KR20000017460A - Fiber-reinforced polyester resin molding material and its production process and molded product - Google Patents

Abstract

PURPOSE: A fiber-strengthened polyester resin forming material is provided to facilitate extrusion, hollow or foaming forming. CONSTITUTION: The fiber-strengthened polyester resin forming material has a ratio of extensional viscosity to shear viscosity from 15 to 40 measured with a capillary viscometer at 280°C and at the shear rate of 100 s¬(-1). The polyester resin forming material has a shear viscosity of 10 to 50 kPa.s measured with a capillary viscometer at 280°C and at the shear rate of 100 s¬(-1).

Description

Fiber-reinforced polyester resin molding material and its production process and molded product

The present invention relates to a fiber-reinforced polyester resin molding material, a production method thereof and a molded article thereof.

The so-called fiber-reinforced polyester resins produced by mixing polyester resins with reinforcing fibers are more excellent in heat resistance and impact resistance than conventional polyester resins. On the other hand, when this fiber-reinforced polyester resin is used for extrusion molding or blow molding, there is a problem of draw down of the resin because the molecular weight of the resin is not sufficient. In addition, when the fiber-reinforced polyester resin is applied to foam molding, there is a problem that a uniform precision foamed product cannot be obtained because of low resin viscosity. Therefore, conventional injection molding is mainly performed. However, injection molding has a problem in that a mold used is relatively expensive and a molded article to be produced is limited. Moreover, for molded articles produced from injection molding, because the molecular weight of the resin is insufficient, the mechanical properties of the molded article are insufficient, and therefore their use is limited.

Accordingly, there is an attempt to improve the moldability of the fiber-reinforced polyester resin and the mechanical properties of the resulting molded article by increasing the molecular weight of the fiber-reinforced polyester resin. For example, when melt-kneading a polyester resin, there is an attempt to increase the molecular weight by adding a polyvalent compound which can extend the polymer chain by reacting at the end group of the polyester resin (JP-B-013860 / 1972). JP-A-276820 / 1990, JP-A-506056 / 1993). However, this method suffers from the following problems: For example, when polyepoxy compounds or polyisocyanates are used, excessive three-dimensionalization occurs in the polymer chain extension reaction, so that a molded article having a very non-uniform thickness is obtained, resulting in fracture or local extension. Resulting in; In addition, when polyacid anhydride is used, three-dimensionalization tends to occur easily, but not as much as the above-described epoxy compound or isocyanate, and thus it may be difficult to maintain stable kneading conditions for a long time.

In the method disclosed in JP-A-509776 / 1996, in order to solve the above-mentioned problems, the glass-fiber-reinforced polyethylene terephthalate (GF-PET) and the polyhydric compound are melt-kneaded for a short period of time to undergo a chain extension reaction during melt-kneading. Attempts were made to mold the resulting pellets and subject the resulting molded articles to a solid state polyaddition reaction to increase the molecular weight. However, this method requires an oven to process the molded article because the molded article is subjected to the solid state polyaddition reaction, and thus there is a problem in that the production cost is high and the size of the molded article is limited.

SUMMARY OF THE INVENTION An object of the present invention is a fiber-reinforced polyester resin molding material which can facilitate a molding process such as extrusion, blow molding, or foam molding, which has problems when using a conventional fiber-reinforced polyester resin molding material, and It is to provide a manufacturing method and a molded article thereof, and more preferably can also be used for injection molding than conventional, it can be further provided a molded article excellent in mechanical properties.

1 is a cross-sectional view of a two-barrel capillary viscometer.

The present inventors have studied diligently to solve the above problems. As a result, they are inherent to fiber-reinforced polyester resins, and the extensional and shear viscosities measured by specific methods reflect not only the moldability of the fiber-reinforced polyester resin, but also the mechanical properties of the resulting molded article. It is characteristic: If the ratio of elongational viscosity to shear viscosity is in a certain range or the elongational viscosity is in a certain range, the moldability of the molding material is excellent, in particular, in extrusion or blow molding, the moldability is good without sagging and foaming It is possible to obtain a uniform precision foamed product by molding, and to obtain a molded article having excellent mechanical properties and appearance by the above-described molding process and injection molding; When a specific production method is used for the mixture containing the polyester resin and the polycarboxylic anhydride, the molding material of the above object can be easily obtained; Using the molding material, the present invention was found to be easy to control the temperature during molding and to enable the molding process at a high cost performance ratio.

Therefore, the fiber-reinforced polyester resin molding material according to the present invention has a ratio (λ / η) of elongation viscosity (λ) to shear viscosity (η) as measured by a capillary viscometer at 280 ° C. and a shear rate of 100 s ⁻¹ . It is characterized by the range of 40.

In addition, another fiber-reinforced polyester resin molding material according to the present invention is characterized by an elongation viscosity (λ) of 10 to 50 kPa · s as measured by a capillary viscometer at 280 ° C. and a shear rate of 100 s ⁻¹ .

In addition, the method for producing a fiber-reinforced polyester resin molding material according to the present invention comprises the steps of melt-kneading a mixture comprising a polyester resin and a polycarboxylic acid anhydride; And then performing a solid state polyaddition reaction of the melt-kneaded mixture.

The molded article according to the invention is also obtained by a method comprising the step of molding the fiber-reinforced polyester resin molding material according to the invention.

These and other objects and advantages of the present invention will become more apparent from the following detailed examples.

(Fiber-reinforced polyester resin molding material):

The fiber-reinforced polyester resin molding material according to the present invention is a molding material further comprising other components such as fiber-reinforced polyester resin and, if necessary, additives. As the reinforcing material, the fiber-reinforced polyester resin may be a mixture of polyester resin and reinforcing fiber, but as mentioned below, preferred fiber-reinforced polyester resin is a polyhydric compound when other components such as additives are added. The molecular weight is increased by the reaction. For reference, the reinforcing fibers used in the present invention are not particularly limited, but examples thereof include glass fibers, aramid fibers and carbon fibers. In particular, glass fibers are preferred, and chopped glass fibers are more preferred. The amount of reinforcing fibers to be added is not particularly limited, but their amount is preferably in the range of 5 to 50% by weight, more preferably 10 to 45% by weight of the polyester resin. The amount in the aramid fibers or carbon fibers is 2 to 50% by weight of the polyester resin, more preferably 5 to 45% by weight. The length of the fiber is not particularly limited as long as it is conventionally used, but is preferably in the range of 0.1 to 5 mm, more preferably in the range of 0.2 to 4 mm.

The polyester resin used in the present invention is a product of a polycondensation reaction between dicarboxylic acid or a derivative thereof and diol having 2 to 12 carbon atoms.

The dicarboxylic acids or derivatives thereof are not particularly limited, but examples thereof include: phthalic acid, terephthalic acid, isophthalic acid, chloroterephthalic acid, nitroterephthalic acid, 5-sodiumsulfoisophthalic acid, and anhydrides thereof and dimethyl Diesters of lower alcohols such as esters or diethyl esters; Diesters of 2,6-naphthalenedicarboxylic acids and their anhydrides and lower alcohols such as dimethyl ester or diethyl ester; Also diesters of hexahydrophthalic acid, hexahydroterephthalic acid, adipic acid, sebacic acid, and anhydrides thereof and lower alcohols such as dimethyl ester or diethyl ester. In particular, terephthalic acid is preferable. The diol is not particularly limited, but examples thereof include ethylene glycol, 1,4-cyclohexanediol and 1,4-butanediol. In particular, ethylene glycol is preferable.

Also included in the polyester resin are copolymers in which units derived from isophthalic acid or another dicarboxylic acid are replaced with up to 25 mole% of units derived from terephthalic acid. Particularly preferred are polyalkylene-terephthalate polymers produced by homopolymerization of polyalkylene terephthalates or copolymerization of polyalkylene terephthalates with isophthalic acid. In addition, the polyester resin may further include a thermoplastic resin structure in addition to the polyester structure. Preferred examples of polyester resins include: polyethylene terephthalate (hereinafter referred to as PET); PET having a portion copolymerized with isophthalic acid; Polybutylene terephthalate; And polyethylene naphthalate. In particular, PET is preferable.

This polyester resin may be mixed with another compatible polymer such as polycarbonate or polycaprolactone in a ratio of up to 20% by weight. Furthermore, the mechanical property can be improved by showing liquid crystallinity and adding the polymer or compound which has a reactive group (for example, hydroxyl and amino) in the ratio of 5 weight% or less.

The fiber-reinforced polyester resin molding material according to the present invention further comprises a mixture of the above-described polyester resin and the above-mentioned fibers and, if necessary, other components such as additives. As mentioned below, preferred fiber-reinforced polyester resins have an increased molecular weight by reaction with polyhydric compounds.

Examples of said other components, such as an additive added to resin as needed, include: polyolefins, such as polyethylene, a polypropylene, and polybutylene; And other thermoplastic resins such as vinyl chloride resin, polyvinyl acetal, polyvinyl alcohol, polystyrene, AS resin, ABS resin, polyamide, polycarbonate and thermoplastic elastomer; Fillers such as calcium carbonate and talc; And additives such as crystal-nucleating agents, crystal promoters, plasticizers, antioxidants, stabilizers, pigments, flame retardants and release agents.

When polyolefins are included as such other components, such as additives, specific examples of polyolefins include polyethylene, polypropylene, polybutylene, copolymers thereof, and mixtures of these homopolymers and / or copolymers. In particular, polyethylene, polypropylene, copolymers thereof, and mixtures of these homopolymers and / or copolymers are preferable, and polypropylene is more preferable. The molecular weight of the polyolefin is preferably in the range of 5,000 to 1,000,000, more preferably in the range of 10,000 to 100,000. The amount of the polyolefin added is preferably in the range of 0.05 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, particularly preferably 0.2 to 2 parts by weight per 100 parts by weight of the polyester resin.

In addition, the ratio of the polyester resin in the present invention is not particularly limited, but is preferably in the range of 30 to 100 parts by weight, more preferably 50 to 90 parts by weight per 100 parts by weight of the total molding material of the present invention.

The fiber-reinforced polyester resin molding material according to the present invention has a ratio (λ / η) of elongation viscosity (λ) to shear viscosity (η) of 15 to 40 as measured by a capillary viscometer at 280 ° C. and a shear rate of 100 s ⁻¹ . It is a range. The ratio (λ / η) is preferably 20 to 40, more preferably 25 to 40.

Fiber-reinforced polyester resin moldings having a ratio (λ / η) of extensional viscosity (λ) to shear viscosity (η) as measured in capillary viscometer at a shear rate of 100 s ⁻¹ in the range of 15 to 40 ranged from 15 to 40 It is excellent, in particular in extrusion or blow molding, the resin does not sag and the moldability is good, and it is possible to provide a uniform precision foamed product by foam molding, and also the mechanical properties and appearance by the molding process and injection molding This excellent molded article can be provided. In addition, by using the molding material, it is easy to control the temperature during molding, and the molding process is possible at a high cost performance ratio. When the ratio (λ / η) of the elongational viscosity (λ) to the shear viscosity (η) is less than 15, extrusion or blow molding causes the extruded resin to withstand its own weight and sag or have sufficient elongation. It is disadvantageous in that it is difficult to obtain a uniform, precise foamed product when the thickness is uneven or tearing occurs and foaming is performed. Further, when the ratio (λ / η) of the elongation viscosity λ to the shear viscosity η is greater than 40, it is disadvantageous in that, for example, moldability or properties of the formed molded article are deteriorated.

In addition, another fiber-reinforced polyester resin molding material according to the present invention is characterized by an elongation viscosity (λ) of 10 to 50 kPa · s as measured by a capillary viscometer at 280 ° C. and a shear rate of 100 s ⁻¹ . Said elongation viscosity ((lambda)) becomes like this. Preferably it is 15-50 kPa * s, More preferably, it is the range of 20-40 kPa * s.

Fiber-reinforced polyester resin moldings having an elongational viscosity (λ) of 10 to 50 kPa · s as measured by capillary viscometer at 280 ° C. and shear rate of 100 s ⁻¹ have excellent moldability, especially in extrusion or blow molding. Formability is satisfactory without sag, and it is possible to provide a uniform precision foamed product by foam molding, and also to provide a molded article excellent in mechanical properties and appearance by the molding process and injection molding. In addition, by using the molding material, it is easy to control the temperature during molding, and the molding process is possible at a high cost performance ratio. When the elongation viscosity (λ) is less than 10 kPa · s, extrusion or blow molding may not extrude the resin so that it cannot tolerate its own weight and sag or exhibit sufficient elongation, so that the thickness is uneven or tare. It is disadvantageous in that it is difficult to obtain a uniform and precise foamed product when a ring is generated and foaming is performed. Moreover, when the said extension viscosity (lambda) is larger than 50 kPa * s, it is disadvantageous in the point that moldability or the characteristic of the produced molded article fall, for example.

The fiber-reinforced polyester resin molding material according to the present invention is amorphous, and the resulting amorphous resin molding material is measured by analyzing by DSC (differential scanning calorimetry) at a heating rate of 10 ° C./min. It is a resin molding material whose temperature is 115 degreeC or more. When the melt-extruded resin is molded by cooling in the extrusion, blow molding, or foam molding, an appropriate crystallization rate for the resin molding material is required. In other words, if the crystallization rate is very fast, crystallization proceeds during molding, and it is disadvantageous in that it cannot be molded completely, and thus a preferable molded article cannot be obtained. Even if a molded article is obtained, it has a large internal strain and a good molded article cannot be obtained. Therefore, the resin molding material was amorphous, and the resulting amorphous resin molding material was measured by DSC at a heating rate of 10 ° C./min and measured, and when the cooling crystallization temperature was 115 ° C. or higher (preferably 120 to 140 ° C.), The crystallization rate in the temperature range can provide a good molded article. If the cooling crystallization temperature is lower than 115 ° C., the crystallization rate is so fast that crystallization proceeds during molding, and thus a preferable molded article cannot be obtained. On the other hand, if the crystallization rate is very slow, ultra high temperature or very long processing time is required when the molding material is finally crystallized, or even if the molding material is crystallized, crystallinity does not increase sufficiently to obtain sufficient rigidity. none. Therefore, as mentioned above, 140 degrees C or less is a more preferable range.

The fiber-reinforced polyester resin molding material according to the invention preferably has an intrinsic viscosity (IV) of 0.6 to 1.8 (dl / g) before use for molding. If the intrinsic viscosity is less than 0.6 (dl / g), the moldability is poor, and the resulting molded article has only low mechanical properties. When the intrinsic viscosity is larger than 1.8 (dl / g), the viscosity dependence on temperature is too large, which is disadvantageous in that a safe molding operation is difficult. For reference, the molecular weight-increasing reaction using the polyhydric compound mentioned below can easily provide the preferred molecular weight mentioned above.

(Polyvalent compound):

(1) the ratio of elongation viscosity (λ) to shear viscosity (η) measured at a capillary viscometer at 280 ° C. at a shear rate of 100 s ⁻¹ in the range of 15 to 40, or (2) at 280 ° C. at a shear rate of 100 s ⁻¹ . The fiber-reinforced polyester resin molding according to the invention, characterized in that the elongation viscosity (λ) is 10 to 50 kPa · s as measured by a capillary viscometer, is particularly preferably added with a polyhydric compound to effect chain extension reaction. It contains the polyester resin by which molecular weight increases. The polyhydric compound that can be used in the present invention is preferably selected from the group consisting of diepoxy compounds, bisoxazolin compounds, polyisocyanate compounds and aromatic tetracarboxylic dianhydrides. However, polycarboxylic anhydride is particularly preferred in order to obtain the resin molding material according to the present invention effectively. Moreover, aromatic tetracarboxylic dianhydrides, in particular pyromellitic dianhydride, are the most preferred polycarboxylic anhydrides. Examples of other useful dianhydrides include 3,3 ', 4,4'-diphenyltetracarboxylic acid, (perylene-3,4,9,10) tetracarboxylic acid, 3,3', 4,4'- Benzophenonetetracarboxylic acid, 2,2-bis (3,4-dicarboxyphenyl) propane, bis (3,4-dicarboxyphenyl) ether, bis (3,4-dicarboxyphenyl) sulfone, 1,2 , 3,4-cyclobutanetetracarboxylic acid and 2,3,4,5-tetracarboxyhydrofuran. The amount of the polyvalent compound to be used is usually in the range of 0.05 to 2 parts by weight per 100 parts by weight of the polyester resin.

(Melt-kneading):

As described above, (1) the ratio (λ / η) of extensional viscosity (λ) to shear viscosity (η) measured in a capillary viscometer at 280 ° C. and shear rate of 100 s ⁻¹ ranges from 15 to 40, or ( 2) The fiber-reinforced polyester resin molding material according to the invention, characterized in that the elongation viscosity (λ) is 10 to 50 kPa · s as measured by a capillary viscometer at 280 ° C. and a shear rate of 100 s ⁻¹ , is multivalent. It includes a polyester resin which performs a chain extension reaction by adding a compound and whose molecular weight increases. In particular, however, the fiber-reinforced polyester resin molding material comprises a resin obtained by a process comprising the step of melt-kneading a mixture of a polyester resin and a polycarboxylic acid anhydride. Since the chain extension reaction of the polyester resin and the polycarboxyl anhydride provides a fiber-reinforced polyester resin of increased molecular weight, the molding material of the present invention including this resin readily exhibits the above-described effects of the present invention.

If melt-kneading is carried out, other components described above may be added as necessary. Examples of other components include: polyolefins such as polyethylene, polypropylene, and polybutylene; And other thermoplastic resins such as vinyl chloride resin, polyvinyl acetal, polyvinyl alcohol, polystyrene, AS resin, ABS resin, polyamide, polycarbonate and thermoplastic elastomers; Fillers such as calcium carbonate and talc; And crystal-nucleating agents, crystallization promoters, plasticizers, antioxidants, stabilizers, pigments, flame retardants and release agents.

For example, even if the intrinsic viscosity of the polyester resin is increased by melt-kneading or the solid state polyaddition reaction mentioned below, the moldability is greatly improved and molding can be performed under moderate conditions such as molding temperature. It is preferable that polyolefin is contained as said other component. As noted above, embodiments of polyolefins include polyethylene, polypropylene, polybutylene, copolymers thereof, and mixtures of these homopolymers and / or copolymers. In particular, polyethylene, polypropylene, copolymers thereof, and mixtures of these homopolymers and / or copolymers are preferable, and polypropylene is more preferable. The molecular weight of the polyolefin is preferably in the range of 5,000 to 1,000,000, more preferably 10,000 to 100,000. The amount of the polyolefin added is preferably in the range of 0.05 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, particularly preferably 0.2 to 2 parts by weight per 100 parts by weight of the polyester resin.

The melt-kneading is preferably carried out by melt dispersion kneading with a 2-screw extruder.

These twin screw extruders are not particularly limited, but examples of these include: co-rotating intermeshng twin screw extruders with vents, co-rotating non-engaging twin screw extruders with vents, Back-rotating non-engagement twin-screw extruder with exhaust, Back-rotation non-engagement twin-screw extruder with exhaust, Co-rotation non-venting twin-screw extruder without exhaust, Co-rotation non-engagement without exhaust Twin-screw extruder, non-venting counter-rotating twin-screw extruder, exhaust-free counter-rotating non-engaging twin-screw extruder. Of these, the reverse-rotation non-engagement twin-screw extruder equipped with the exhaust port is particularly preferred. In addition, the melt-kneading temperature depends on the melting point of the polymer or copolymer used, but is preferably in the range of 240 to 300 ° C. The residence time in the extruder is also preferably in the range of 10 to 100 seconds, more preferably 15 to 80 seconds, particularly preferably 15 to 50 seconds.

If it is provided to the solid state polyaddition treatment mentioned below, the mixture obtained by the melt-kneading described above preferably has a pellet shape. Using a twin screw-extruder for the melt-kneading, the mixture is extruded from the extruder into strands (diameter = preferably 1 to 10 mm, more preferably 3 to 5 mm) and then pelletized The pellets are cut and pelletized by me to obtain solid-chip-shaped pellets.

For reference, the fiber-reinforced polyester resin molding material obtained by the above-mentioned process comprising the melt-kneading step and the following solid phase polyaddition step mentioned below is one preferred embodiment of the present invention.

(Solid state polyaddition reaction):

The method for producing a fiber-reinforced polyester resin molding material according to the present invention comprises the steps of melt-kneading a mixture comprising a polyester resin and a polycarboxylic anhydride; Thereafter, characterized in that it comprises the step of performing a solid state polyaddition reaction of the melt-kneaded mixture.

This process can be achieved by (1) a ratio (λ / η) of extensional viscosity (λ) to shear viscosity (η) as measured by a capillary viscometer at 280 ° C. and shear rate of 100 s ⁻¹ in the range of 15 to 40, or (2 ) Easily provide the above-mentioned fiber-reinforced polyester resin molding material according to the present invention, characterized in that the elongation viscosity (λ) is 10 to 50 kPa · s as measured by a capillary viscometer at 280 ° C. and a shear rate of 100 s ⁻¹ . Can be. This can facilitate the molding process such as extrusion, blow molding, or foam molding, which has problems when using conventional fiber-reinforced polyester resin molding materials, and can also be used for injection molding more preferably than conventionally. Fiber-reinforced polyester resin molding materials are objects of the present invention.

In the solid phase polyaddition, the melt-kneaded mixture used for this reaction is preferably in the form of pellets. The use of pellet-shaped mixtures has the economic advantage of not requiring the large reaction spaces indicated in the prior art (disclosed in JP-A-509776 / 1996) for the solid phase addition treatment of molded articles. The mixture is heated to 180 to 230 ° C. in a solid phase polyaddition reactor under a flow of inert gas at atmospheric pressure or under reduced pressure to perform a solid phase polyaddition reaction. The inert gas stream or reduced pressure effectively removes volatile components or water from the mixture.

A method for producing a fiber-reinforced polyester resin molding material according to the present invention comprises the steps of melt-kneading a mixture comprising a polyester resin and a polycarboxylic anhydride; Thereafter, comprising the step of performing a solid state polyaddition reaction of the melt-kneaded mixture, and also overcomes the disadvantages of the prior art disclosed in JP-A-509776 / 1996 which subjects the molded article to a solid state polyaddition reaction. Can be. Specifically, when the molded article produced from the prior art has a smooth surface, the fibrous material may protrude from the surface due to the difference between the coefficient of thermal expansion of the fibrous material and the polyester resin. Therefore, in the molded article obtained from the molded article, the protruding fibrous material lowers the surface smoothness of the molded article and degrades its appearance. Therefore, the prior art has a problem in that the deterioration of the appearance lowers the yield of the molded article and thus reduces the productivity of the molded article. The present invention solves these problems.

In the present invention, the advantages obtained by performing the solid state polyaddition reaction in a pellet state are as follows. The process of carrying out the melt-kneading addition reaction of the mixture containing the polyester resin and the polycarboxylic anhydride can also be used, but since the reaction is carried out at a higher temperature than the melting point of the polyester resin, the reaction proceeds excessively. Three-dimensionalization has the potential to happen. As a result, vent-up occurs inside the extruder, or the die expansion effect during extrusion provides a molded article of non-uniform thickness resulting in fracture or local stretching. Also, for example, the intrinsic viscosity (IV) distribution of the high-molecularized PET resin may be nonuniform or the intrinsic viscosity (IV) of the high-molecularized PET resin may not be measurable. In contrast, solid phase polyaddition can cause high-molecularization of the polyester resin to have a sufficiently high intrinsic viscosity without causing the above-mentioned problems. Thus, a preferred high-molecularization method that can be used in the present invention is a solid phase polyaddition reaction. Moreover, since it has a very high molecular weight so that the intrinsic viscosity (IV) can be measured, the molding material of the present invention containing the resin obtained by the solid state polyaddition reaction has a preferred form as a molding material. As a result, this molding material hardly sags (the deflection phenomenon is a property greatly influenced by the flexibility of the molding material), and thus a molded article having good moldability and appearance can be provided. That is, it is a material which has the outstanding fluidity | liquidity according to these flexibility.

The solid state polyaddition reaction provides a high-molecular fiber-reinforced polyester resin molding material comprising a polyester resin with increased intrinsic viscosity, and preferably intrinsic viscosity of the fiber-reinforced polyester resin molding material is preferably 0.6 dl / g. As mentioned above, More preferably, it increases to 0.6-1.8 dl / g, Especially preferably, it increases to 0.7-1.5 dl / g.

For reference, when the fiber-reinforced polyester resin molding material according to the present invention is produced, the timing of adding the reinforcing fibers is not particularly limited. For example, the resin resulting from the solid phase polyaddition of the melt-kneaded mixture comprising the polyester resin and the polycarboxylic anhydride may be melt-kneaded again before adding the reinforcing fibers thereto. Preferably, however, if the mixture comprising the polyester resin and the polycarboxylic anhydride is melt-kneaded before the solid state polyaddition reaction, reinforcing fibers are added, and then the solid state polyaddition reaction is carried out in the presence of the reinforcing fibers. More preferably, the solid phase polyaddition reaction is carried out in the pelletized state in the presence of reinforcing fibers. The solid phase polyaddition reaction in the presence of the reinforcing fibers by this method has an advantage that the reinforcing fibers can be prevented from being damaged by kneading with the resin having increased molecular weight.

(Molding process):

The fiber-reinforced polyester resin molding material according to the invention is preferably used for one or more melt-molding processes selected from the group of molding processes consisting of injection molding, extrusion molding, blow molding and foam molding. In the fiber-reinforced polyester resin according to the present invention, if the ratio of elongational viscosity to shear viscosity is in a certain range, or if the elongational viscosity is in a certain range, the moldability of the molding material is excellent, in particular molding in extrusion or blow molding The resin is satisfactory without sagging, and a uniform, precise foamed product can be obtained by foam molding, and a molded article excellent in mechanical properties and appearance can be obtained by the molding process and injection molding.

In the fiber-reinforced polyester resin molding material according to the present invention, when polyolefin is added to them as described above, the melt-flow characteristics are characterized by high shear sensitivity even after melt-kneading or solid state polyaddition. Considering the high intrinsic viscosity, the fluidity in the forming step is better. For example, better moldability may be seen in injection molding than in the prior art.

The molding machine used is not particularly limited, but preferred examples thereof include a conventional injection molding machine or a so-called injection compression molding machine, and a twin screw-screw extruder, a single screw-screw extruder, a twin screw-screw extruder with an exhaust port, a single screw with an exhaust port- Screw extruder.

The molding process is preferably carried out in the molding temperature range of 260 to 300 ℃. Below 260 ° C. there is a problem of vent-up, for example in molding machines. When it exceeds 300 degreeC, there exists a problem in that resin may decompose | disassemble, for example, coloring or molecular weight reduction is caused. When a conventional fiber-reinforced polyester resin molding material is used for molding, it is disadvantageous in that a molded article having poor mechanical properties is simply obtained if, for example, the temperature is not strictly controlled in a small temperature range during extrusion. However, the fiber-reinforced polyester resin molding material according to the present invention can be molded in the above wide temperature range of 260 to 300 DEG C because of its very good moldability, and provides a molded article having excellent mechanical properties.

(Molded product):

The molded article according to the invention is obtained by a process comprising the step of molding the fiber-reinforced polyester resin molding material according to the invention. This molded article preferably has a tensile elongation of 1.5% or more and a surface crystallinity of 20% or more. If the tensile elongation is less than 1.5%, it is disadvantageous in that the fatigue property of the molded article is greatly deteriorated.

In addition, the molded article according to the present invention comprises a fiber-reinforced polyester resin molding material, the amorphous molded article and measured by analyzing the amorphous molded article produced by DSC at a heating rate of 10 ℃ / min, tensile elongation of 1.5% or more and It is preferable that cooling crystallization temperature is 115 degreeC or more. More preferably, the cooling crystallization temperature is in the range of 120 to 140 ° C. If the tensile elongation is less than 1.5%, it is disadvantageous in that flexibility is greatly deteriorated. In addition, when the cooling crystallization temperature is 115 ° C. and the molded article is obtained by rapid crystallization, there are many disadvantages in that, for example, the internal deformation and deflection are large.

In addition, considering that the molded article can provide value as an aesthetic product, it is preferable that the molded article according to the present invention has a surface glossiness of 50 or more. If the surface glossiness is less than 50, the molded article is disadvantageous in that it loses its commercial value as an aesthetic product such as an exterior plate.

For reference, the surface glossiness of the molded article can be evaluated, for example, by molding the molding material of the present invention into a mold having a metal surface at the chrome-plated finish.

(Applied to recycled PET):

When the composition and method is applied to recycled PET of polyester-molded products such as PET bottles, PET film final powder and various PET parts, it can enhance the impact resistance and mechanical strength of the fiber-reinforced PET obtained from recycled PET. It can provide a great added value to the fiber-reinforced PET. Thus, the configuration and method can be preferably used particularly for the reuse of the recycled PET, thus facilitating reuse.

By using the fiber-reinforced polyester resin molding material according to the present invention, it is possible to facilitate a molding process such as extrusion, blow molding or foam molding, which has problems in application to conventional fiber-reinforced polyester resin molding materials. It is also preferable for injection molding, and can provide a molded article having excellent mechanical properties, and can provide a method of molding a fiber-reinforced polyester resin molding material at a high cost performance ratio, and furthermore, to provide a molded article at a high cost performance ratio. Can provide. In addition, it is possible to easily provide the molding material according to the present invention through the manufacturing method of the fiber-reinforced polyester resin molding material according to the present invention.

The invention is explained in more detail below by comparing the following examples of some preferred embodiments with comparative examples which are not in accordance with the invention. However, the present invention is not limited to the following examples.

(Intrinsic viscosity (IV)):

1 g of resin was dissolved in 100 ml of a 60/40 (weight ratio) mixed solvent of phenol / tetrachloroethane and the intrinsic viscosity was measured at 25 ° C.

(Extension viscosity and shear viscosity):

Shear viscosity η is the viscosity coefficient of the fluid in the shear stress field, while elongation viscosity λ is the viscosity coefficient of the fluid in the stretch stress field. Elongational viscosities are measured by methods such as uniaxial or biaxial stretching, but some materials are difficult to measure their elongational viscosities or difficult to obtain reproducible extensional viscosity data. In this specification, the elongation viscosity is measured by a two-barrel type capillary viscometer (Rheometer RH-7 model of Rosand Co., Ltd.) by a method based on Cogswell's theory, which is a method of simply measuring the elongation viscosity with good reproducibility. Measured.

The measurement method was performed as follows: First, as shown in Fig. 1, a pressure sensor, a mold having a length of 16 mm, a diameter of 1 mm, and a mold penetration angle of 120 °, a mold having a length of 0.25 mm, a diameter of 1 mm, and a mold penetration angle of 120 ° Was inserted into two heatable barrels with an internal diameter of 18 mm. Then, the sample was filled in both barrels heated to the temperature more than melting | fusing point of a sample. After the sample reached the barrel temperature (the sample was held at that temperature for 6 minutes), pressure was applied at constant speed from the top with a piston to extrude the sample from the capillary. The pressure began to be applied at a constant rate and then waited until the internal pressure of the material became constant. After reaching the pressure equilibrium, the pressure values on the long-mold side and the short-mold side were recorded respectively. By varying the lowering speed of the piston, the pressure values at several speeds were measured in the same manner as above.

Shear velocity (γ), shear viscosity (η) and elongation viscosity (λ) were calculated according to the following equation, and the elongation viscosity at shear rate 100s ^-1 was determined by interpolation by plotting the shear viscosity versus elongation viscosity. .

In addition, all measurements were performed at 280 ° C without exception.

Shear rate

Shear stress

Apparent shear viscosity

Kidney stress

Elongation viscosity

Where r is the capillary radius,

L is the capillary length,

Q is the volumetric flow rate

PS is the pressure drop across the entire mold,

PL is the pressure drop across the intestinal mold,

n is the power law index.

(Cooling Crystallization Temperature):

The cooling crystal temperature of the sample obtained by randomly sampling about 10 mg from the resin composition or from the molded article was measured by a DSC measuring instrument (device name: DSC-50, manufactured by Shimadzu Corporation) under conditions of raising the temperature by 10 ° C per minute. If it was already crystallized, the sample was amorphous and then the cooling crystallization temperature was measured). The maximum cooling crystallization temperature was taken as the cooling crystallization temperature.

(Crystallinity):

The crystallinity of the sample obtained by randomly sampling the amount of about 10 mg from the molded article was measured by a DSC measuring instrument (device name: DSC 50, manufactured by Shimadzu Corporation) under conditions of increasing the temperature by 10 ° C per minute. The crystallinity was calculated from [(melting endothermic amount)-(cooling crystallization calorific value) / (crystal calorific value)] x 100.

Tensile Elongation

Tensile elongation was measured by an Instron universal material testing machine according to JIS-K-7113.

(Surface glossiness):

Surface glossiness was measured by the glossmeter (the apparatus name: VG-2000, Nippon Denshoku) according to the application section 5.2 of JIS-K-7105.

(Bending Strength):

Flexural strength was measured with an Instron universal material testing machine according to JIS-K-7203.

(Examples 1-7)

Polyethylene terephthalate (PET; IV = 0.60 dl / g), pyromellitic dianhydride (hereinafter abbreviated as PMDA), chopped glass fibers (length 3mm, diameter 10㎛, GF for short) and talc ( As a nucleating agent) is melt-kneaded with a counterrotating non-engaged twin screw-screw extruder at a mixing ratio of Table 1 at 300 ° C. for an average residence time of 15 to 30 seconds, and the resulting melt-kneaded mixture stranded from the mold of the extruder. Extruded into shape. The extruded strands were cooled in water and pelletized with a strand cutter to obtain individual pellets with an IV of 0.53 dl / g.

In order to increase the intrinsic viscosity of the obtained pellets, the solid state polyaddition reaction of the pellets was carried out at 200 ° C. for each time of Table 2 to obtain pellets of the glass-fiber-reinforced polyester resin composition. The pellets thus obtained were dried under vacuum at 160 ° C. for 6 hours, introduced into an extruder, and subjected to extrusion at each molding temperature shown in Table 2 to obtain a molded article in the form of a flat plate. Table 2 also shows the following properties of the resin composition: cooling crystallization temperature, ratio of elongational viscosity (λ) to shear viscosity (η) during extrusion (λ / η), elongation viscosity (λ) during extrusion, and Whether the resin sag during molding. As shown in Table 2, treatment of the solid state polyaddition reaction in the pelletized state increased the IV of the pellet from 0.53 dl / g to 0.7-1.4 dl / g.

PET weight% PMDA weight% GF weight% Talc weight% Example 1 55 0.25 45 0.7 Example 2 70 0.25 30 0.7 Example 3 85 0.25 15 0.7 Example 4 90 0.25 10 0.7 Example 5 70 0.25 30 0.7 Example 6 70 0.25 30 0.7 Example 7 70 0.25 30 0.7 Example 8 70 0.25 30 0.7 Example 9 70 0.25 30 0.7 Comparative Example 1 55 0 45 0.7 Comparative Example 2 70 0 30 0.7 Comparative Example 3 85 0 15 0.7 Comparative Example 4 90 0.25 10 0.7 Comparative Example 5 70 0 30 0.7 Comparative Example 6 70 0 30 0.7 Comparative Example 7 70 0 30 0.7 Comparative Example 8 70 0 30 0.7

In order to measure the mechanical-characteristics of the molded article obtained above, the specimens were cut into specimens, their tensile elongation and surface glossiness were measured, and the results are shown in Table 3. In addition, the surface appearance of the molded article is excellent (◎), good ( ), usually( ) And defects are indicated, and Table 3 shows whether the molded product is deflected.

Tensile Elongation (%) Surface appearance Deflection of Molded Parts Surface glossiness Portrait orientation Landscape orientation Example 1 1.8 1.8 ◎ none 62 Example 2 1.9 1.8 ◎ none 65 Example 3 2.2 1.9 ◎ none 61 Example 4 2.4 1.9 ◎ none 59 Example 5 2.5 2.3 ◎ none 62 Example 6 1.6 1.5 ◎ none 63 Example 7 2.8 2.2 Almost none 58 Example 8 1.5 1.5 Almost none 57 Comparative Example 1 1.2 0.7 Ⅹ Occur 42 Comparative Example 2 - - Not molded - 38 Comparative Example 3 - - Not molded - 35 Comparative Example 4 - - Not molded - 35 Comparative Example 5 1.2 0.8 Occur 64 Comparative Example 6 1.2 0.8 Occur 50

Example 8

PET, PMDA, GF and talc (as nucleating agent) were melt-kneaded in a co-rotating twin-screw extruder at a mixing ratio of Table 1 at 300 ° C., and the resulting melt-kneaded mixture was stranded from the mold of the extruder. Extruded. The extruded strands were cooled in water and pelletized with a strand cutter to obtain pellets.

The obtained pellets were dried under vacuum for 6 hours at 160 ° C., and then subjected to an extrusion molding machine without performing a solid state polyaddition reaction, and extruded at a molding temperature shown in Table 2 to obtain a plate-shaped molded product.

Similar to Examples 1-7, the mixing ratios are shown in Table 1. Conditions and results are shown in Tables 2 and 3.

Example 9

After the solid state polyaddition reaction, the hollow ratio 3 (= (thickness of extruded melt-kneaded resin / thickness of molded article)) was obtained in the same manner as in Example 2, except that the pellets were introduced into the blow molding machine and then blow-molded. The bottle-shaped molded article was obtained, the mixing ratio is shown in Table 1, the conditions and the results are shown in Table 2. In addition, the occurrence of tearing in the hollow step is shown in Table 2. The hollow having excellent appearance Molded parts were obtained without tearing in the hollow stage.

(Comparative Examples 1-4)

Molded articles were obtained in the same manner as in Examples 1-4 except for the following: Melt-kneading was carried out at the mixing ratios in Table 1 without adding PMDA; No solid phase polyaddition was performed; The extrusion state was as shown in Table 2. The mechanical properties of the obtained molded article are shown in Table 3.

(Comparative Example 5)

Melt-kneading was carried out at the same mixing ratio as in Example 5 (Table 1), except that PMDA was not added at 300 ° C using a reverse-rotating non-engaging twin screw extruder. The resulting melt-kneading mixture was extruded in strand form from the molds of the extruder. The extruded strands were cooled in water and pelletized with a strand cutter to obtain pellets.

The obtained pellets were dried at 160 ° C. under vacuum for 6 hours, and then introduced into an extrusion molding machine without performing a solid state polyaddition reaction to perform extrusion molding at a molding temperature shown in Table 2 to obtain a plate-shaped molded product. Table 2 also shows the following properties of the resin composition: cooling crystallization temperature, ratio of elongational viscosity (λ) to shear viscosity (η) during extrusion (λ / η), elongation viscosity (λ) during extrusion, and Whether the resin sag during molding.

After carrying out the solid state polyaddition reaction of the molded article obtained above at 6O < 0 > C for 6 hours, the specimen was cut into test pieces for measuring the mechanical properties of the molded article, and then the tensile elongation and surface glossiness were measured. 3 is shown. In addition, the surface appearance of the molded article is excellent (◎), good ( ), usually( ) And defects are indicated, and Table 3 shows whether the molded product is deflected.

(Comparative Example 6)

Melt-kneading was carried out in a mixing ratio of Table 1 without adding PMDA at 300 ° C. with a counter-rotating non-engrave bi-screw extruder. The resulting melt-kneading mixture was extruded in strand form from the molds of the extruder. The extruded strands were cooled in water, pelleted with a strand cutter, and the pellets were obtained.

Solid phase polyaddition was carried out at 200 ° C. for 23 hours to increase the intrinsic viscosity of the pellets to obtain pellets of the fiber-reinforced polyester resin combination. The obtained pellets were dried under vacuum at 160 ° C. for 6 hours, then introduced into an extrusion machine, and subjected to extrusion at a molding temperature of Table 2 to obtain a molded article in a flat form. The results are shown in Tables 2 and 3.

(Comparative Example 7)

The molded article was obtained in the same manner as in Example 9 except for the following: Melt-kneading was carried out at the mixing ratios of Table 1 without adding PMDA; No solid phase polyaddition was performed; Blow molding conditions were set as shown in Table 2. As a result, tearing occurred in the hollow stage and a hollow-molded article could not be obtained.

(Comparative Example 8)

The pellets obtained by melt-kneading were introduced into the blow molding machine under the conditions of Table 2, and then blow-molded in the same manner as in Example 6, with the ratio of hollow ratio 3 (= (thickness of extruded melt-kneading resin / The thickness of the molded article) was obtained, and the results are shown in Table 2. Tearing occurred and a molded article could not be obtained.

(Comparative Examples 10-16)

PET or recycled PET (IV = 0.60 dl / g), PMDA, GF and talc (as nucleating agent), and if necessary, polyolefins were mixed at 300 in a mixing ratio of Table 4 using a reverse-rotating non-interlocking twin screw extruder. Melt-kneading at an average residence time of 15 seconds to 30 seconds at < RTI ID = 0.0 > C < / RTI > and the resulting mixture was extruded into strands from the mold of the extruder. The extruded strands were cooled in water, pelleted with a strand cutter, and each strand was obtained.

In order to increase the intrinsic viscosity of the obtained pellets, the solid state polyaddition reaction of the pellets was carried out at 200 ° C. for each time of Table 5 to obtain a glass-fiber-reinforced polyester resin composition. The obtained pellets were dried in a vacuum at 160 ° C. for 6 hours, and then introduced into an injection molding machine (SG-25-HIPRO MII, Sumitomo Heavy Machine Industries, Ltd.) for injection at each molding temperature shown in Table 5. Each molded article was obtained by performing molding. In addition, Table 5 shows the following properties of the above resin composition: cooling crystallization temperature, ratio of elongation viscosity (λ) to shear viscosity (η) during injection (λ / η), and elongation viscosity (λ) during injection.

PET weight% PMDA weight% GF weight% Talc weight% Polyolefin Weight% Example 10 70 0.25 30 0.7 none Example 11 70 0.25 30 0.7 none Example 12 70 0.25 30 0.7 none Example 13 70 ^{* 1)} 0.25 30 0.7 none Example 14 70 ^{* 1)} 0.25 30 0.7 none Example 15 70 0.25 30 0.7 0.70 ^{* 2)} Example 16 70 0.25 30 0.7 0.70 ^{* 3)} Comparative Example 9 70 0.25 30 0.7 none Comparative Example 10 70 0.25 30 0.7 none Comparative Example 11 70 0.25 30 0.7 0.70 ^{* 2} Comparative Example 12 70 0.25 30 0.7 none

1) recycled PET

2) polypropylene copolymer (weight-average molecular weight = 52,900)

3) polypropylene (weight-average molecular weight = 50,600)

After cutting into a test piece for measuring the mechanical properties of the molded article obtained as described above, the tensile strength, tensile elongation rate, flexural strength and surface appearance (◎: excellent, ○: good, △: normal, ×: poor) was measured and The results are shown in Table 6.

Solid state addition time (hours) Intrinsic viscosity (dl / g) Tensile Elongation (%) Flexural strength (MPa) Surface appearance Longitudinal direction Width direction Example 10 4 0.65 2.0 1.6 235 ◎ Example 11 6 0.73 2.8 2.2 237 ◎ Example 12 8 0.83 2.5 2.0 238 ◎ Example 13 6 0.74 2.0 1.7 232 ◎ Example 14 8 0.85 2.2 1.9 238 ◎ Example 15 8 0.82 2.3 1.9 226 ◎ Example 16 8 0.80 2.1 1.8 223 ◎ Comparative Example 9 6 ^{* 1} 0.71 ^{* 2} 1.0 0.6 221 Ⅹ Comparative Example 10 8 ^{* 1} 0.82 ^{* 2} 1.1 0.7 219 Ⅹ Comparative Example 11 8 ^{* 1} 0.81 ^{* 2} 1.1 0.7 223 Ⅹ Comparative Example 12 - 0.47 1.3 0.9 211

1) Solid state polyaddition reaction treatment time of injection-molded test pieces.

2) Intrinsic viscosity after solid state polyaddition reaction of injection-molded test piece

(Comparative Examples 9 ~ 11)

PET (IV = 0.60 dl / g), PMDA, GF and talc (as nucleating agent) and if necessary polyolefin were melt-kneaded at the mixing ratios in Table 4 under the same conditions as in Example 10 to obtain pellets.

The obtained pellets were injection-molded under the conditions of Table 5 without undergoing a solid state polyaddition reaction. As a result, a molded article was obtained. Table 5 also shows the following properties of the resin composition: cooling crystallization temperature, ratio of elongational viscosity (λ) to shear viscosity (η) during injection (λ / η) and elongation viscosity (λ) during injection; And injection molding conditions.

Then, the pieces for mechanical-characteristic measurement were prepared in the same manner as in Example 10, and then subjected to a solid state polyaddition reaction at 200 ° C. for each time of Table 6. Tensile strength, tensile elongation rate, flexural strength and surface appearance of the obtained quality-enhancing test pieces were measured (◎: excellent, ○: good, Δ: normal, ×: poor), and the results are shown in Table 6.

(Comparative Example 12)

Pellets were obtained by melt-kneading at the mixing ratio of Table 4 under the same conditions as in Example 10 without using PMDA.

The obtained pellets were injection-molded under the conditions of Table 5 without undergoing a solid state polyaddition reaction. As a result, a molded article was obtained. Table 5 also shows the following properties of the resin composition: cooling crystallization temperature, ratio of elongational viscosity (λ) to shear viscosity (η) during injection (λ / η), elongation viscosity (λ) during injection; And injection molding conditions.

Next, test pieces for measuring mechanical properties were prepared in the same manner as in Example 10, and then measured for tensile strength, tensile elongation, bending strength and surface appearance (◎: excellent, ○: good, △: normal, × : Bad), and the results are shown in Table 6.

Various details of the invention may be changed without departing from the spirit and scope of the invention. In addition, the foregoing description of the preferred embodiments according to the present invention is provided for illustrative purposes only, and not for the purpose of limiting the invention to the appended claims and the like.

Claims (11)

Fiber-reinforced polyester resin molding characterized in that the ratio of elongational viscosity (λ) to shear viscosity (η) (λ / η) as measured by capillary viscometer at 280 ° C., shear rate 100s ⁻¹ ranges from 15 to 40 material. A fiber-reinforced polyester resin molding material having an elongational viscosity (λ) of 10 to 50 kPa · s as measured by a capillary viscometer at 280 ° C. and a shear rate of 100 s ⁻¹ . 3. The fiber-reinforced polyester resin molding material according to claim 1 or 2, comprising a resin obtained by a process comprising melt-kneading a mixture of a polyester resin and a polycarboxylic anhydride. The method of claim 1 or 2, further comprising: melt-kneading the mixture comprising the polyester resin and the polycarboxylic anhydride; A fiber-reinforced polyester resin molding material comprising a resin obtained by a process comprising then performing a solid state polyaddition reaction of the melt-kneaded mixture. The fiber-reinforced polyester resin molding according to claim 3 or 4, wherein the mixture comprising the polyester resin and the polycarboxylic anhydride further comprises a polyolefin. 6. The fiber-reinforced polyester resin molding according to claim 5, wherein the mixture comprises polyolefin in a ratio of 0.05 to 10 parts by weight per 100 parts by weight of the polyester resin. The fiber-reinforced polyester resin molding according to any one of claims 1 to 6, having an intrinsic viscosity (IV) of 0.6 to 1.8 (dl / g) before being used for molding. 8. The fiber-reinforced polyester molding material according to any one of claims 1 to 7, which is used for at least one melt-molding process selected from the group of molding processes consisting of injection molding, extrusion molding, blow molding and foam molding. . Melt-kneading the mixture comprising the polyester resin and the polycarboxylic anhydride; And then performing a solid state polyaddition reaction of the melt-kneaded mixture. The production process according to claim 9, wherein the solid state polyaddition reaction is carried out in a pellet state. A molded article obtained by a process comprising the step of molding the fiber-reinforced polyester molding material according to claim 1.