first thermoplastic polymer resin, and about 10 to 40 wt. % of an inorganic substance having a mean particle size of about 1 to 10 μm; and a long fiber-reinforced pellet including about 10 to 90 wt. % of a second thermoplastic polymer resin, and about 10 to 90 wt. % of a fiber reinforced material having a length of about 5 to 50 mm.

Description

LONG FIBER REINFORCED PELLET CONTAINING INORGANIC MATERIALAND RESIN ARTICLE MANUFACTURED BY USING THE SAME

Technical Field The present invention relates to a long fiber-reinforced pellet containing an inorganic substance and an article manufactured using the same, and particularly, to a long fiber-reinforced pellet containing an inorganic substance which may strengthen mechanical characteristics of an article, a pellet composition for a reinforced resin in which an inorganic substance-containing-pellet and a long fiber-reinforced pellet are mixed, and a resin article manufactured using the same.

Background Art

Long fiber-reinforced thermoplastic polymer materials are widely utilized in the entire household electric appliances industry, building material industry, and the like due to their excellent recyclability and moldability, and superior physical properties such as excellent mechanical property and low coefficient of liner expansion as compared with short fiber-reinforced polymer materials. In particular, the use application is expanded in the automotive industry where recycling characteristics and lightening characteristics are required. Meanwhile, thermoplastic polymer compounds reinforcing physical properties by adding inorganic substances such as a talc, a mica, calcium carbonate, and the like in the thermoplastic polymer compound are polymer materials widely used due to their effects for reinforcing high thermal and mechanical properties in comparison with their low prices. When the long fiber-reinforced thermoplastic polymer materials and thermoplastic materials containing inorganic substances are combined, excellent mechanical properties and low price may be simultaneously obtained, and which may be expected to be industrially useful, however, there have not been developed any techniques that specifically realize this. In particular, there is a need for studying a particle size, type, and amount of an inorganic substance, which may optimize mechanical properties of an article in thermoplastic polymer materials simultaneously containing the inorganic substance and a long fiber, and also studying characteristics of the thermoplastic polymer resin, which may exhibit excellent mechanical property when the thermoplastic polymer resin contains the inorganic substance.

Disclosure of Invention Technical Goals

An aspect of the present invention provides a long fiber-reinforced pellet containing an inorganic substance which may exhibit excellent mechanical properties.

An aspect of the present invention provides a long fiber-reinforced pellet containing an inorganic substance which may optimize physical properties, types, and the like of the inorganic substance, thereby preventing deterioration in mechanical property, since a flexural modulus of an article increases along with an increase in an amount of the inorganic substance within the thermoplastic polymer resin, however, deterioration in mechanical properties such as tensile strength, impact strength, and the like may be caused according to the types of the inorganic substance. An aspect of the present invention provides a pellet composition for a reinforced resin which may exhibit the same composition and effects as in the long fiber-reinforced pellet containing the inorganic substance upon manufacturing an article.

An aspect of the present invention provides a resin article containing an inorganic substance which may be manufactured using the long fiber-reinforced pellet containing the inorganic substance, and the pellet composition for the reinforced resin, and exhibit excellent mechanical properties.

Technical solutions

According to an aspect of the present invention, there is provided a long fiber- reinforced pellet containing inorganic materials, including: a thermoplastic polymer resin having a Melt Index (MI) of about 0.1 to 80 g/10min at 230 ^°C and under about 2.16 kg load; a fiber reinforced material having a length of about 5 to 50 mm; and an inorganic substance having a mean particle size of about 1 to 10 μm.

In this instance, the long fiber-reinforced pellet containing the inorganic substance may include: about 20 to 80 wt.% of the thermoplastic polymer resin; about 10 to 40 wt.% of the fiber reinforced material; and about 10 to 40 wt.% of the inorganic substance. Also, the inorganic substance may include a talc, calcium carbonate, and barium sulfate, and a weight ratio of the talc: calcium carbonate: barium sulfate is about 1 :0.5 to 2:0.5 to 2.

Also, the fiber reinforced material may have a mean diameter of about 0.3 to 50 μm, be immersed in the pellet to be parallel to a lengthwise direction of the pellet, and have the same length as that of the pellet.

Also, the fiber reinforced material may be at least one fiber selected from a group consisting of glass fiber, carbon fiber, metal fiber, nylon fiber, polyethylene terephthalate (PET) fiber, poly ether ether ketone (PEEK) fiber, a liquid crystal polymer (LCP) fiber, polyacrylonitrile (PAN) fiber, ultra-high molecular weight polyethylene

(PE) fiber, aramid fiber, and natural fiber.

Also, the inorganic substance may be at least one substance selected from a group consisting of a talc, a mica, a clay, calcium carbonate, barium sulfate, a glass bubble, a glass bead, a ceramic bubble, a whiskers, a chopped glass fiber, a carbon nanotube, and a carbon nanofiber.

Also, the thermoplastic polymer resin may include at least one polymer resin selected from a group consisting of polypropylene, polyamide, polystyrene, styrene acrylonitrile (SAN), acrylonitrile-butadiene-styrene (ABS), polycarbonate (PC), polyurethane (PU), polyoxymethylene (POM), polyethylene terephthalate (PET), polytrimethylene terphthalate (PTT), poly butylene terephthalate (PBT), poly phenylene sulfide (PPS), poly phenylene ether (PPE), poly ether ether kentone (PEEK), a liquid crystal polymer (LCP), polyarylate (PAR), poly methyl pentene (PMP), polysulfone (PSU), poly ether sulfone (PES), and polyimide (PI).

Also, the thermoplastic polymer resin may be polyolefin based-polymer, in which at least one copolymer is mixed, the at least one copolymer being selected from a group consisting of ethylene-α-olefin copolymer with three or more carbon atoms, and styrene-diene copolymer.

Also, the styrene-diene copolymer may include at least one copolymer selected from a group consisting of styrene- butylene-styrene block copolymer, styrene-ethylene- butylene-styrene block copolymer, stylene-isoprene-stylene block copolymer, and stylene-ethylene-propylene-stylene block copolymer.

Also, the polyolefin based-polymer may be modified by unsaturated carboxylic acid and a derivative of unsaturated carboxylic acid.

Also, the polyolefin based-polymer may be grafted in at least one polar group selected from a group consisting of unsaturated carboxylic acid, a derivative of unsaturated carboxylic acid, and an organosilane compound, and a degree of grafting is about 0.3 to 5 wt.%. In this instance, the unsaturated carboxylic acid and the derivative of unsaturated carboxylic acid may be at least one compound selected from a group consisting of maleate, fumaric acid, acrylic acid, itaconic acid, methacrylic acid, maleate anhydride, itaconic anhydride, maleate monoamide, acrylic acid amide, and methacrylic acid natrium. In this instance, the organosilane compound may be at least one compound selected from a group consisting of amino silane, epoxy silane, vinyl silane, and methacryloxy silane.

Also, the long fiber-reinforced pellet may further include: at least one additive selected from a group consisting of an antioxidant, neutralizer, nucleant, anti- electrostatic agent, frame retardant, polish, ultraviolet stabilizer, slip agent, release agent, coloring agent having a surface hardness of about 5 or less, and dispersing agent. In this instance, the additive may be used for stability of polymer, reduction in costs, and the like, and may be used in a range where mechanical property, appearance characteristics, deformable characteristics, and the like may not be rapidly reduced. Also, as the antioxidant, phenol-based antioxidant, phosphate-based antioxidant, thiodipropionate synergist, and the like may be used. Also, as the neutralizer, calcium stearate, zinc oxide, and the like may be used. Also, as the coloring agent, at least one compound selected from a group consisting of ZnS, carbon black, and lithopone may be used. In this instance, the carbon black having a mean particle size of about 30 nm or less and an oil absorption number of about 70 to 150 cc/100 g may be used. According to an aspect of the present invention, there is provided a pellet composition for a reinforced resin, including: an inorganic substance-containing pellet including about 60 to 90 wt.% of a first thermoplastic polymer resin, and about 10 to 40 wt.% of an inorganic substance having a mean particle size of about 1 to 10 μm; and a long fiber-reinforced pellet including about 10 to 90 wt.% of a second thermoplastic polymer resin, and about 10 to 90 wt.% of a fiber reinforced material having a length of about 5 to 50 mm. In this instance, the inorganic substance-containing-pellet and the long fiber-reinforced pellet may be mixed in a weight ratio of about 10:90 to about 50:50. Also, the pellet composition may further include: a resin pellet including a third thermoplastic polymer resin. In this instance, the third thermoplastic polymer resin may be the same type as the first thermoplastic polymer resin or the second thermoplastic polymer resin. Also, the pellet composition may be mixed with the inorganic substance- containing pellet and the long fiber-reinforced pellet, so that the pellet composition may include: about 20 to 80 wt.% of a thermoplastic polymer resin; about 10 to 40 wt.% of a fiber reinforced material having a length of about 5 to 50 mm; and about 10 to 40 wt.% of an inorganic substance having a mean particle size of about 1 to 10 μm. In this instance, the thermoplastic polymer resin may be mixed with first and second thermoplastic polymer resins. In this instance, the first and second thermoplastic polymer resins may be the same type or different types.

Also, the pellet composition may be mixed with the inorganic substance- containing pellet, the long fiber-reinforced pellet, and the resin pellet, so that the pellet composition may include: about 20 to 80 wt.% of a thermoplastic polymer resin; about 10 to 40 wt.% of a fiber reinforced material having a length of about 5 to 50 mm; and about 10 to 40 wt.% of an inorganic substance having a mean particle size of about 1 to 10 μm. In this instance, the thermoplastic polymer resin may be mixed with first, second, and third thermoplastic polymer resins. In this instance, the first, second, and third thermoplastic polymer resins may be the same type or different types. Also, the first, second, and third thermoplastic polymer resins may be the same type as the thermoplastic polymer resin included in the long fiber-reinforced pellet containing the inorganic substance. Specifically, the first, second, and third thermoplastic polymer resins may respectively include at least one polymer resin selected from a group consisting of polypropylene, polyamide, polystyrene, styrene acrylonitrile (SAN), acrylonitrile-butadiene-styrene (ABS), polycarbonate (PC), polyurethane (PU), polyoxymethylene (POM), polyethylene terephthalate (PET), polytrimethylene terphthalate (PTT), poly butylene terephthalate (PBT), poly phenylene sulfide (PPS), poly phenylene ether (PPE), poly ether ether kentone (PEEK), a liquid crystal polymer (LCP), polyarylate (PAR), poly methyl pentene (PMP), polysulfone (PSU), poly ether sulfone (PES), and polyimide (PI).

Also, the first, second, and third thermoplastic polymer resins may respectively be polyolefin based-polymer, in which at least one copolymer is mixed, the at least one copolymer being selected from a group consisting of ethylene-α-olefm copolymer with three or more carbon atoms, and styrene-diene copolymer. In this instance, specific types and characteristics of the ethylene-α-olefin copolymer, the styrene-diene copolymer, and the polyolefin based-polymer may be the same as those in the long fiber-reinforced pellet containing the inorganic substance as described above, and thus detailed descriptions thereof will be omitted.

Also, at least one thermoplastic polymer resin of the first thermoplastic polymer resin and the second thermoplastic polymer resin may have an MI of about 0.1 to 80 g/10 min at about 230 ^°C and under about 2.16 kg load. Also, the third thermoplastic polymer resin may have an MI of about 0.1 to 80 g/10 min at about 230 ^°C and under about 2.16 kg load.

According to an aspect of the present invention, there is provided a pellet composition for a reinforced resin, including: a) a long fiber-reinforced pellet containing an inorganic substance, the long fiber-reinforced pellet including about 20 to 80 wt.% of a fourth thermoplastic polymer resin, about 10 to 40 wt.% of a fiber reinforced material having a length of about 5 to 50 mm, and about 10 to 40 wt.% of an inorganic substance having a mean particle size of about 1 to 10 μm; b) an inorganic substance-containing pellet, the inorganic substance-containing-pellet including about 60 to 90 wt.% of a fifth thermoplastic polymer resin, and about 10 to 40 wt.% of an inorganic substance having a mean particle size of about 1 to 10 μm; and c) a long fiber-reinforced pellet including about 10 to 90 wt.% of a sixth thermoplastic polymer resin, and about 10 to 90 wt.% of a fiber reinforced material having a length of about 5 to 50 mm. In this instance, the pellet composition for the reinforced resin may include a seventh thermoplastic polymer resin.

Also, the pellet composition may be mixed with the long fiber-reinforced pellet containing the inorganic substance, the inorganic substance-containing pellet, and the long fiber-reinforced pellet, so that the pellet composition include: a) about 10 to 70 wt.% of the long fiber-reinforced pellet containing the inorganic substance; b) about 5 to 80 wt.% of the inorganic substance-containing pellet; and c) about 10 to 90 wt.% of the long fiber-reinforced pellet. In this instance, the thermoplastic polymer resin may be mixed with fourth, fifth, and sixth thermoplastic polymer resins. Also, Also, the pellet composition may be mixed with the long fiber-reinforced pellet containing the inorganic substance, the inorganic substance-containing pellet, the long fiber-reinforced pellet, and the resin pellet, so that the pellet composition include: a) about 10 to 70 wt.% of the long fiber-reinforced pellet containing the inorganic substance; b) about 5 to 80 wt.% of the inorganic substance-containing pellet; and c) about 10 to 90 wt.% of the long fiber-reinforced pellet. In this instance, the thermoplastic polymer resin may be mixed with fourth, fifth, sixth, and seventh thermoplastic polymer resins.

The fourth thermoplastic polymer resin may have an MI of about 0.1 to 80 g/min at 230 ^°C and under about 2.16 kg load.

According to an aspect of the present invention, there is provided a resin article containing an inorganic substance, the resin article including: a fiber reinforced material. In this instance, the fiber reinforced material may have a mean length of about 1 to 5 mm, and the resin article may contain an inorganic substance having a mean particle size of about 1 to 10 μm. In this instance, the fiber reinforced material is contained in about 10 to 40 wt.% based on a total weight of the resin article. Also, the inorganic substance may be contained in about 10 to 40 wt.% based on a total weight of the resin article. Also, the resin article may have a tensile strength of about 730 to 1000 kgf/cm², and an IZOD impact strength of about 9.0 to 15.0 kgf cm/cm. In this instance, the resin article containing the inorganic substance may be formed using the long fiber-reinforced pellet containing the inorganic substance, the pellet composition for the reinforced resin, or any combination thereof.

Also, a mean length of the fiber reinforced material that finally remains within the article manufactured using the long fiber-reinforced pellet or the pellet composition for the reinforced resin may be about 1 mm or more, and preferably about 2 mm or more.

Also, an amount of the fiber reinforced material having a length of about 1 mm or more from among all fiber reinforced materials included in the article may be about 10 to 70 wt.%, and a mean length of the fiber reinforced material may be about 1 to 5 mm.

Also, as methods for molding the article, injection molding, extrusion molding, blow molding, foam molding, gas injection molding, gas injection molding, metal insert injection molding, and the like may be used, however, the present invention is not limited thereto. In particular, the injection molding and the metal insert injection molding methods may be preferably used.

Also, the resin article may include a resin having an MI of about 0.1 to 80 g/10 min at 230 ^°C and under about 2.16 kg load.

Advantageous Effect

When molding using the pellet composition for a reinforced resin in which a long fiber-reinforced pellet containing an inorganic substance or a pellet containing the inorganic substance, a long fiber reinforced pellet, and the like are mixed according to the present invention, excellent tensile strength and impact strength may be achieved. Also, since a high flexural modulus may be achieved without deteriorating the tensile strength and the impact strength of an article, it is possible to optimize mechanical properties. Also, by using the long fiber reinforced pellet containing both the inorganic substance and the long fiber, it is possible to manufacture an article having excellent mechanical properties and reduce manufacturing costs. In particular, when manufacturing the article, the pellet composition for a reinforced resin having the same composition as the long fiber reinforced pellet containing the inorganic substance may also achieve the same effect as the long fiber reinforced pellet containing the inorganic substance.

Best Mode for Carrying Out the Invention

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.

A long fiber-reinforced pellet containing an inorganic substance according to an exemplary embodiment of the invention includes a thermoplastic polymer resin, a fiber reinforced material having a length of about 5 to 50 mm, and an inorganic substance having a mean particle size of about 1 to 10 μm.

In this instance, the long fiber-reinforced pellet may include about 20 to 80 wt. % of the thermoplastic polymer resin, about 10 to 40 wt.% of the fiber reinforced material, and about 10 to 40 wt.% of the inorganic substance.

When an amount of the thermoplastic polymer resin is about 80 wt.% or more based on the long fiber-reinforced pellet, an impact strength and bending characteristics may be deteriorated, and when the amount of the thermoplastic polymer resin is about 20 wt.% or less based on the long fiber-reinforced pellet, moldability may be deteriorated. Accordingly, the thermoplastic polymer resin is preferably contained in about 20 to 80 wt.% based on a total weight of the long fiber-reinforced pellet.

Also, when an Melt Index (MI) of the thermoplastic polymer resin at 230^°C and under about 2.16 kg load is about 0.1 g/10 min or less, the productivity may be reduced, or flow marks may occur on final productions. Also, when an MI of the thermoplastic polymer resin at 230 ^°C and under about 2.16 kg load is about 80 g/10 min, desired mechanical properties may be difficult to obtain regarding impact resistance, tensile strength, impact strength, bending strength, and the like. Accordingly, an MI of the thermoplastic polymer resin at 230 ^°C and under about 2.16 kg load is preferably about 0.1 to 80 g/10 min.

Also, the thermoplastic polymer resin includes at least one polymer resin selected from a group consisting of polypropylene, polyamide, polystyrene, styrene acrylonitrile (SAN), acrylonitrile-butadiene-styrene (ABS), polycarbonate (PC), polyurethane (PU), polyoxymethylene (POM), polyethylene terephthalate (PET), polytrimethylene terphthalate (PTT), poly butylene terephthalate (PBT), poly phenylene sulfide (PPS), poly phenylene ether (PPE), poly ether ether kentone (PEEK), a liquid crystal polymer (LCP), polyarylate (PAR), poly methyl pentene (PMP), polysulfone (PSU), poly ether sulfone (PES), and polyimide (PI). Theses polymer resins may be used alone, or a combination thereof.

Of these thermoplastic polymer resins, the polyolefϊn-based polymer resin may be used alone or mixed with a rubber resin. The rubber resin is mixed with at least one copolymer selected from a group consisting of ethylene-α-olefm copolymer with three or more carbon atoms, and styrene-diene copolymer. The ethylene-α-olefin copolymer may include α-olefin and ethylene with three or more carbon atoms, and the ethylene may be contained in about 10 to 90 wt.% in the ethylene-α-olefin copolymer, and more preferably, about 15 to 85 wt.%. The ethylene-α-olefin copolymer includes at least one copolymer selected from a group consisting of ethylene-propylene copolymer, ethylene-butene-1 copolymer, and ethylene-octene copolymer.

An aromatic vinyl compound may be contained in about 10 to 50 wt.% in the styrene-diene copolymer. When an amount of the aromatic vinyl compound in the styrene-based copolymer rubber is about 10 wt.% or less, moldability may be deteriorated, and when the amount of the aromatic vinyl compound therein is about 50 wt.% or more, impact resistance at low temperature may be reduced. The styrene- diene copolymer rubber is a block copolymer including the aromatic vinyl compound such as styrene, vinyl toluene, methyl styrene, and a diene compound such as butadiene, isoprene, and the like, and a compound obtained by adding hydrogen to the styrene- diene copolymer may be used as the styrene-diene copolymer rubber.

As representative examples of the styrene-diene copolymer rubber, styrene- butylene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, stylene-isoprene-stylene block copolymer, and stylene-ethylene-propylene-stylene block copolymer may be given, and these copolymers may be used alone or in a combination thereof.

Also, the polyolefin-based polymer may be modified by unsaturated carboxylic acid and a derivative of unsaturated carboxylic acid. The polyolefin based-polymer is grafted in at least one polar group selected from a group consisting of unsaturated carboxylic acid, a derivative of unsaturated carboxylic acid, and an organosilane compound, and a degree of grafting is about 0.3 to 5 wt.%.

As the modified polyolefin-based polymer, modified polypropylene may be used. The modified polypropylene may be obtained by grafting, in polypropylene, a polar group such as unsaturated carboxylic acid, a derivative of unsaturated carboxylic acid, an organosilane compound, and the like. In this instance, when the degree of grafting is about 0.3 wt.% or less, bending property, strength, and adhesiveness with urethane foam may be deteriorated, and when the degree of grafting is about 5.0 wt.% or more, impact strength may be reduced. Accordingly, the degree of the grafting is about 0.3 to 5.0 wt.%, and preferably, about 0.5 to 5.0 wt.%.

As examples of the unsaturated carboxylic acid used upon the graft reaction, maleate, fumaric acid, acrylic acid, itaconic acid, and methacrylic acid may be given. Also, as examples of the derivative of unsaturated carboxylic acid used upon the graft reaction, anhydride such as maleate anhydride and itaconic anhydride, and ester such as maleate monoamide, acrylic acid amide, and methacrylic acid natrium, amide, metal salt, and the like may be given. As examples of the organosilane compound, amino silane, epoxy silane, vinyl silane, and methacryloxy silane may be given, and the present invention is not limited thereto. The modified polypropylene may be manufactured by grafting, in a polypropylene resin, any one selected from the above-mentioned polar groups, or any combination thereof.

When an amount of the modified polypropylene is about 1 wt.%, improvement in strength, bending property, and adhesiveness with urethane foam may be difficult to obtain, and when the amount of the modified polypropylene is about 10 wt.% or more, impact strength may be reduced. Accordingly, the modified polypropylene may be preferably contained in about 1 to 10 wt.% with respect to the entire long fiber- reinforced pellet. The long fiber-reinforced pellet may be formed into a cylinder shape, oval shape, a Rugby ball shape, a flat cylinder shape, and the like, and a length of the long fiber-reinforced pellet is about 5 to 50 mm. The fiber reinforced material has a mean diameter of about 0.3 to 50 μm, is immersed in the pellet to be parallel to a lengthwise direction of the pellet, and has the same length as that of the pellet. The length of the fiber reinforced material within the long fiber-reinforced colored pellet is preferably about 5 to 50 mm. When the length of the fiber reinforced material is about 5 mm or less, transformation may be increased, and strength of a weldline part may be reduced, and when the length of the fiber reinforced material is about 50 mm or more, injection from a hopper of a molding apparatus to a cylinder is impossible, thereby reducing moldability.

The fiber reinforced material is at least one fiber selected from a group consisting of glass fiber, carbon fiber, metal fiber, nylon fiber, PET fiber, PEEK fiber, LCP fiber, polyacrylonitrile (PAN) fiber, ultra-high molecular weight polyethylene (PE) fiber, aramid fiber, and natural fiber. Also, in order to increase wettability for a polymer, the fiber reinforced material may use suitable surface treatment agents, for example, coupling agents such as silane, titanate, aluminum, chromium, zirconium, and borane, and may be subjected to an acid treatment. In a case of the glass fiber being mainly used, when γ-aminopropyl trimethoxysilane such as silane based-coupling agents, an epoxy based-coupling agents such as γ-glycidoxypropyltrimethoxysilane, and an vinyl silane-based coupling agents such as vinyl trichlorosilane may be used, the wettability for a polymer may be significantly improved.

When an amount of the fiber reinforced material within the entire long fiber- reinforced pellet is about 10 wt.% or less, the transformation quantity may increase, desired bending property may not be exhibited, and a mechanical property-reinforced effect may be reduced. When the amount of the fiber reinforced material is about 40 wt.% or more, moldability may be deteriorated, and the fiber reinforced material may be cut. Accordingly, the fiber reinforced material may be contained in about 10 to 40 wt.% within the long fiber-reinforced colored pellet.

The inorganic substance of the long fiber-reinforced pellet is at least one substance selected from a group consisting of a talc, a mica, a clay, calcium carbonate, barium sulfate, a glass bubble, a glass bead, a ceramic bubble, a whiskers, a chopped glass fiber, a carbon nanotube, and a carbon nanofiber. In this instance, a mean particle size of the inorganic substance is about 1 to 10 μm.

Also, the inorganic substance includes the talc, calcium carbonate, and barium sulfate, and a weight ratio of the talc: calcium carbonate: barium sulfate is about 1 :0.5 to 2:0.5 to 2, and a total weight of the inorganic substance is about 10 to 40 wt.% based on the pellet.

When the mean particle size of the inorganic substance is about 10 μm or more, a tensile strength and an IZOD impact strength may be deteriorated. Also, when an amount of the inorganic substance is about 10 wt.% or less based on the pellet, a reinforcement effect in a flexural modulus of an article may be deteriorated, and when the amount of the inorganic substance is about 40 wt.% or more, moldability may be deteriorated. When the inorganic substances are the same type, and respective amount of the inorganic substances are the same specific value within a range of about 10 to 40 wt.%, a degree of reinforcement with respect to the flexural modulus of the article is not highly irrelevant to a mean particle size of the inorganic substance. However, when the inorganic substance having a mean particle size of about 10 μm or more is used, the tensile strength and the IZOD impact strength may be significantly deteriorated. In addition, when the inorganic substance having a mean particle size of about 10 μm or less is used, the flexural modulus of the article may be reinforced without a deterioration in the tensile strength and the IZOD impact strength. In this manner, a reinforcement effect with respect to mechanical properties may vary depending on an amount and particle size of the inorganic substance. Thus, according to the present invention, the long fiber-reinforced pellet containing the inorganic substance that may maximize the reinforcement effect of the mechanical properties by means of the inorganic substance is provided.

The long fiber-reinforced pellet containing the inorganic substance may further include at least one additive selected from a group consisting of an antioxidant, a neutralizer, a nucleant, an anti-electrostatic agent, a frame retardant, a polish, an ultraviolet stabilizer, a slip agent, a release agent, a coloring agent, and a dispersing agent. In this instance, the coloring agent has a surface hardness of about 5 or less. Also, as the coloring agent, at least one compound selected from a group consisting of ZnS, carbon black, and lithopone may be used. In this instance, the carbon black having a mean particle size of about 30 nm or less and an oil absorption number of about 70 to 150 cc/100 g may be used.

When the surface hardness of the coloring agent is about 5 or more, a damage of the fiber reinforced material may occur due to collision or friction between the coloring agent and the fiber reinforced material in a process of producing the long fiber- reinforced pellet containing the inorganic substance or in a process of molding a final article using the long fiber-reinforced pellet, thereby deteriorating the mechanical property. Accordingly, according to the present invention, a coloring agent having a surface hardness of about 5 or less may be used. However, in a case of a specific pigment from among pigments having a surface hardness of about 5 or less, a deterioration in the mechanical property may occur due to other characteristics such as a particle size and the like. In particular, in a case of a carbon black, the mechanical property may be deteriorated along with an increase in the particle size and a reduction in the oil absorption number. Specifically, the deterioration in the mechanical property of the article may occur due to characteristics of a specific coloring agent, and according to the present invention, types and characteristics of a pigment used as the coloring agent may be determined in order to minimize the deterioration in the mechanical property.

Also, as the coloring agent, at least one compound selected from a group consisting of ZnS, carbon black, and lithopone may be used. In this instance, all of the compounds may have a surface hardness of about 5 or less. However, in a case of the carbon black, the mean particle size is required to be about 30 run or less and the oil absorption number is required to be about 70 to 150 cc/100 g are required. In this instance, the oil absorption number denotes a criterion showing a capacity for absorbing a liquid by the carbon black. When the oil absorption number of the carbon black is about 70 cc/100g or less, the mechanical property of the article is deteriorated, and when the oil absorption number of the carbon black is about 150 cc/100g or more, the moldability may be deteriorated. Also, when a mean particle size of the carbon black is about 30 nm or more, a coloring capacity and the mechanical property of the article may be deteriorated.

Hereinafter, a pellet composition for a reinforced resin in which an inorganic substance-containing pellet and a long fiber-reinforced pellet are mixed will be described in detail.

The pellet composition may comprise a) an inorganic substance-containing pellet including about 60 to 90 wt.% of a first thermoplastic polymer resin, and about 10 to 40 wt.% of an inorganic substance having a mean particle size of about 1 to 10 μm, and b) a long fiber-reinforced pellet including about 10 to 90 wt.% of a second thermoplastic polymer resin, and about 10 to 90 wt.% of a fiber reinforced material having a length of about 5 to 50 mm. In this instance, the first thermoplastic polymer resin and the second thermoplastic polymer resin may be the same type, or different types. Repeated descriptions about the first and second thermoplastic polymer resin, the inorganic substance, and the fiber reinforced material as in the long fiber-reinforced pellet containing the inorganic substance will be omitted.

The inorganic substance-containing pellet and the long fiber-reinforced pellet are dry mixed in a weight ratio of about 10:90 to about 50:50. A composition ratio of respective elements after mixing may be included in a composition ratio of the long fiber-reinforced pellet containing the inorganic substance. Specifically, an article manufactured by using the pellet composition in which a) inorganic substance- containing pellet and b) long fiber-reinforced pellet are mixed may have the same composition ratio as that in an article manufactured by using the long fiber-reinforced pellet containing the inorganic substance. Also, c) a resin pellet including only a third thermoplastic polymer resin may be further added to the pellet composition for the reinforced resin, and thus controlling an entire composition ratio of the pellet composition for the reinforced resin.

Also, the pellet composition for the reinforced resin may further include a long fiber-reinforced pellet containing an inorganic substance. Specifically, the pellet composition for the reinforced resin may include a) a long fiber-reinforced pellet containing an inorganic substance, the long fiber-reinforced pellet including about 20 to 80 wt.% of a fourth thermoplastic polymer resin, about 10 to 40 wt.% of a fiber reinforced material having a length of about 5 to 50 mm, and about 10 to 40 wt.% of an inorganic substance having a mean particle size of about 1 to 10 μm; b) an inorganic substance-containing-pellet including about 60 to 90 wt.% of a fifth thermoplastic polymer resin, and about 10 to 40 wt.% of an inorganic substance having a mean particle size of about 1 to 10 μm; and c) a long fiber-reinforced pellet including about 10 to 90 wt.% of a sixth thermoplastic polymer resin, and about 10 to 90 wt.% of a fiber reinforced material having a length of about 5 to 50 mm. Similarly, d) a resin pellet including only a seventh thermoplastic polymer resin may be further added to the pellet composition for the reinforced resin. An article manufactured using the pellet composition for the reinforced resin in which a), b) and c) are mixed or using the pellet composition for the reinforced resin in which a), b), c), and d) are mixed may have the same composition ratio as that in an article manufactured using the long fiber-reinforced pellet containing the inorganic substance. Also, the pellet composition for the reinforced resin may include about 10 to 70 wt.% of the long fiber-reinforced pellet containing the inorganic substance; about 5 to 80 wt.% of the inorganic substance-containing pellet; and about 10 to 90 wt.% of the long fiber-reinforced pellet. The pellet composition for the reinforced resin may be mixed with the long fiber-reinforced pellet containing the inorganic substance, the inorganic substance-containing pellet, and the long fiber-reinforced pellet, so that the pellet composition may include about 20 to 80 wt.% of a thermoplastic polymer resin, about 10 to 40 wt.% of a fiber reinforced material having a length of about 5 to 50 mm, and about 10 to 40 wt.% of an inorganic substance having a mean particle size of about 1 to 10 μm. Also, the pellet composition for the reinforced resin may be mixed with the long fiber-reinforced pellet containing the inorganic substance, the inorganic substance-containing pellet, the long fiber-reinforced pellet, and the resin pellet, so that the pellet composition may include about 20 to 80 wt.% of a thermoplastic polymer resin, about 10 to 40 wt.% of a fiber reinforced material having a length of about 5 to 50 mm, and about 10 to 40 wt.% of an inorganic substance having a mean particle size of about 1 to 10 μm.

In this instance, a single type of the inorganic substance may be used or various types of the inorganic substance may be used. Also, a type and amount of the inorganic substance contained in the inorganic substance-containing pellet may be the same as those of the inorganic substance contained in the long fiber-reinforced pellet, however, the present invention is not limited thereto.

In addition, a composition ratio of the manufactured article may have a specific value by a suitable combination of the pellets selected from a group consisting of the long fiber-reinforced pellet containing the inorganic substance, the inorganic substance- containing pellet, the long fiber-reinforced pellet, and the resin pellet.

The article may include the fiber reinforced material, a mean length of the fiber reinforced material is about 1 to 5 nm, and the resin article may include an inorganic substance having a mean particle size of about 1 to 10 μm.

Hereinafter, the present invention will be described in detail by examples. It is to be understood, however, that these examples are for illustrative purpose only, and are not construed to limit the scope of the present invention.

Examples 1 to 4 and Comparative Examples 1 to 3

A long fiber-reinforced pellet containing an inorganic substance was manufactured using a modified polypropylene (mPP), in which a polypropylene resin (PP) having a Melt Index (MI) of about 12 g/10 min at a temperature of about 230^°C and under about 2.16 kg load, and maleic anhydride were grafted in polypropylene by about 1%, also using a glass fiber (LGF) having a diameter of about 17 μm and an inorganic substance. As the inorganic substance, a talc (Tl) having a mean particle size of about 5 μm was used in Examples 1 and 4, calcium carbonate (CC) having a mean particle size of about 2 μm was used in Example 2, barium sulfate (BS) having a mean particle size of about 2 μm was used in Example 3, and a talc (T2) having a mean particle size of about 12 μm was used in Comparative Examples 1 and 2, respectively. In Comparative Example 3, any inorganic substance was not used. Here, elements and a weight ratio between the elements used in Examples 1 to 4, and Comparative Examples 1 to 3 are shown in Table 1 below. [Table 1]

According to the composition in Table 1, a long fiber-reinforced pellet containing an inorganic substance having a length of about 10 mm was manufactured so that a length of the glass fiber is the same as that of the pellet. In order to measure a tensile strength, a flexural modulus, and an IZOD impact strength of the manufactured pellet using an injection machine having a clamping force of about 150 tons in accordance with American Society for Testing and Materials (ASTM) standards, samples were manufactured, and the physical property was measured based on ASTM standards. The tensile strength, the flexural modulus, and the IZOD impact strength were measured at room temperature (about 23 "C) using Notched samples based on ASTM D638, ASTM D790, and ASTM D256, respectively.

Ten samples were estimated to obtain mean values with respect to the respective physical properties, and the results are shown in Table 2 below. [Table 2]

As can be seen in the results, the pellets have similar values in the tensile strength and the IZOD impact strength, but have a great difference in flexural modulus, as compared the mechanical properties of the pellet containing an inorganic substance having a mean particle size of about 10 μm in Examples 1 to 4, and the pellet containing only the fiber reinforced material without the inorganic substance in Comparative Example 3. Specifically, in a case of the pellet containing the inorganic substance having a mean particle size of about 10 μm or less, the flexural modulus may be significantly increased without a deterioration in the tensile strength and the IZOD impact strength. Meanwhile, a great difference in the mechanical properties capable of being implemented depending on the particle size of the inorganic substance was shown even when the fiber reinforced materials and the inorganic substances each having the same amount and elements were used, as compared between Example 1 and Comparative Example 1 and also between Example 4 and Comparative Example 2 each including the inorganic substance having the same amount within the pellet. More specifically, when the type and amount of the inorganic substance was the same regardless of the mean particle size of the inorganic substance, a degree of reinforcement of the flexural modulus was similar. However, when the inorganic substance having a mean particle size of about 10 μm or more was used, a great deterioration in the tensile strength and the IZOD impact strength was shown. Conversely, when the inorganic substance having a mean particle size of about 10 μm or less was used, the flexural modulus was reinforced without the deterioration in the tensile strength and the IZOD impact strength, thereby exhibiting more excellent mechanical property.

Examples 5 to 8 and Comparative Examples 4 to 5

A long fiber-reinforced pellet having a length of about 10 mm was manufactured using a modified polypropylene (mPP), in which a polypropylene resin (PP) having an MI of about 12 g/10 min at a temperature of about 230 ^°C and under about 2.16 kg load, and maleic anhydride were grafted in polypropylene by about 1%, also using a glass fiber (LGF) having a diameter of about 17 μm. In this instance, a length of the LGF immersed in the long fiber-reinforced pellet was the same as that of the pellet.

Also, an inorganic substance-containing pellet obtained by concentrating an inorganic substance in PP having the MI of about 12 g/10 min at about 230 ^°C and under about 2.16 kg load was manufactured. As the inorganic substance, a talc (Tl) having a mean particle size of about 5 μm was used in Examples 5 and 8, calcium carbonate (CC) having a mean particle size of about 2 μm was used in Example 6, barium sulfate (BS) having a mean particle size of about 2 μm was used in Example 7, and a talc (T2) having a mean particle size of about 12 μm was used in Comparative Examples 4 and 5, respectively. Here, the inorganic substance-containing pellet was configured in a composition ratio as shown in Table 3 below, and manufactured using a twin screw extruder. Also, the inorganic substance-containing pellet was dry-mixed with the long fiber-reinforced pellet being separately manufactured in a mixed ratio as shown in Table 3 below. Here, elements used in the long fiber-reinforced pellet and the inorganic substance-containing pellet and a weight ratio between the elements are shown in Table 3 below. In this instance, the dry-mixed ratio is a weight ratio of the long fiber- reinforced pellet : the inorganic substance-containing pellet : polypropylene resin. [Table 3]

In order to measure tensile strength, the flexural modulus, and IZOD impact strength of the manufactured pellet using an injection machine having a clamping force of about 150 tons in accordance with American Society for Testing and Materials (ASTM) standards, samples were manufactured, and the physical property was measured based on ASTM standards. Ten samples were estimated to obtain mean values, and the results are shown in Table 4 below.

[Table 4]

As can be seen in the results, the flexural modulus is reinforced without the deterioration in the tensile strength and the IZOD impact strength when the inorganic substance having a mean particle size of about 10 μm or less was used.

Also, the same or similar reinforcement effects of the mechanical properties are shown when respective composition ratio of the inorganic substance and fiber reinforced material within a final article are the same and the type and mean particle size of the inorganic substance are the same, as compared between Examples 1 to 4 in which the long fiber-reinforced pellet containing the inorganic substance is used alone, and Examples 5 to 8 in which the inorganic substance-containing pellet and the long fiber-reinforced pellet are mixed.

Industrial Applicability

As described above, according to the present invention, the long fiber- reinforced pellet containing the inorganic substance and the pellet composition for the reinforced resin may show excellent flexural modulus without the deterioration in the tensile strength and the IZOD impact strength upon manufacturing an article, thereby optimizing the mechanical property, and reducing the manufacturing costs.

Although a few embodiments of the present invention have been shown and described, the present invention is not limited to the described embodiments. Instead, it would be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A long fiber-reinforced pellet containing inorganic materials, comprising: a thermoplastic polymer resin having a Melt Index (MI) of about 0.1 to 80 g/10 min at 230 ^°C and about 2.16 kg load; a fiber reinforced material having a length of about 5 to 50 mm; and an inorganic substance having a mean particle size of about 1 to 10 μm.

2. The long fiber-reinforced pellet of claim 1, wherein the long fiber-reinforced pellet containing inorganic materials comprises: about 20 to 80 wt.% of the thermoplastic polymer resin; about 10 to 40 wt.% of the fiber reinforced material; and about 10 to 40 wt.% of the inorganic substance.

3. The long fiber-reinforced pellet of claim 1, wherein the inorganic substance includes a talc, calcium carbonate, and barium sulfate, and a weight ratio of the talc: calcium carbonate: barium sulfate is about 1:0.5 to 2:0.5 to 2.

4. The long fiber-reinforced pellet of claim 1, wherein the fiber reinforced material has a mean diameter of about 0.3 to 50 μm, and has the same length as that of the long fiber-reinforced pellet.

5. The long fiber-reinforced pellet of claim 4, wherein the fiber reinforced material is at least one fiber selected from a group consisting of glass fiber, carbon fiber, metal fiber, nylon fiber, polyethylene terephthalate (PET) fiber, poly ether ether ketone (PEEK) fiber, a liquid crystal polymer (LCP) fiber, polyacrylonitrile (PAN) fiber, ultrahigh molecular weight polyethylene (PE) fiber, aramid fiber, and natural fiber.

6. The long fiber-reinforced pellet of claim 1, wherein the inorganic substance is at least one substance selected from a group consisting of a talc, a mica, a clay, calcium carbonate, barium sulfate, a glass bubble, a glass bead, a ceramic bubble, a whiskers, a chopped glass fiber, a carbon nanotube, and a carbon nanofiber.

7. The long fiber-reinforced pellet of claim 1, wherein the thermoplastic polymer resin includes at least one polymer resin selected from a group consisting of polypropylene, polyamide, polystyrene, styrene acrylonitrile (SAN), acrylonitrile- butadiene-styrene (ABS), polycarbonate (PC), polyurethane (PU), polyoxymethylene (POM), polyethylene terephthalate (PET), polytrimethylene terphthalate (PTT), poly butylene terephthalate (PBT), poly phenylene sulfide (PPS), poly phenylene ether (PPE), poly ether ether kentone (PEEK), a liquid crystal polymer (LCP), polyarylate (PAR), poly methyl pentene (PMP), polysulfone (PSU), poly ether sulfone (PES), and polyimide (PI).

8. The long fiber-reinforced pellet of claim 1, wherein the thermoplastic polymer resin is polyolefm based-polymer, in which at least one copolymer is mixed, the at least one copolymer being selected from a group consisting of ethylene-α-olefin copolymer with three or more carbon atoms, and styrene-diene copolymer.

9. The long fiber-reinforced pellet of claim 8, wherein the ethylene-α-olefin copolymer includes at least one copolymer selected from a group consisting of ethylene- propylene copolymer, ethylene-butene-1 copolymer, and ethylene-octene copolymer.

10. The long fiber-reinforced pellet of claim 8, wherein the styrene-diene copolymer includes at least one copolymer selected from a group consisting of styrene- butylene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, stylene-isoprene-stylene block copolymer, styrene-ethylene-propylene block copolymer, and stylene-ethylene-propylene-stylene block copolymer.

11. The long fiber-reinforced pellet of claim 8, wherein the polyolefin based- polymer is grafted in at least one polar group selected from a group consisting of unsaturated carboxylic acid, a derivative of unsaturated carboxylic acid, and an organosilane compound, and a degree of grafting is about 0.3 to 5 wt.%.

12. The long fiber-reinforced pellet of claim 1, further comprising: at least one additive selected from a group consisting of an antioxidant, a neutralizer, a nucleant, an anti-electrostatic agent, a frame retardant, a polish, an ultraviolet stabilizer, a slip a agent, a release agent, a coloring agent having a surface hardness of about 5 or less, and a dispersing agent.

13. The long fiber-reinforced pellet of claim 1, wherein the coloring agent includes a carbon black having a mean particle size of about 30 nm or less, and an oil absorption number of about 70 cc/100 g to 150 cc/100 g.

14. A pellet composition for a reinforced resin, comprising: an inorganic substance-containing pellet including about 60 to 90 wt.% of a first thermoplastic polymer resin, and about 10 to 40 wt.% of an inorganic substance having a mean particle size of about 1 to 10 μm; and a long fiber-reinforced pellet including about 10 to 90 wt.% of a second thermoplastic polymer resin, and about 10 to 90 wt.% of a fiber reinforced material having a length of about 5 to 50 mm.

15. The pellet composition of claim 14, wherein the inorganic substance-containing pellet and the long fiber-reinforced pellet are mixed in a weight ratio of about 10:90 to about 50:50.

16. The pellet composition of claim 14, further comprising: a resin pellet including a third thermoplastic polymer resin which is the same type as the first thermoplastic polymer resin or the second thermoplastic polymer resin.

17. The pellet composition of any one of claims 14 and 16, wherein the pellet composition comprises: about 20 to 80 wt.% of a thermoplastic polymer resin; about 10 to 40 wt.% of a fiber reinforced material having a length of about 5 to 50 mm; and about 10 to 40 wt.% of an inorganic substance having a mean particle size of about 1 to 10 μm.

18. The pellet composition of claim 14, wherein at least one thermoplastic polymer resin of the first thermoplastic polymer resin and the second thermoplastic polymer resin has an MI of about 0.1 to 80 g/10 min at 230 ^°C and about 2.16 kg load.

19. A pellet composition for a reinforced resin, comprising: a long fiber-reinforced pellet containing an inorganic substance, the long fiber- reinforced pellet including about 20 to 80 wt.% of a fourth thermoplastic polymer resin, about 10 to 40 wt.% of a fiber reinforced material having a length of about 5 to 50 mm, and about 10 to 40 wt.% of an inorganic substance having a mean particle size of about 1 to 10 μm; an inorganic substance-containing-pellet including about 60 to 90 wt.% of a fifth thermoplastic polymer resin, and about 10 to 40 wt.% of an inorganic substance having a mean particle size of about 1 to 10 μm; and a long fiber-reinforced pellet including about 10 to 90 wt.% of a sixth thermoplastic polymer resin, and about 10 to 90 wt.% of a fiber reinforced material having a length of about 5 to 50 mm.

20. The pellet composition of claim 19, further comprising: a resin pellet including a seventh thermoplastic polymer resin.

21. The pellet composition of claim 19, wherein the fourth thermoplastic polymer resin has an MI of about 0.1 to 80 g/10 min at 230 ^°C and about 2.16 kg load.

22. The pellet composition of claim 19, wherein the pellet composition comprises: about 10 to 70 wt.% of the long fiber-reinforced pellet containing the inorganic substance; about 5 to 80 wt.% of the inorganic substance-containing pellet; and about 10 to 90 wt.% of the long fiber-reinforced pellet.

23. The pellet composition of any one of claims 19 and 20, wherein the pellet composition comprises: about 20 to 80 wt.% of a thermoplastic polymer resin; about 10 to 40 wt.% of a fiber reinforced material having a length of about 5 to 50 mm; and about 10 to 40 wt.% of an inorganic substance having a mean particle size of about 1 to 10 μm.

24. A resin article containing an inorganic substance, the resin article comprising: a fiber reinforced material, wherein the fiber reinforced material has a mean length of about 1 to 5 mm, and is contained in about 10 to 40 wt.% based on a total weight of the resin article, and the resin article contains about 10 to 40 wt.% of the inorganic substance having a mean particle size of about 1 to 10 μm, based on the total weight of the resin article, and has a tensile strength of about 730 to 1000 kgf/cm² and an impact strength of about 9.0 to 15.0 kgf cm/cm.

25. The resin article of claim 24, wherein the resin article is formed using at least one of the long fiber-reinforced pellet containing the inorganic substance of claim 1, the pellet composition for the reinforced resin of claim 14, and the pellet composition for the reinforced resin of claim 19.

26. The resin article of claim 24, wherein the resin article includes a resin having an MI of about 0.1 to 80 g/10 min at 230 ^°C and about 2.16 kg load.