JP4379151B2 - Polyester resin composition and use thereof - Google Patents

Description

The present invention relates to a polyester resin composition (masterbatch) containing a filler at a high concentration and having high conductivity, rigidity, and thin-wall moldability, and use thereof.

As a filler, composite materials reinforced with thermoplastic resin with inorganic fillers such as talc, mica and carbon black and fibers such as carbon fiber, glass fiber and organic fiber are excellent in impact resistance, chemical resistance and moldability. It is widely used in various industrial fields such as electric / electronic parts, space / aviation field, automobile industry field, energy field, sporting goods field and leisure goods field. However, since various properties cannot be obtained unless the inorganic filler has a high filling amount, and it is difficult to maintain a balance with mechanical properties, in order to maintain a balance between various properties and mechanical properties, Mainly fibers are used. In particular, since organic fibers are a combination (thermoplastic resin and organic fibers) that are materials closer to general plastics, they can be molded easily and can be recycled. It is coming.

On the other hand, conductive fibers such as carbon fiber, metal fiber or metal coated fiber are widely used in IC trays, personal computers, liquid crystal panels, etc. that require electromagnetic shielding and antistatic properties because the substrate is conductive. Moreover, due to concerns about the influence of electromagnetic waves and magnetic fields on the human body due to the recent health orientation, further increase in demand is expected.

As a method for producing a thermoplastic resin composition containing such a filler, for example, a method for producing compound pellets obtained by extruding short carbon fibers and PBT resin with a single screw extruder and then cutting them into a fixed length (Patent Document) 1: Japanese Patent Publication No. 5-83044), similarly, a compound of carbon fiber and polycarbonate (Patent Document 2: Japanese Patent Laid-Open No. 61-241356, Patent Document 3: Japanese Patent Laid-Open No. 04-198224, Patent Document 4: No. 2000-007906), a compound of carbon fiber and polyester (Patent Document 5: Japanese Patent Laid-Open No. 48-663), a compound of glass fiber and polyester (Patent Document 6: published in Japanese Patent No. 2651057), conductive fiber And polyolefin compound (Patent Document 7: JP-A-59-196334, Patent Document 8: Patent 27) 2986 issue of publication), etc. have been disclosed. However, such compound pellets have a problem that various fibers such as carbon fibers are cut short in the extrusion process, and further fibers are cut in the injection molding process, so that the fiber length becomes short. There was a limit to how to improve the mechanical properties.

In addition, thermoplastic resins such as polyolefins and polyesters used for compounds are not very compatible with resins used for engineering plastics such as polycarbonate and polyphenylene ether. There was a problem of causing a decline in sex.

On the other hand, Patent Document 9 (Japanese Patent Publication No. 63-37694) discloses a fiber reinforced structure in which aligned reinforcing filaments are impregnated with a thermoplastic resin. Patent Document 10 (Japanese Patent No. 2626012) discloses a pellet containing 30% by weight or more of fibers arranged in parallel and having a length in the fiber array direction of 3 to 60 mm. Further, Patent Document 11 (Japanese Patent Laid-Open No. 57-181852) and Patent Document 12 (Japanese Patent Laid-Open No. 2003-192911) disclose that the pellet length of the resin-coated fiber pellet is equal to the fiber length. Yes. When resin-coated fiber pellets in which these fibers are coated with resin are injection-molded, the length of the fibers contained in the molded product after molding becomes much longer than that of compound pellets, and the impact resistance and bending elasticity of the molded product are increased. It is described that the rate is improved.

Thus, it has become possible to substantially solve the problem by using a fiber-coated resin composition in which fibers are coated with a resin in advance. However, as in this method, the fiber bundle simply coated with resin has an air layer between the fibers, so that the resin impregnation property is not sufficient. Problems such as poor dispersion of fibers, white turbidity due to diffused reflection of the air layer, rough appearance due to air bubbles coming out immediately after molding, and failure to obtain good mechanical properties due to fiber crushing was there.

In addition, such resin-coated fiber pellets have recently been used for applications that require electromagnetic shielding properties using conductive fibers (for example, PC housings, liquid crystals, etc.). For the same reason, there is a problem that good electromagnetic wave shielding characteristics cannot be obtained because the fibers are difficult to uniformly disperse in the molded product.

From these points, in order to obtain a more practical new fiber-containing resin molded product, the remaining length of the fiber in the molded product is kept as long as possible and the dispersibility of the fiber is increased, thereby maintaining a good surface condition. However, rapid development of a fiber-containing resin composition that can further improve mechanical properties and electrical conductivity has been desired.
Japanese Patent Publication No. 5-83044 JP 61-241356 A Japanese Patent Laid-Open No. 04-198224 JP 2000-007906 A JP-A-48-663 Japanese Patent No. 2651057 JP 59-196334 A Japanese Patent No. 2732986 Japanese Patent Publication No.63-37694 Patent No. 2626012 publication Japanese Patent Laid-Open No. 57-181852 JP 2003-192911 A

In view of the problems of the prior art, the present invention is able to obtain a molded product that maintains high mechanical properties and secures high conductivity, and generates free fibers, poor kneading with resin, An object of the present invention is to provide a polyester-based resin composition in which a filler is impregnated with a copolyester having good resin impregnation property and excellent dispersibility, which suppresses resin reinforcement ability and electrical conductivity decrease due to breakage and the like. To do.

The present invention has an ethylene oxide adduct content of 4,4′-dihydroxydiphenyl-2,2-propane of 10 to 40 mol%,
Copolymerized polyester (A) having a weight average molecular weight of 10,000 to 30,000 is impregnated into a long fiber having a fiber diameter of 4 to 20 μm as a filler by a melt drawing method, and the long fiber is 10 to 10% of the total composition. A polyester resin composition comprising 90% by weight , comprising:
The long fiber is stainless fiber, carbon fiber, Ni-coated carbon fiber, Ag-coated polyester fiber, Cu-coated aramid fiber, polypropylene fiber, acrylic fiber, polyester fiber, aramid fiber, nylon fiber, polybenzoxazoline fiber, cotton fiber hemp fiber And a polyester resin composition characterized by being one or more organic fibers or conductive fibers selected from kenaf fibers .

Furthermore, the present invention is the polyester resin composition according to the first invention, wherein the dicarboxylic acid component of the copolyester (A) is terephthalic acid and isophthalic acid.

The present invention relates to a polyester resin composition of the invention the melt viscosity is less than 10000dPa · s at 200 ° C., as measured in accordance with JIS K7199 of copolyester (A).

Furthermore, the present invention relates to the polyester-based resin composition according to the invention, wherein the long fiber includes a twist of 35 pitches or more and 45 pitches or less per 1 m of length .

Furthermore, the present invention provides a molding comprising the polyester resin composition of the above invention and a thermoplastic resin (B) selected from the group consisting of polyethylene terephthalate, polycarbonate, polyphenylene ether, polyphenylene sulfide, and acrylic, butadiene, and styrene. on goods.

Since the copolymerized polyester (A) used in the present invention is easily impregnated in the filler and has good pellet processing, (1) the bulky filler is compactly combined to increase the specific gravity and the unit volume. Increase the filler content, (2) cover the filler with the copolymer polyester (A) to protect the filler until the production of the molded product, (3) good quantitative supply For this reason, the inclusion of the filler makes it possible to provide a molded product having good mechanical properties and electrical conductivity.

Hereinafter, the present invention will be described in detail.
The copolymer polyester (A) of the present invention preferably has a weight average molecular weight (hereinafter referred to as Mw) of 10,000 to 30,000. When Mw exceeds 30000, impregnation is difficult, and when it is less than 10000, pellet molding becomes difficult, which is not preferable.

The melt viscosity of the copolyester (A) is preferably 10000 dPa · s or less. When the melt viscosity exceeds 10,000 dPa · s, impregnation becomes difficult and a problem occurs in quality. The melt viscosity in the present invention is measured at a test temperature of 200 ° C. according to JIS K7199, and the molecular weight is a weight average molecular weight measured by high temperature GPC.

The copolymer polyester of the present invention is a polyester obtained by mixing and polycondensing a diol component and an aromatic dicarboxylic acid component so that all OH groups are substantially equivalent to all carboxyl groups.

As specific examples of the copolyester (A), any copolyester can be applied as long as the Mw is 10,000 to 30,000 and the melt viscosity is 10000 dPa · s or less. Particularly preferred is a diol component. As a copolymerized polyester resin containing an ethylene oxide adduct of 4,4′-dihydroxydiphenyl-2,2-propane.

(In the formula, m and n are numbers from 0 to 3.)

The content of the ethylene oxide adduct of 4,4′-dihydroxydiphenyl-2,2-propane, which is a diol component constituting the copolymer polyester (A), is preferably 10 to 40 mol%. If it is less than 10 mol%, the compatibility with engineering plastics such as polycarbonate and polyphenylene ether is lowered, and the mechanical properties and electrical conductivity of engineering plastics as molding resins are lowered. Moreover, when it exceeds 40 mol%, copolymerization becomes difficult and the flexibility of the resin becomes insufficient, which is not preferable.

As the diol component constituting the copolymerized polyester in the present invention, any diols generally used other than the ethylene oxide adduct of 4,4′-dihydroxydiphenyl-2,2-propane can be used as the copolymer component. There is no particular limitation. For example, aliphatic glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, trimethylene glycol, propylene glycol, butanediol, pentanediol, neopentyl glycol, hexamethylene glycol, dodecamethylene glycol, cyclohexanedimethanol, etc. Aromatic groups such as 1,3-bis (2-hydroxyethoxy) benzene, 1,2-bis (2-hydroxyethoxy) benzene, 1,4-bis (2-hydroxyethoxy) benzene And aromatic diols such as hydroquinone and 2,2-bis (4-β-hydroxyethoxyphenyl) propane.

These diols may be ester derivatives thereof. These diols may be a combination of two or more.

Examples of the aromatic dicarboxylic acid component constituting the copolyester in the present invention include terephthalic acid, phthalic acid (orthophthalic acid), isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,5- Aromatic dicarboxylic acids such as naphthalenedicarboxylic acid, diphenyldicarboxylic acid, and diphenoxyethanedicarboxylic acid. Among them, aromatic groups having 6 or 10 carbon atoms, that is, dicarboxylic acids having a benzene skeleton or a naphthalene skeleton are preferable, and terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, and the like can be given, among which terephthalic acid and isophthalic acid are preferable. Here, it is possible to use terephthalic acid and isophthalic acid alone as the dicarboxylic acid, but considering compatibility with engineering plastics such as polycarbonate and polyphenylene ether, two types of terephthalic acid and isophthalic acid are essential components. It is preferable to use it.

Moreover, as long as the effect of this invention is not impaired, other polyester components can also be copolymerized. For example, 4 in the copolyester (A) is prepared by previously mixing a copolyester resin containing a high concentration of 4,4′-dihydroxydiphenyl-2,2-propane ethylene oxide adduct and a general polyester resin. If the content of the ethylene oxide adduct of 4,4′-dihydroxydiphenyl-2,2-propane is in the range of 10 to 40 mol%, it can be used as a blended polyester and is not particularly limited.

The melting point of the copolymerized polyester of the present invention as measured by a differential scanning calorimeter (DSC, heating rate 10 ° C./min) is usually 100 to 250 ° C., preferably 120 ° C. to 200 ° C.

The method for producing a copolyester according to the present invention can be produced according to a conventionally known polyester production method. For example, when terephthalic acid and isophthalic acid are directly esterified with 4,4'-dihydroxydiphenyl-2,2-propane ethylene oxide adduct or ethylene glycol, or when dialkyl ester is used as the dicarboxylic acid component Copolymerization by transesterification with ethylene oxide adduct of 4,4'-dihydroxydiphenyl-2,2-propane or ethylene glycol, followed by melt polycondensation reaction to remove excess diol component by heating under reduced pressure Polyester can be produced.

As the catalyst, known ones can be used. Specific examples of the transesterification reaction catalyst include compounds such as magnesium, manganese, titanium, zinc, calcium, cobalt, and the polycondensation catalyst includes antimony, germanium. A compound such as titanium can be used. The addition amount of the transesterification reaction catalyst and the polycondensation catalyst may be arbitrary as long as the reactivity and heat resistance of the polyester are not impaired.

Further, a stabilizer such as a phosphorus compound may be added to the polycondensation step. Specific examples of phosphorus compounds include phosphate esters such as trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, trioctyl phosphate, triphenyl phosphate, triphenyl phosphite, trisdodecyl phosphite, List phosphorous esters such as trisnonylphenyl phosphite, phosphoric acid esters such as methyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, dibutyl phosphate, monobutyl phosphate, dioctyl phosphate, and phosphorous compounds such as phosphoric acid and polyphosphoric acid Can do.

In the polycondensation reaction, the polycondensation catalyst is present in an amount of 0.0005 to 0.2 mol%, preferably 0.001 to 0.1 mol%, in terms of metal atoms in the polycondensation catalyst, with respect to the dicarboxylic acid. It is desirable to do. The polyester obtained in this polycondensation step is usually melt extruded and formed into pellets.

In the present invention, the polyester obtained in this polycondensation step may be further subjected to solid phase polycondensation. For example, the pelletized polyester obtained above is heated at a temperature of 160 ° C. to less than the melting point, preferably 170 to 220 ° C. for 8 to 40 hours, more preferably 15 to 30 hours, and the pressure is usually 1 kg / cm 2 G˜ The solid-phase polycondensation reaction is carried out under an inert gas atmosphere such as nitrogen gas, argon gas, carbon dioxide gas under the conditions of 10 Torr, preferably normal pressure to 100 Torr. Of these inert gases, nitrogen gas is preferred.

The production process of the polyester including the esterification step and the polycondensation step as described above can be performed either batchwise or semi-continuously.

Examples of the filler used in the present invention include calcium carbonate, talc, silica, clay, diatomaceous earth, mica, smectite, calcium carbonate, calcium sulfate, barium sulfate, titanium oxide, zinc oxide, satin white, aluminum silicate, Examples include inorganic fillers such as litbon, alumina, zeolite, carbon black, graphite, metal powder, metal flakes and metal oxides, organic fibers, conductive fibers, etc., but organic fibers and / or conductive fibers. Particularly preferred in terms of various characteristics.

Examples of organic fibers include polyester fiber, nylon fiber, acrylic fiber, aramid fiber, polyamide fiber, polyimide fiber, polylactic acid fiber, silk fiber, wool fiber, rayon fiber, regenerated cellulose fiber, cotton fiber, hemp fiber , Kenaf fibers and the like, and one or more selected from these are used.

For example, as the conductive fiber, one or more kinds selected from metal fibers, metal-coated fibers, and carbon fibers are used.

For example, examples of the metal fiber include stainless steel fiber, copper fiber, nickel fiber, iron fiber, aluminum fiber, silver fiber, zinc fiber, boron fiber, and the like, and one or more selected from these are used.

For example, examples of the metal-coated fiber include carbon fiber or a fiber obtained by coating the surface of the organic fiber with a metal such as copper, silver, nickel, zinc, iron, aluminum, and the like. Used above.

For example, as the carbon fiber, acrylic fiber, pitch, rayon, etc. can be used as raw materials, but carbon fiber produced from acrylic fiber mainly composed of acrylonitrile is excellent in industrial productivity, and It is also preferable because of its excellent mechanical properties. The acrylic fiber is not particularly limited as long as it contains a monomer component that accelerates the flameproofing reaction. Itaconic acid, acrylic acid, methacrylic acid and their methyl ester, ethyl ester, propyl ester, alkali metal salt , Ammonium salts, or allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, and alkali metal salts thereof can be raised, but not limited thereto. The spinning method is preferably a wet spinning method or a dry and wet spinning method, but is not particularly limited.

Acrylic carbon fibers consist of a flameproofing process in which acrylic fibers obtained by polymerizing acrylonitrile as a main component are heated in an air atmosphere at 200 to 400 ° C. to convert them into oxidized fibers, and nitrogen, helium, argon, etc. It is obtained by passing through a carbonization step of carbonizing by heating at a higher temperature in an active atmosphere. The carbon fiber used in the present invention preferably adopts a temperature of 1200 to 2200 ° C. as a temperature for making the acrylic fiber flame resistant and then carbonizing. Preferably it is 1500-2100 degreeC.

Moreover, the volume specific resistance value of the conductive fiber is desirably 10 ⁻³ Ωcm or less, and the volume specific resistance value of the polyester resin composition using these is desirably 10 ⁰ Ωcm or less. This is because the electron wave shielding effect can hardly be expected when it is formed to be 10 ⁰ Ωcm or more.

The fiber diameter of the organic fiber and / or conductive fiber is preferably 4 to 20 μm. If it is less than 4 μm, it becomes bulky and the shearing force in the molten resin becomes weak. If it exceeds 20 μm, the surface of the molded product is not smooth, which is not preferable.

The organic fiber and / or conductive fiber is impregnated with the copolyester (A) with a bundle of 3,000 to 100,000, preferably 5,000 to 25,000 as one unit, and then pelletized to form a polyester resin composition. . Since the bundle of organic fibers and / or conductive fibers affects the thickness of the polyester resin composition, the polyester resin composition is too thin or too thick to be used outside the above range.

As a method for impregnating the filler of the copolymerized polyester (A), for example, in the case of organic fibers and / or conductive fibers, the thermoplastic resin (A) heated to a low viscosity is converted into organic fibers and / or conductive properties. Examples include a known method for impregnating fibers. By this impregnation step, the spaces between the fibers constituting the organic fiber and / or the conductive fiber bundle are filled with the copolyester (A), and the organic fiber and / or the conductive fiber are securely integrated. It is held without detachment, and the subsequent handling becomes good and the workability is improved.

Organic fibers and / or conductive fibers are preferably opened before impregnation. Opening allows the resin to be impregnated smoothly in a short time, and even if the molding conditions change slightly, high impregnation is maintained, and the fibers are uniformly dispersed and the resin impregnates so as to surround each fiber. The existing space is reduced and the number thereof is reduced, and a good impregnation state is obtained.

The organic fiber and / or conductive fiber is preferably untwisted, and thus is easier to open, so the organic fiber and / or conductive fiber is more easily impregnated with the copolymer polyester resin (A), but is twisted. Things can also be used.

The organic fiber and / or the conductive fiber is preferably twisted at a pitch of 35 pitches per 1 m or more at the exit of the die of the impregnation apparatus after impregnation. By winding and twisting fibers that have been loosened or shortly cut in a die, clogging of the orifice caused by these is prevented, and the impregnated resin oozes out to the outside of the fiber bundle. By coating, the shape is adjusted, and there is an effect of protecting the organic fiber and / or the conductive fiber. In addition, by twisting, it is possible to keep the fiber 5 to 10% longer than the pellet length. When this polyester resin composition is blended with a molding resin to form a molded product, there is no twisted polyester resin. Compared to the composition, it is possible to improve mechanical properties or conductivity by about 20% or more. If the number of twists is less than 35 pitches per 1 m in length, fibers loosened or cut short in the die will appear as fluff on the surface of the pellet, causing clogging at the orifice, resulting in quality and Not only is it not preferable in processing, but it becomes difficult to maintain the fiber length in the molded product, and it is impossible to obtain the expected effect on strength, conductivity, and the like.

The filler used in the present invention is preferably processed with the copolyester (A) at a temperature at which the stretchability is not lost.

The filler strand impregnated with the copolymerized polyester (A) is then cut and pelletized by mechanical impact treatment to form a polyester resin composition. This pellet molding process is indispensable for the quantitative supply of the polyester-based resin composition as a filler, and with a resin having an Mw of less than 10,000, it cannot withstand the impact of the pellet molding and falls apart. The shape cannot be maintained. The “pellet” in the present invention refers to a molding material granulated into a small sphere, cylinder, prism or the like having a diameter or side of about 2 mm to 5 mm.

When producing polyester-based resin compositions, flame retardants, flame retardant aids, pigments, dyes, anti-discoloring agents, lubricants, mold release, in addition to the above components, as long as they do not impair the function of the resin composition Agent, compatibilizer, dispersant, crystal nucleating agent, plasticizer, heat stabilizer, antioxidant, weathering agent, anti-coloring agent, ultraviolet absorber, fluidity modifier, foaming agent, antibacterial agent, vibration damping agent Additives such as deodorants, slip agents, slidability modifiers, conductivity-imparting agents, antistatic agents, rigidity-imparting agents, and impact modifiers may be blended.

The filler of the present invention includes a coupling agent such as a silane coupling agent, an aluminate coupling agent, a titanate coupling agent, a urethane resin, an epoxy resin, an ester resin, a styrene resin, an olefin resin, an amide resin. It may be treated with a sizing agent such as a resin, a phenolic copolymer such as terpene / phenol, or a liquid crystalline resin.

The polyester resin composition of the present invention is a master batch. A masterbatch contains a high concentration of filler and dilutes the filler content to a desired concentration with the thermoplastic resin (B), which is a molding resin (uncolored thermoplastic resin), when molding a molded product. The thermoplastic resin composition used as a molded article is said.

The impregnation ratio of the copolyester (A) in the master batch is preferably 10 to 90% by weight. If the amount is less than these ranges, the amount is not sufficient to be impregnated in the filler, and the organic fibers and / or conductive fibers are not bundled as a filler, and the polyester resin composition may not be molded. Moreover, even if an amount exceeding these ranges is used for impregnation, not only the effect according to the amount can be expected, but also the amount of filler in the master batch is relatively reduced, and the physical properties of the molded product are enhanced and the conductivity is increased. There is a risk that the effect of.

In order to suppress mechanical damage of the organic fiber and / or conductive fiber as a filler during molding, the masterbatch and the thermoplastic resin (B) are not melt-kneaded in advance, and a direct injection molding machine or It is desirable to perform molding in which the molding process of melt mixing is performed for the first time in each of the extruders. Further, in the molding machine, it is required that organic fibers and / or conductive fibers are quickly and uniformly dispersed in the thermoplastic resin (B). Therefore, it is preferable that the melting point or softening point of the copolymerized polyester (A) impregnated in the organic fiber and / or conductive fiber bundle as the filler is equal to or lower than the melting point or softening point of the thermoplastic resin (B).

The thermoplastic resin (B) used in the present invention is compatible with the copolymer (A). For example, polyamide (Nylon 6, Nylon 66, Nylon 11, Nylon 12, Nylon 610, Nylon 612, Nylon 6I, Nylon 6T, Nylon 9T, etc.), copolyamides thereof (including liquid crystalline polyamide), polyester (polyethylene terephthalate) , Polybutylene terephthalate, etc.) and their copolyester (including liquid crystalline polyester), polycarbonate, acrylonitrile / butadiene / styrene copolymer (ABS), acrylonitrile / styrene copolymer (AS), polyolefin (polyethylene, polypropylene, etc.) ), Polystyrene, polyetherimide, polysulfone, polyethersulfone, polyphenylene sulfide, polyphenylene oxide, polyetheretherketone, polyaceta Etc. Le and a polymer alloy comprising a combination thereof, can be used almost all thermoplastic resins. Among them, preferred are resins containing an aromatic ring in the main skeleton, such as polyamide, polycarbonate, ABS, polyphenylene oxide, polyphenylene sulfide, and liquid crystal polyester, which are used as engineering plastics. They can also be used for aliphatic resins such as polyolefins.

Further, depending on the necessity of improving impact resistance, one or more kinds of mixtures selected from elastomers such as olefin copolymers, polyester polyether elastomers, polyester polyester elastomers may be added to obtain desired properties. It is also possible to use a resin further imparted with Furthermore, these copolymers and a resin in which two or more kinds are mixed can also be used in the present invention in accordance with necessary properties such as moldability, heat resistance and low water absorption. In addition, for the purpose of improving impact resistance, etc., a resin in which an elastomer or a rubber component is added to the above resin, and a terminal group modified and sealed for compatibility control when the resin is mixed, It is included in the present invention.

In the polyester resin composition, the blending ratio of the filler impregnated with the copolyester (A) varies depending on the intended use of the molded product, but the filler is 10 to 90% by weight, particularly 15 to 70% by weight. preferable. If it is less than 10% by weight, the mechanical properties and electrical conductivity of the molded product cannot be obtained, and if it exceeds 90% by weight, the impregnation property becomes insufficient, and the molded product is not preferable because of defects such as poor dispersion and warpage.

In the polyester resin composition, the proportion of the molded product to the thermoplastic resin (B) is preferably 30 to 85% by weight, particularly preferably 60 to 80% by weight. If it is less than 30% by weight, the fluidity of the resin is deteriorated to cause molding failure. If it exceeds 85% by weight, the mechanical properties of the molded product cannot be obtained, which is not preferable.

Further, when molding the molded resin by blending the polyester-based resin composition of the present invention with the thermoplastic resin (B), a heat-resistant stabilizer, a weathering agent, and a lubricant as necessary as long as the functions of the molded product are not impaired. Additives such as slip agents, flame retardants, nucleating agents, pigments and dyes may be blended.

The use of the molded product in the present invention includes a member for electronic / electric equipment that requires molding property and mechanical characteristics (particularly rigidity) in a thin molded product. Since the molded article of the present invention can achieve high rigidity, light weight, electromagnetic wave shielding, and the like, it is effective for applications such as a housing for portable electronic / electric equipment. More specifically, it is preferred for housings such as large displays, notebook computers, portable telephones, PHS, PDAs (portable information terminals such as electronic notebooks), video cameras, digital still cameras, and portable radio cassette players. used.

In addition, when the filler is a conductive fiber, the filler-containing thermoplastic resin resuscitation has high conductivity, so that it can be imparted with charge / discharge prevention properties by adding a small amount, and these characteristics are necessary. The present invention is also useful for application to members such as IC trays and baskets for carrying silicon wafers.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited by this. In the examples, “part” means “part by weight” and “%” means “% by weight”.

(Example 1) terephthalic acid: 166 parts, isophthalic acid: 166 parts, ethylene oxide adduct of 4,4′-dihydroxydiphenyl-2,2-propane: 284 parts, ethylene glycol: 162 parts, manganese acetate tetrahydrate 0.25 parts of the product was charged into a reactor, and reacted under stirring at 240 ° C. for 3 hours at normal pressure under a nitrogen atmosphere. Next, the reaction was performed at a heating temperature of 260 ° C. for 3 hours. Methanol produced by this reaction was always distilled out of the system.

Next, 0.24 parts by weight of a mixture solution of germanium dioxide and ethylene glycol in a weight ratio of 1:10 was added to the reaction system, stirred for 20 minutes, and then 0.08 parts by weight of phosphoric acid was added and reacted for 1 hour. . Thereafter, the temperature was raised to 280 ° C. over 1 hour, the pressure in the system was reduced to 1 Torr, and the reaction was further continued for 4 hours, and excess ethylene glycol was distilled off from the system. After completion of the reaction, the reaction product was melt-extruded in a strand form outside the reactor, immersed in water and cooled, and then cut into a pellet by a strand cutter.

The copolymerization ratio of the copolymer polyester (1) obtained by the above liquid phase polymerization was analyzed by a nuclear magnetic resonance apparatus JMN-LA400 (13C-NMR) manufactured by JEOL Ltd. As a result, terephthalic acid: 25 mol%, Isophthalic acid: 25 mol%, ethylene oxide adduct of 4,4′-dihydroxydiphenyl-2,2-propane: 25 mol%, ethylene glycol: 25 mol%.

Moreover, it was 20000 when the weight average molecular weight (Mw) was measured with the high temperature GPC alliance system (made by Waters). The melt viscosity was 550 dPa · s as measured with a capillary flow test test apparatus Capillograph 1D (manufactured by Toyo Seiki Co., Ltd.). The melting point was measured with a differential scanning calorimeter DSC SSC5200 (manufactured by Seiko Instruments Inc.), and the melting point was 74 ° C. The results are shown in Table 4.

Copolymer polyesters (2) to (6) were prepared in the same manner as copolymer polyester (1), and the results are shown in Table 4.

Copolymerized polyester resin (1) prepared above is heated and melted, and 75% of stainless fiber impregnated with 25% (fiber diameter: 8 μm, fiber bundle: 12,000) is made into a strand and cut with a pelletizer to obtain a length. A pellet master batch (polyester resin composition) having a pitch of 6 mm and a pitch of 40 pitches was obtained. At this time, a master batch having good impregnation and coating properties could be obtained.

(Comparative Example 1) 75% of the stainless steel fiber of the filler cut to 6 mm and shortened to fiber and 25% of the copolyester (1) were blended and mixed and stirred with a Henschel mixer-150L (Mitsui Miike Chemical Co., Ltd.). After that, melt-kneading with a twin screw co-rotating screw extruder having a screw diameter of 40 mm and an L / D value of 42, the strand is cut with a pelletizer, and a pellet-shaped filler-containing thermoplastic resin composition having a length of 6 mm I got a thing. Although it was a master batch with good impregnation and coating properties, the strands were not stable when twisting more than 20 pitches, so the number of twists was 15 pitches.

(Comparative example 2) The composition of Example 1 was changed to 8% for stainless steel fiber and 92% for copolyester resin (1), and in the same manner as in Example 1, a pellet master batch (polyester resin) Composition) was obtained. Although it was a master batch with good impregnation and coating properties, the strands were not stable when twisting more than 35 pitches, so the number of twists was 30 pitches. The molding experiment was stopped because the concentration was too low.

(Comparative Example 3) Instead of the copolyester resin (1) used in Example 1, copolyester resin (2) (terephthalic acid: 30 mol%, isophthalic acid: 20 mol%, 4,4'-dihydroxydiphenyl- Except for using 2,2-propane ethylene oxide adducts: 25 mol%, ethylene glycol: 25 mol%), the strands were formed in the same manner as in Example 1 and cut into a length of 6 mm with a pelletizer. At this time, slight pulsation occurred and slight fluffing was observed, but a masterbatch could be created without any problem in cutting.

(Comparative Example 4) Instead of the copolyester resin (1) used in Example 1, copolyester resin (3) (terephthalic acid: 25 mol%, isophthalic acid: 25 mol%, 1,4-butanediol: 45 mol) %, Ethylene glycol: 5 mol%) was used in the same manner as in Example 1 except that a strand was formed, and a 6 mm length was cut with a pelletizer. At this time, a slight pulsation occurred, but a masterbatch could be created without any problem in cutting.

(Comparative Example 5) Instead of the copolyester resin (1) used in Example 1, the copolyester resin (4) having the same composition and low molecular weight as the copolyester resin (1) (terephthalic acid: 25 mol%, In the same manner as in Example 1 except that isophthalic acid: 25 mol%, 4,4′-dihydroxydiphenyl-2,2-propane ethylene oxide adduct: 25 mol%, ethylene glycol: 25 mol%) was used. The 6 mm length was cut with a pelletizer. At this time, slight pulsation and blocking occurred, but there was no problem in cutting, and a master batch could be created.

(Comparative Example 6) Instead of the copolyester resin (1) used in Example 1, copolyester resin (5) (terephthalic acid: 35 mol%, isophthalic acid: 15 mol%, 1,4-butanediol: 30 mol %, Ethylene glycol: 20 mol%) was used in the same manner as in Example 1 except that a strand was formed, and a 6 mm length was cut with a pelletizer. At this time, slight pulsation occurred and slight fuzz was observed, but a masterbatch could be created without any problem in cutting.

(Comparative Example 7) Instead of the copolymer polyester resin (1) used in Example 1, an attempt was made to impregnate in the same manner as in Example 1 except that 25% of polycarbonate was used. The experiment was stopped.

(Comparative Example 8) Instead of the copolymer polyester resin (1) used in Example 1, an attempt was made to impregnate in the same manner as in Example 1 except that 25% polyamide was used. The experiment was stopped.

(Example 2) Instead of the copolyester resin (1) used in Example 1, copolyester resin (6) (terephthalic acid: 30%, isophthalic acid: 20%, 4,4'-dihydroxydiphenyl- Except for using 2,2-propane ethylene oxide adducts: 30 mol%, propylene glycol: 20 mol%), it was made into a strand in the same manner as in Example 1 and filled in pellets with a length of 6 mm and a pitch of 42 pitches. A material-containing thermoplastic resin composition was obtained. At this time, a master batch having good impregnation and coating properties could be obtained.

(Example 3) Instead of the copolyester resin (1) used in Example 1, copolyester resin (7) (copolyester resin (2) / copolyester resin (3) = 50/50 In the same manner as in Example 1 except that the blend, 4,4′-dihydroxydiphenyl-2,2-propane ethylene oxide adduct: 12.5 mol% in the resin was used, a strand was formed and the length was 6 mm. A filler-containing thermoplastic resin composition having a pellet number of 40 pitches was obtained. At this time, a master batch having good impregnation and coating properties could be obtained.

(Examples 4 to 17) Instead of the stainless steel fibers used in Example 1, various fibers as shown in Table 3 (carbon fibers, Ni-coated carbon fibers, Ag-coated polyester fibers, Cu-coated aramid fibers, Ni-coated aramid fibers) Polypropylene fiber, acrylic fiber, polyester fiber, aramid fiber, nylon fiber, polybenzoxazoline fiber, cotton fiber, hemp fiber, kenaf fiber) 60% and copolymer polyester (1) 40%, and Example 1 Similarly, it was made into a strand shape, and a pellet-containing filler-containing thermoplastic resin composition having a length of 6 mm and a twist number of 35 pitches or more was obtained. At this time, a master batch having good impregnation and coating properties could be obtained.

(Comparative Examples 9-22) Compound pellets were prepared in the same manner as in Comparative Example 1 using the blending systems of Examples 4-17. At this time, if the twist is more than 20 pitches, the strands are not stable, so the number of twists is less than 20 pitches.

Table 1 shows the blending contents and the production method for the polyester resin compositions of Examples 1 to 17 and Comparative Examples 1 to 22 (however, Comparative Example 7: polycarbonate, Comparative Example 8: polyamide).

For the polyester resin compositions of Examples 1 to 17 and Comparative Examples 1 to 22 (however, Comparative Example 7: Polycarbonate, Comparative Example 8: Polyamide), Table 3 shows the types of fibers and types of copolyesters, respectively. This is shown in FIG.

About the polyester-type resin composition of Examples 1-16 and Comparative Examples 1-19 (however, Comparative Example 7: Polycarbonate, Comparative Example 8: Polyamide), the thermoplastic resin (B) shown in Table 5 was used. The following (1) to (4) were evaluated, and the results are shown in Table 2.

[Productivity evaluation]
(1) Evaluate productivity at the time of manufacture of a polyester-type resin composition (masterbatch).
○: Impregnation is sufficient, and it can be produced smoothly without causing pulsating flow or fluffing of strands.
Δ: Slight pulsation and fluffing occur, but impregnation and cutting are good and production is possible.
X: Impregnation is insufficient, and fluffing or blocking occurs in the strand, making it impossible to produce.
(2) The number of twists at the time of manufacture of a polyester-type resin composition (masterbatch) is evaluated by the pitch number per 1 m. When the pitch is 35 pitches or more, there is almost no clogging of the orifice at the die outlet and no fuzz of the strands.

[Evaluation of Sheet Molded Product] The thermoplastic resin (B) shown in Table 2 was mixed with the polyester resin composition (masterbatch) so that the filler concentration was 10%. These are each melt-extruded at a molding temperature of 290 ° C. (when the thermoplastic resin (B) is polycarbonate <PC> or polyethylene terephthalate <PET>) at a rotational speed of 60 rpm using a T-die film molding machine (manufactured by Toyo Seiki). A sheet-like molded product having a thickness of 100 μm was obtained, and (3) the sheet state was evaluated according to the following criteria. The results are shown in Table 2.

(3) Sheet condition evaluation (visual evaluation of film cracks, bumps, protrusions, smoothness, etc.)
○: Very good, no problem in practical use.
Δ: Slight surface roughness was observed and smoothness was difficult, but there was no problem in practical use.
X: Not only is there a problem in workability, but there is a problem in any of film cracking, peeling, fluttering, and pinholes due to poor dispersion, which is defective.
−: The test was not performed.

[Evaluation of Injection Molded Product] As in (3), each of the thermoplastic resins (B) shown in Table 5 was mixed so that the filler concentration would be 10%, and the injection molding machine IS100F1 (manufactured by Toshiba Machine Co., Ltd.) Back pressure 0 kg / cm 2, molding temperature 290 ° C. (when the thermoplastic resin (B) is polycarbonate <PC>, polyphenylene ether <PPE> or polyphenylene sulfide <PPS>), 250 ° C. (thermoplastic resin (B) polypropylene <PP>) and 220 ° C. (when the thermoplastic resin (B) is an acrylonitrile / butadiene / styrene copolymer <ABS>) were injection molded to obtain a plate. With respect to the obtained plate, (4) surface layer state of molded plate, (5) mechanical property retention ratio, (6) conductivity and (7) electromagnetic wave shielding property were evaluated according to the following criteria, and are shown in Table 2.

(4) Evaluation of surface state of molded plate (visual evaluation of flash, silver, cracks, bumps, protrusions, smoothness, etc.)
○: Silver and flash are not generated, and appearance and smoothness are very good.
Δ: Silver or flash is not generated, but either appearance or smoothness is difficult.
X: There is a problem with any of flash, silver, cracks, bumps, protrusions and smoothness. Bad.
−: The test was not performed.

(5) Evaluation of mechanical property retention rate of molded plate Obtain test values for three mechanical properties of each plate: tensile strength (ASTM D638), flexural modulus (ASTM D790), and Izod impact (ASTM D256). The value of the plate made only of the plastic resin (B) was taken as 100%, and the physical property retention rate of each plate was determined.
○: Retention rate of tensile strength: 150% or more, retention rate of flexural modulus: 200% or more and retention rate of Izod impact value (for PC: 50% or more, for PPE, PPS: 60% or more, ABS Case: 80% or more, PP: 100% or more)
Δ: When the retention rate of the test value does not satisfy the above conditions.
X: When the retention rate of 2 test values or more does not satisfy the above conditions.
−: The test was not performed.

(6) Conductivity evaluation (volume resistance value)
A test piece having a width of 50 mm, a length of 75 mm, and a thickness of 3 mm of each injection-molded plate was subjected to measurement in an absolutely dry state (moisture content of 0.1% or less). First, a conductive paste is applied to a length × thickness surface having two surfaces, and the conductive paste is sufficiently dried, and then both surfaces are pressure-bonded to electrodes, and an electric resistance value between the electrodes is measured by Wheatstone Bridge Type 2755 ( Measured by Yokogawa Electric Corporation). For one sample, the flow direction and the two directions perpendicular to the flow were measured, and the average value was obtained for each sample to obtain the volume specific electrical resistance value (unit: Ω · cm). A value of 103 Ω · cm or less is a guideline for good conductivity.
Volume resistivity calculation method δ = R · S / L (where δ: volume resistivity, R: measured electric resistance, S: cross-sectional area of test piece, L: length between electrodes)

(7) Electromagnetic shielding (transmission attenuation rate)
A 3 mm thick flat plate of each of the injection-molded plates was measured for attenuation by the flat plate when irradiated with an electromagnetic wave of 10 KHz to 3 GHz in a shield box of a spectroanalyzer FSEA30 (manufactured by Lord Schwartz) (advantest method). The attenuation measurement value was expressed in decibels (unit dB), and Table 2 shows a numerical value of 500 MHz in the microwave region. Generally, it is said that there is an electromagnetic wave shielding property if it is 30 dB (about 97% cut) or more, and if it is 40 dB (99% cut) or more, there is no problem.

Claims (5)

The content of ethylene oxide adduct of 4,4′-dihydroxydiphenyl-2,2-propane is 10 to 40 mol%,
Copolymerized polyester (A) having a weight average molecular weight of 10,000 to 30,000 is impregnated into a long fiber having a fiber diameter of 4 to 20 μm as a filler by a melt drawing method, and the long fiber is 10 to 10% of the total composition. A polyester resin composition comprising 90% by weight , comprising:
The long fiber is stainless fiber, carbon fiber, Ni-coated carbon fiber, Ag-coated polyester fiber, Cu-coated aramid fiber, polypropylene fiber, acrylic fiber, polyester fiber, aramid fiber, nylon fiber, polybenzoxazoline fiber, cotton fiber hemp fiber And a polyester resin composition characterized by being one or more organic fibers or conductive fibers selected from kenaf fibers. The polyester resin composition according to claim 1, wherein the dicarboxylic acid component of the copolyester (A) is terephthalic acid and isophthalic acid. The polyester resin composition according to claim 1 or 2, wherein the copolymerized polyester (A) has a melt viscosity at 200 ° C measured in accordance with JIS K7199 of 10,000 dPa · s or less. The polyester resin composition according to any one of claims 1 to 3, wherein the long fiber includes a twist of 35 pitches or more and 45 pitches or less per 1 m of length. A polyester resin composition according to any one of claims 1 to 4 , and a thermoplastic resin (B) selected from the group consisting of polyethylene terephthalate, polycarbonate, polyphenylene ether, polyphenylene sulfide, and acrylic, butadiene, and styrene. Molding.