KR20120069798A - Polyamide-based resin composition with low thermal expansion coefficient - Google Patents

Abstract

PURPOSE: A polyamide-based resin composition is provided to have constant impact strength and to lower coefficient of thermal expansion. CONSTITUTION: A polyamide-based resin composition comprises polyamide, inorganic filler, polyphenylene sulfide, and nano-filler. The inorganic filler is dispersed in polyamide. The nano-filler is dispersed in polyphenylene sulfide. The polyamide is selected from polycaprolactam, poly(11-aminoundecanoic acid), polylauryl lactam, polyhexamethylene adipamide, polyhexaethylene azelamide, polyhexaethylene sebacamide, polyhexa ethylene dodecandiamide, copolymer and mixture thereof.

Description

Polyamide-based Resin Composition with Low Thermal Expansion Coefficient

The present invention relates to a polyamide-based resin composition having a low coefficient of thermal expansion. More specifically, the present invention relates to a polyamide-based resin composition having a low coefficient of thermal expansion, including polyamide, inorganic filler, polyphenylene sulfide and nanofiller.

In the auto industry over the years, efforts have been made to reduce the weight of automobiles, and one of the current considerations as a solution to the weight reduction is to replace the metal shell with plastic.

In line with this, many European automakers are applying a substantial amount of plastic to their fenders, and several Japanese and North American automakers are also applying plastics to their fenders.

The use of plastic as an automobile shell has many advantages such as low-speed impact strength and pedestrian protection due to high energy absorption, in addition to the weight reduction of the automobile, but there is a disadvantage that the space between the shells needs to be more secured due to the high thermal expansion coefficient of the plastic. Done. Generally, metals have a coefficient of thermal expansion of about 10 to 30 μm / m ° C., while plastics have a coefficient of thermal expansion of 70 μm / m ° C. or higher.

On the other hand, polyamide-based resins having excellent chemical resistance, heat resistance, and the like are also widely used as automotive shell material, but have a high coefficient of thermal expansion of about 85 μm / m ° C.

In addition, the polyamide-based resin is also used in conjunction with a rubber-like impact modifier to achieve the impact strength required as a vehicle shell, in which case the coefficient of thermal expansion of the polyamide-based resin is raised to about 10085 μm / m ℃, The problem is bound to be worse.

In order to solve this problem, although carbon fiber reinforced plastic (CFRP) having a low coefficient of thermal expansion (CFRP) is used, it is not generally used for reasons such as high price, and glass fiber reinforced plastic is also used, but automotive exterior panels are required. The use is refrained because of high appearance characteristics.

In addition, in order to solve the above problems, the inorganic fillers such as talc and mica may be reinforced to the polyamide-based resin, but in this case, a disadvantage in that the impact strength drops sharply occurs.

An object of the present invention is to provide a polyamide-based resin composition having a low coefficient of thermal expansion.

Another object of the present invention is to provide a polyamide-based resin composition having a constant impact strength.

Another object of the present invention is to provide a method for producing a polyamide-based resin composition having a low coefficient of thermal expansion and a constant impact strength.

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

Polyamide-based resin composition according to the present invention is (A) polyamide; (B) inorganic fillers; (C) polyphenylene sulfide; And (D) nanofillers.

In one embodiment of the invention, (B) the inorganic filler is dispersed in (A) the polyamide, (D) the nanofiller is dispersed in (C) the polyphenylene sulfide.

In one embodiment of the present invention, the polyamide-based resin composition comprises 30 to 95 parts by weight of polyamide, 0.1 to 35 parts by weight of inorganic filler, 5 to 70 parts by weight of polyphenylene sulfide and 0.1 to 25 parts by weight of nanofiller. .

In one embodiment of the present invention, the polyamide-based resin composition further comprises 0.1 to 20 parts by weight of the (E) impact modifier.

In one embodiment of the present invention, the polyamide is polycaprolactam, poly (11-aminoundecanoic acid), polylauryllactam, polyhexamethylene adipamide, polyhexaethylene azelamide, polyhexaethylene sebacamide, Polyhexaethylene dodecanodiamide, copolymers thereof, and mixtures thereof.

In one embodiment of the present invention, the polyamide has a melting point of 220 to 300 ° C and a relative viscosity of 2 to 4.

In one embodiment of the present invention, the inorganic filler is selected from the group consisting of talc, mica and wollastonite, the average particle size is 0.1 to 50 ㎛.

In one embodiment of the present invention, the polyphenylene sulfide comprises 70 mol% or more of the repeating unit represented by the following formula (1).

[Formula 1]

In one embodiment of the invention, the polyphenylene sulfide is a linear polyphenylene sulfide that does not have a branched or crosslinked structure.

In one embodiment of the present invention, the polyphenylene sulfide has a melt index value of 10 to 300 g / 10 min measured at a temperature of 316 ℃ and a load of 2.16 kg in accordance with ASTM D1238.

In one embodiment of the present invention, the nanofiller is selected from the group consisting of montmorillonite, hectorite, vermiculite, saponite, bentonite, attapulgite, sepiolite and mixtures thereof.

In one embodiment of the invention, the nanofiller is 1 nm to 2 μm in size.

In one embodiment of the present invention, the nanofiller is surface-treated with an organic modifier containing an organic cation.

In one embodiment of the present invention, the organic modifier is a compound having one onium ion capable of ion exchange reaction with the nanofiller, the other has a vinyl group capable of radical polymerization.

In one embodiment of the present invention, the impact modifier is at least one polymer selected from the group consisting of core-shell copolymers, styrene-based polymers, acrylate-based copolymers, silicone-based copolymers and olefin-based copolymers.

In one embodiment of the present invention, the polyamide-based resin composition is antimicrobial agent, heat stabilizer, antioxidant, mold release agent, light stabilizer, compatibilizer, dye, surfactant, coupling agent, plasticizer, admixture, colorant, stabilizer, lubricant, electrostatic It further comprises an additive selected from the group consisting of inhibitors, pigments, flame retardants, weathering agents, colorants, sunscreen agents, nucleating agents, adhesion aids, pressure-sensitive adhesives and mixtures thereof.

Method for producing a polyamide-based resin composition according to the present invention is to produce a masterbatch by extruding (A) polyamide and (B) inorganic filler; And (C) extruding the mixture consisting of polyphenylene sulfide, (D) nanofiller, and (E) impact modifier as the main supply and feeding the masterbatch to the side.

Hereinafter, the present invention will be described in detail.

The polyamide based resin composition according to the present invention has a low coefficient of thermal expansion and a constant impact strength.

1 is a transmission electron microscope (SEM) photograph of the polyamide-based resin composition according to Example 1. FIG.

The polyamide-based resin composition according to the present invention includes (A) polyamide, (B) inorganic filler, (C) polyphenylene sulfide and (D) nanofiller, and may further include (E) impact modifier. .

(A) polyamide

The polyamide refers to a compound containing amino acids, lactams, diamines, dicarboxylic acids and the like as main constituents.

Representative examples of the main constituents include amino acids such as 6-aminocapronic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and paraaminomethylbenzoic acid; lactams such as ε-caprolactam and ω-laurolactam; Tetramethylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methyl Nonamethylenediamine, metaxylenediamine, paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3 , 5,5-trimethylcyclohexane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (amino Propyl) aliphatic, alicyclic, aromatic diamines such as piperazine and aminoethyl piperazine; Or adipic acid, sericinic acid, azelaic acid, sebacic acid, dodecane diacid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, 2 And aliphatic, cycloaliphatic and aromatic dicarboxylic acids such as, 6-naphthalenedicarboxylic acid, hexahydroterephthalic acid and hexahydroisophthalic acid.

In addition, as the polyamide, nylon homopolymers or copolymers derived from these raw materials can be used alone or in the form of mixtures, respectively.

In one embodiment of the present invention, as the polyamide, polycaprolactam (nylon 6), poly (11-aminoundecanoic acid) (nylon 11), polylauryllactam (nylon 12), polyhexamethylene adipamide (nylon 6,6), polyhexaethylene azelamide (nylon 6,9), polyhexaethylene sebacamide (nylon 6,10), polyhexaethylene dodecanodiamide (nylon 6,12) or a copolymer thereof nylon 6 Nylons such as / 6,10, nylon 6 / 6,6, nylon 6/12, etc. may be used alone, or two or more thereof may be mixed and used in an appropriate ratio.

In one embodiment of the present invention, the polyamide has a melting point of 220 to 300 ℃, preferably 240 to 270 ℃, relative viscosity (measured at 25 ℃ by adding 1 part by weight of polyamide to m-cresol) is 2 or more, Preferably 2 to 4. In this case, the mechanical properties and heat resistance of the polyamide-based resin composition can be excellent.

In one embodiment of the present invention, the polyamide may be included in an amount of 30 to 95 parts by weight, preferably 70 to 90 parts by weight. In the case where the polyamide is included in the above range, compatibility with the polyphenylene sulfide may be excellent.

(B) inorganic filler

Mineral fillers such as talc, mica, wollastonite, etc. may be used as the inorganic filler without limitation, and the inorganic filler may include a small amount of aluminum oxide, calcium oxide, iron oxide, and the like. In the present invention, the inorganic filler serves to lower the coefficient of thermal expansion of the polyamide.

In one embodiment of the present invention, the inorganic filler has an average particle size of 0.1 to 50 ㎛, preferably having a flake type shape. When the average particle size of the inorganic filler exceeds 50 μm, the impact strength may be lowered, and when the average particle size is less than 0.1 μm, the thermal expansion coefficient may not be reduced.

In one embodiment of the invention, the inorganic filler is dispersed on the polyamide. In this case, the coefficient of thermal expansion of the polyamide based resin composition can be more effectively reduced.

In one embodiment of the present invention, the inorganic filler may be included in 0.1 to 35 parts by weight, preferably 10 to 15 parts by weight. When the inorganic filler is included in less than 0.1 part by weight, the effect of reducing the coefficient of thermal expansion may not appear, when included in more than 35 parts by weight, impact strength may be lowered.

(C) polyphenylene sulfide

In the present invention, the polyphenylene sulfide is used to compensate for the hygroscopicity of the polyamide, and has a lower coefficient of thermal expansion than the polyamide, thereby helping to reduce the coefficient of thermal expansion of the polyamide-based resin composition.

In one embodiment of the present invention, as the polyphenylene sulfide, polyphenylene sulfide containing 70 mol% or more of the repeating unit represented by the following Chemical Formula 1 may be used. In this case, crystallinity, heat resistance, chemical resistance and impact strength of the polyamide-based resin composition may be excellent.

[Formula 1]

The structure of the polyphenylene sulfide may be a linear structure having no branched or crosslinked structure or a molecular structure having a branched or crosslinked structure depending on the preparation method thereof, and such a structure is well known to those skilled in the art.

In one embodiment of the invention, it is preferable to use linear polyphenylene sulfide having no branched or crosslinked structure as the polyphenylene sulfide. When crosslinked polyphenylene sulfide is used, not only the natural color of the polyamide-based resin composition becomes brown, but also the impact strength and the extrusion characteristics may be lowered. Representative methods for producing such linear polyphenylene sulfides are disclosed in Japanese Patent Laid-Open No. 52-12240.

In one embodiment of the present invention, the polyphenylene sulfide is less than 50 mol%, preferably the repeating unit represented by the following formula 2a, 2b, 2c, 2d, 2e, 2f, 2g or 2h. May contain less than 30 mol%.

(2a)

[Formula 2b]

[Formula 2c]

(2d)

[Formula 2e]

[Formula 2f]

[Formula 2g]

[Formula 2h]

In one embodiment of the present invention, the polyphenylene sulfide has a melt index (MI) value of 10 to 300 g / 10 min measured at a temperature of 316 ℃ and a load of 2.16 kg according to ASTM D1238. When the melt index exceeds 300 g / 10 min, impact strength may be reduced, and when the melt index is less than 10 g / 10 min, workability in kneading and injection processes may be reduced.

In one embodiment of the present invention, the polyphenylene sulfide may be included in 5 to 70 parts by weight, preferably 10 to 30 parts by weight may be included. When the polyphenylene sulfide is included in excess of 70 parts by weight, impact strength and extrusion properties may be lowered, and when included in less than 5 parts by weight, the hygroscopicity and the coefficient of thermal expansion may be reduced.

(D) Nanofillers

The nanofiller is a plate-like mineral having a length and width of about 500 to 2000 mm 3, and a thickness of 9 to 12 mm 3, and the distance between each layer is about 10 mm and is usually in a stacked state in which such plate layers are stacked. To achieve. The nanofiller in the present invention serves to lower the thermal expansion coefficient of the polyamide-based resin composition, in particular serves to lower the thermal expansion coefficient of the polyphenylene sulfide.

In one embodiment of the invention, the nanofiller is a layered silicate selected from the group consisting of montmorillonite, hectorite, vermiculite, saponite, bentonite, attapulgite, sepiolite, and mixtures thereof, preferably commercial Montmorillonite, hectorite, vermiculite, saponite, and mixtures thereof, useful as layered silicates.

In one embodiment of the present invention, the nanofiller preferably has a nanoparticle size, that is, having an average particle diameter of 1 to 100 nm, but has a size of less than 2 μm smaller than the size of the polyphenylene sulfide domain Even if the thermal expansion coefficient reduction effect of the polyamide-based resin composition can be achieved. When the average particle diameter of the nanofiller is a nano level size, the aggregation phenomenon between the nanofiller particles does not occur, and mechanical properties and the like may be improved.

In one embodiment of the present invention, the nanofiller has a cation substitution capacity of 50 to 200 milliliter equivalents per 100 grams, and onium ions such as ammonium ions, quaternary ammonium ions, phosphonium ions and the like containing azo or peroxide groups It can be easily modified through ion exchange reaction. In other words, the nanofiller may be surface treated with an organic modifier containing an organic cation such as onium ions to facilitate organic material penetration between the nanofiller layers.

As the organic modifier, a compound having an onium ion capable of ion exchange reaction with the nanofiller and a vinyl group capable of radical polymerization on the other side is used. Specific examples thereof include dimethyl dihydrotallow quaternary ammonium and dimethyl di. Hydrotallowalkyl ammonium chloride, dimethyl hydrotallowalkyl benzyl ammonium chloride, dimethyl 2-ethylhexyl hydrotallowalkyl ammonium chloride, dimethyl diethoxymethyl hydrotallow alkyl ammonium chloride, trimethyl hydrotallow alkyl ammonium chloride, methyl tallow Bis-2-hydroxyethyl quaternary ammonium, stearyl bis (2-hydroxyethyl) methyl ammonium chloride, vinylbenzyltrimethyl ammonium chloride, vinylbenzyltrimethyl ammonium bromide, vinylbenzyltrimethyl ammonium iodide, vinylbenzyltriethyl ammonium Monium chloride, vinylbenzyltriethyl ammonium bromide, vinylbenzyltriethyl ammonium iodide, 2-methacryloyloxy ethyl trimethyl ammonium chloride, 2-methacryloyloxy ethyl trimethyl ammonium bromide, 2-methacryloyloxy Ethyl trimethyl ammonium iodide, 2-methacryloyloxy ethyl triethyl ammonium chloride, 2-methacryloyloxy ethyl triethyl ammonium bromide, 2-methacryloyloxy ethyl triethyl ammonium iodide, 2- Acryloyloxy ethyl trimethyl ammonium chloride, 2-acryloyloxy ethyl trimethyl ammonium bromide, 2-acryloyloxy ethyl trimethyl ammonium iodide, 2-acryloyloxy ethyltriethyl ammonium chloride, 2-acryloyl jade Ethyl ethyl triethyl ammonium bromide, 2-acryloyloxy ethyl triethyl ammonium iodide, 3- Tacryloylamino propyl trimethyl ammonium chloride, 3-methacryloylamino propyl trimethyl ammonium bromide, 3-methacryloylamino propyl trimethyl ammonium iodide, 3-acryloylamino propyl trimethyl ammonium chloride, 3-acrylo Monoamino propyl trimethylammonium bromide, 3-acryloylamino propyl trimethylammoniumide, diallyldimethyl ammonium chloride, diallyldimethyl ammonium bromide, diallyldimethyl ammonium iodide, and the like, which may be used alone or in a mixture. have.

In one embodiment of the invention, the nanofiller is dispersed on the polyphenylene sulfide. In this case, the coefficient of thermal expansion of the polyamide based resin composition can be more effectively reduced.

In one embodiment of the present invention, the nanofiller may be included in 0.1 to 25 parts by weight, preferably 2 to 6 parts by weight. When the nanofiller is included in less than 0.1 part by weight, the effect of reducing the coefficient of thermal expansion may not appear, and when included in excess of 25 parts by weight, impact strength may be lowered.

(E) Impact modifier

The polyamide-based resin composition according to the present invention may further include an impact modifier.

In one embodiment of the present invention, at least one polymer selected from the group consisting of a core-shell copolymer, a styrene-based polymer, an acrylate-based copolymer, a silicone-based copolymer and an olefin-based copolymer as the impact modifier Can be used.

The core-shell copolymer is a rubber core obtained by polymerizing a diene rubber, an acrylate rubber, a silicone rubber, or a mixture thereof having 4 to 6 carbon atoms, such as methyl methacrylate, styrene, acrylonitrile, or the like. One or more monomers selected from the same unsaturated compounds are graft polymerized to form a core-shell structure. The core-shell copolymer has a hard shell in which a vinyl monomer is grafted to the core structure of rubber.

In one embodiment of the invention, the core-shell copolymer preferably comprises 20 to 90% by weight of the rubber core and 10 to 80% by weight of the shell.

Examples of the diene-based rubber used as the rubber core of the core-shell copolymer include butadiene rubber, acrylic rubber, ethylene / propylene rubber, styrene / butadiene rubber, acrylonitrile / butadiene rubber, isoprene rubber, and ethylene-propylene-diene. Copolymers (EPDM) and the like.

As the acrylate rubber, acrylate monomers such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, etc. At least one selected from among those used is used, and as the curing agent used, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol di Methacrylate, allyl methacrylate, triallyl cyanurate and the like.

Hexamethyl cyclotrisiloxane, octamethyl cyclotetra siloxane, decamethyl cyclopenta siloxane, dodecamethyl cyclohexasiloxane, trimethyltriphenyl cyclotrisiloxane, tetramethyltetraphenyl cyclotetro siloxane, octaphenyl cyclotetra siloxane as the silicone rubber At least one selected from cyclosiloxane compounds, such as the like, may be used, and the curing agent used may include trimethoxy methylsilane, triethoxy phenylsilane, tetramethoxy silane, tetraethoxy silane, and the like.

The olefin copolymer may be prepared using a Ziegler-Natta catalyst which is a general olefin polymerization catalyst, and may be prepared using a metallocene catalyst to make a more selective structure.

In one embodiment of the present invention, in order to improve the dispersibility with the polyphenylene sulfide, a functional group such as maleic anhydride, epoxy and the like may be graft polymerized in the olefin copolymer.

In one embodiment of the present invention, the impact modifier may be included in 0.1 to 20 parts by weight, preferably 5 to 15 parts by weight. When the impact modifier is included in the above range, the impact reinforcement effect may appear, and mechanical strength such as tensile strength, flexural strength, flexural modulus, and the like may be improved.

(F) additive

The polyamide-based resin composition according to the present invention may further include an additive.

In one embodiment of the present invention, the additive is an antibacterial agent, heat stabilizer, antioxidant, release agent, light stabilizer, compatibilizer, dye, surfactant, coupling agent, plasticizer, admixture, colorant, stabilizer, lubricant, antistatic agent, pigment, It is selected from the group consisting of a flame retardant, a weathering agent, a coloring agent, a sunscreen agent, a nucleating agent, an adhesion aid, an adhesive and a mixture thereof.

Phenol type, phosphide type, thioether type, or amine type antioxidant can be used as said antioxidant.

Fluorine-containing polymers, silicone oils, metal salts of stearyl acid, metal salts of montanic acid, montanic acid ester waxes, or polyethylene waxes can be used as the release agent.

As said weathering agent, a benzophenone type or an amine type weathering agent can be used.

Dyestuffs or pigments may be used as the colorant.

Titanium oxide or carbon black may be used as the sunscreen.

Talc or clay may be used as the nucleating agent.

In one embodiment of the present invention, the additive may be included in 0.1 to 30 parts by weight. In this case, the effect of the additive according to each use can be shown within the range which does not impair the objective of this invention.

The polyamide-based resin composition according to the present invention can be produced by a known method. For example, the polyamide-based resin composition may be prepared in pellet form by mixing the components and other additives at the same time, followed by melt extrusion in an extruder.

In one embodiment of the present invention, the method for producing the polyamide-based resin composition is prepared by extruding (A) polyamide and (B) inorganic filler, and (C) polyphenylene sulfide, (D) And a step of extruding the mixture consisting of the nanofiller and (E) the impact modifier as a main supply and feeding the masterbatch to the side.

By the above production method, the inorganic filler may be more dispersed on the polyamide and the nanofiller on the polyphenylene sulfide. As a result, the coefficient of thermal expansion of the polyamide-based resin composition is lowered. 1, it can be seen that the inorganic filler and the polyphenylene sulfide (including nano filler) are properly dispersed in the polyamide.

The polyamide-based resin composition may be applied to various molded products requiring light advantages, excellent chemical resistance and heat resistance, low price, high appearance characteristics, low thermal expansion coefficient, and constant impact strength, and especially low thermal expansion coefficient such as automobile fender and It can be preferably applied to molded articles in the field where constant impact strength is required at the same time.

The present invention will be further illustrated by the following examples, which are used only for the purpose of illustrating the invention and are not intended to limit the scope of the invention.

Example

In one embodiment of the present invention, each component used in the preparation of the polyamide-based resin composition is as follows.

(A) polyamide

Polyamide 6/6 (trade name: VYDYNE 50BW) from Solutia was used.

(B) inorganic filler

Koch's talc (trade name: KCM6300) was used.

(C-1) polyphenylene sulfide

Polyphenylene sulfide (trade name: PPS-HB) from Deyang Chemical was used.

(C-2) polyphenylene ether

Poly (2,6-dimethyl-phenyl) ether (trade name: HPP-820) from GE Plastics was used.

(D-1) Nano Filler

Nanocor's organic montmorillonite (trade name: I44) was used.

(D-2) glass fiber

Nittobo's chopped strand glass fiber (trade name: ECS03T-187H) was used.

(E) Impact modifier

Dupont's ethylene octene copolymer (trade name: FUSABOND MN493D) was used.

Example  1-5 and Comparative Example  1-4

After mixing the polyamide and talc to the content shown in Table 1, the mixture was extruded with a twin screw extruder to prepare a masterbatch. Then, polyphenylene sulfide, nanofiller and impact modifier were mixed in the amounts shown in Table 1 below, and the mixture was used as the main feed and the masterbatch was fed to the side and extruded by a twin screw extruder. After preparing the extrudate in pellet form, the prepared pellet was dried at 100 ° C. for at least 4 hours, and then injected at a temperature of 80 ° C. to prepare a specimen having a size of 12 mm × 6 mm × 10 mm. The physical properties of the prepared specimens were measured by the following method, and the results are shown in Table 1.

(1) coefficient of thermal expansion

Thermo-mechanical Anylyzer (TMA) of TA Instrument was used to measure the thermal expansion coefficient at a temperature increase rate of 5 ° C./min in the range of −40 to 50 ° C.

(2) impact strength

Notched Izod impact strength was measured for 1/8 "specimens in accordance with ASTM D256.

Comparative Example  5

Except for using polyphenylene ether instead of polyphenylene sulfide, and glass fiber instead of nanofiller, the same procedure as in Example 1-5 and Comparative Example 1-4 proceeded, The physical properties of the specimens were measured in the same manner as described above, and the results are shown in Table 1.

Example Comparative Example One 2 3 4 5 One 2 3 4 5 (A) polyamide 90 80 70 75 70 100 100 100 100 50 (B) metal talc 10 10 10 15 15 - 25 - - 24 (C-1) polyphenylene sulfide 10 20 30 10 20 - - - 20 - (C-2) polyphenylene ether - - - - - - - - - 22 (D-1) nano filler 3 3 3 3 3 - - 10 - - (D-2) glass fiber - - - - - - - - - 2 (E) Impact modifier 10 10 10 18 18 10 10 10 10 2 Coefficient of Thermal Expansion (μm / m? ^O C) 63 62 60 66 67 92 60 77 81 57 Impact Strength (kgf? Cm / cm) 13 11 10 14 14 19 4 7 16 6

1 is a transmission electron microscope (SEM) photograph of the polyamide-based resin composition according to Example 1. FIG. 1, it can be seen that inorganic filler and polyphenylene sulfide (including nano filler) are properly dispersed in polyamide.

Referring to Table 1, Example 1-5 includes a specific content of the component according to the present invention while maintaining a low coefficient of thermal expansion (67 μm / m ~ ℃) while maintaining a constant impact strength (10 kgf ~ cm / cm or more) Have

In Comparative Example 1, only the polyamide and the impact modifier were used to increase the coefficient of thermal expansion to 92 μm / m · ° C. In Comparative Example 2, using only polyamide, talc and impact modifier, the coefficient of thermal expansion was lowered, but the impact strength was drastically lowered.

In Comparative Example 3, only the polyamide, the nanofiller, and the impact modifier were used to increase the coefficient of thermal expansion to 77 μm / m · ° C. and the impact strength to 7 kgf · cm / cm. Comparative Example 4 increased the coefficient of thermal expansion to 81 μm / m ~ ℃ using only polyamide, polyphenylene sulfide and impact modifier.

In Comparative Example 5, polyphenylene ether was used instead of polyphenylene sulfide, and glass fiber was used instead of nanofiller, so that the coefficient of thermal expansion was lowered, but the impact strength was sharply lowered. It is expected that this will be degraded.

Simple modifications and variations of the present invention can be easily made by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (17)

(A) polyamide;
(B) inorganic fillers;
(C) polyphenylene sulfide; And
(D) nanofillers;
Polyamide-based resin composition comprising a.
2. The poly according to claim 1, wherein (B) the inorganic filler is dispersed on (A) the polyamide, and (D) the nanofiller is dispersed on (C) the polyphenylene sulfide. Amide system resin composition.
The polyamide of claim 1, wherein the polyamide comprises 30 to 95 parts by weight, 0.1 to 35 parts by weight of the inorganic filler, 5 to 70 parts by weight of the polyphenylene sulfide, and 0.1 to 25 parts by weight of the nanofiller. Amide system resin composition.
The polyamide-based resin composition according to claim 3, further comprising 0.1 to 20 parts by weight of the impact modifier (E).
The polyamide of claim 1, wherein the polyamide is polycaprolactam, poly (11-aminoundecanoic acid), polylauryllactam, polyhexamethylene adipamide, polyhexaethylene azelamide, polyhexaethylene sebacamide, polyhexa A polyamide-based resin composition selected from the group consisting of ethylene dodecanoodiamide, copolymers thereof and mixtures thereof.
The polyamide-based resin composition according to claim 1, wherein the polyamide has a melting point of 220 to 300 ° C and a relative viscosity of 2 to 4.
The polyamide-based resin composition according to claim 1, wherein the inorganic filler is selected from the group consisting of talc, mica and wollastonite, and the average particle size of the inorganic filler is 0.1 to 50 µm.
The polyamide-based resin composition according to claim 1, wherein the polyphenylene sulfide comprises 70 mol% or more of a repeating unit represented by the following Chemical Formula 1.

[Formula 1]

The polyamide-based resin composition according to claim 1, wherein the polyphenylene sulfide is a linear polyphenylene sulfide having no branched or crosslinked structure.
The polyamide-based resin composition according to claim 1, wherein the polyphenylene sulfide has a melt index value of 10 to 300 g / 10 min measured at a temperature of 316 ° C. and a load of 2.16 kg according to ASTM D1238.
The polyamide-based resin composition according to claim 1, wherein the nanofiller is selected from the group consisting of montmorillonite, hectorite, vermiculite, saponite, bentonite, attapulgite, sepiolite and mixtures thereof.
The polyamide-based resin composition according to claim 1, wherein the nanofiller has a size of 1 nm to 2 m.
The polyamide-based resin composition according to claim 1, wherein the nanofiller is surface treated with an organic modifier containing an organic cation.
The polyamide-based resin composition according to claim 13, wherein the organic modifier is a compound having one onium ion capable of ion exchange reaction with the nanofiller and the other having a vinyl group capable of radical polymerization.
The polyamide according to claim 4, wherein the impact modifier is at least one polymer selected from the group consisting of a core-shell copolymer, a styrene polymer, an acrylate copolymer, a silicone copolymer and an olefin copolymer. System resin composition.
The antimicrobial agent, heat stabilizer, antioxidant, mold release agent, light stabilizer, compatibilizer, dye, surfactant, coupling agent, plasticizer, admixture, colorant, stabilizer, lubricant, antistatic agent, pigment, flame retardant, weather agent, A polyamide-based resin composition, further comprising an additive selected from the group consisting of colorants, sunscreens, nucleating agents, adhesion aids, pressure-sensitive adhesives, and mixtures thereof.
Extruding (A) polyamide and (B) inorganic filler to prepare a masterbatch; And
(C) a mixture of polyphenylene sulfide, (D) nanofiller and (E) impact modifier as the main supply, and the masterbatch is fed to the side to extrude;
Method for producing a polyamide-based resin composition comprising the step.

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