TW201422660A - Wholly aromatic polyester, polyester resin composition, and a polyester molded article - Google Patents

Abstract

A wholly aromatic polyester having excellent heat resistance and toughness, and showing optical anisotropy when molten, and a composition thereof are provided. This wholly aromatic polyester showing optical anisotropy when molten is characterized by containing, as essential constituent components, the constituent units represented by general formulae (I), (II), (III), (IV) and (V), and in that, in relation to the total constituent units, constituent units (I) are 35-75 mol%, constituent units (II) are 2-8 mol%, constituent units (III) are 8.5-31.5 mol%, constituent units (IV) are 2-8 mol%, constituent units (V) are 0.5-29.5 mol%, and constituent units (II)+(IV) are 4-10 mol%. This polyester resin composition is formed by mixing 120 parts by mass or less of an inorganic or organic filler per 100 parts by mass of said wholly aromatic polyester.

Description

Fully aromatic polyester and polyester resin composition and polyester molded article

The present invention relates to a wholly aromatic polyester and polyester resin composition which has good heat resistance and toughness and can be produced by a usual polymerization apparatus, and a polyester molded article which is formed by molding these.

It is now sold in the market as a component of the all-aromatic polyester 4-hydroxybenzoic acid. However, since the homopolymer of 4-hydroxybenzoic acid has a melting point higher than the decomposition point, it is necessary to lower the melting point by copolymerizing various components.

A wholly aromatic polyester having a copolymerization component using terephthalic acid, hydroquinone, 4,4'-dihydroxybiphenyl or the like has a melting point of up to 350 ° C or higher, in order to be melted by a general-purpose apparatus Processing, therefore, the melting point is too high. Further, in order to reduce such a high melting point to a temperature at which processing can be performed by a general-purpose melt processing machine, various methods are tried, but a certain degree of low melting point is achieved, and on the other hand, there is a so-called failure. The problem of heat resistance represented by the mechanical strength maintained at a high temperature (near the melting point) occurs.

In order to solve these problems, in Patent Documents 1 to 3, a copolymerized polyester of 6-hydroxy-2-naphthoic acid, a glycol component, and a dicarboxylic acid component is proposed to be combined with 4-hydroxybenzoic acid.

However, the copolymerized polyesters proposed in Patent Documents 1 to 3 have The toughness is lowered, and cracking or toughness is caused in the molded article at the time of molding, but the heat resistance is insufficient.

On the other hand, the above-mentioned wholly aromatic polyester exhibits optical anisotropy when it is melted, and is called a liquid crystalline polymer, and has good dimensional accuracy, vibration damping property, and fluidity, and burrs occur during molding. It is useful as a material for various electronic parts. In the planar electronic connector having a lattice structure inside the frame represented by the CPU socket, the tendency to increase the heat resistance, increase the density, and downsize is remarkable. Most of the liquid crystals are reinforced by glass fibers. Polymer composition. However, even in the glass fiber-reinforced liquid crystalline polymer composition having a certain degree of fluidity, the width of the resin portion which is a gap between the lattice portions which are required to be required in recent years and which is 2 mm or less and which holds the lattice portion of the terminal is used. The performance is insufficient for a very thin-walled planar electronic connector of 0.5 mm or less. In other words, in the planar electronic connector in which the width of the lattice portion is extremely thin, when the resin is filled to the lattice portion, the fluidity is insufficient, so that the filling pressure is increased, and as a result, it is obtained. The problem of a large amount of bending deformation of the planar electronic connector occurs. In order to solve this problem, it is conceivable to use a liquid crystalline polymer composition having a low fluidity to reduce the amount of glass fiber added. However, in such a composition, the strength is insufficient, and deformation occurs due to remelting at the time of constitution. The problem.

Then, the present inventors propose a planar electronic connector composed of a specific composite resin composition in which the weight average length and the amount of the kinetic filler are in a certain relationship (refer to Patent Document 4). . According to the invention described in Patent Document 4, even a thin-walled planar electronic connector can be obtained in formability, flatness, bending deformation, heat resistance, and the like. The performance is good.

However, it is known that the shape change due to the increase in the accumulation rate of the planar electronic connector, in particular, the increase in the number of pins of the electronic connector, and the thinning of the width of the lattice portion, etc. However, it does not correspond to the state of the invention described in the above Patent Document 4.

Therefore, the inventors have also proposed to use for a specific liquid crystalline polymer ^. A planar electronic connector formed by laminating a specific composite resin composition of a plate-like filler and a fibrous filler (refer to Patent Document 5). According to the invention of Patent Document 5, even in the case of a thin-walled planar electronic connector, the performance in terms of formability, flatness, bending deformation, heat resistance, and the like is improved, and It is also possible to obtain a change in shape even with an increase in the accumulation rate of the planar electronic connector, in particular, an increase in the number of pins of the electronic connector, and a further increase in the width of the lattice portion. Corresponding.

However, in the invention described in Patent Document 5, cracks (cracks) after molding occur in the lattice portion due to variations in manufacturing conditions such as manufacturing variations of the polymer and molding conditions, and the crack resistance is not sufficiently obtained. Performance.

On the other hand, the aforementioned problems are not only planar electronic connectors, but also various electronic connectors, CPU sockets, relay switch parts, bobbins, actuators, noise reduction filter boxes, or OA machines. A variety of molded articles such as fixed press rolls are heated.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Laid-Open Patent Publication No. 59-43021

Patent Document 2: Japanese Laid-Open Patent Publication No. 59-62630

Patent Document 3: Japanese Patent Laid-Open No. Hei 11-506145

Patent Document 4: Japanese Laid-Open Patent Publication No. 2005-276758

Patent Document 5: JP-A-2010-3661

The present invention has an object to provide a wholly aromatic polyester and a composition thereof which have the above-mentioned problems and which have good heat resistance and toughness and exhibit optical anisotropy upon melting.

Further, the present invention has an object of providing a polyester molded article which is excellent in moldability and has excellent heat resistance and crack resistance, and the like, in particular, in a state of being formed into a shape of a plate or a film. A polyester molded article which has the above-mentioned good properties and which has less bending deformation and also has a good flatness.

The inventors of the present invention have conducted research intensively, and as a result, found that by 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, terephthalic acid, resorcinol, 4, a polymer composed of a 4'-dihydroxybiphenyl group, which is combined with a 6-hydroxy-2-naphthoic acid and a resorcinol in a particularly limited amount to effectively achieve the foregoing purpose, so as to complete the present invention. .

(1) A wholly aromatic polyester which exhibits optical anisotropy upon melting, and is characterized in that the essential structural components include the following general formulae (I), (II), (III), (IV) And the structural unit represented by (V), the structural unit of (I) relative to the total structural unit is 35 to 75 mol%, (II) The structural unit is 2~8 mol%, the structural unit of (III) is 8.5~31.5 mol%, the structural unit of (IV) is 2~8 mol%, and the structural unit of (V) is 0.5~29.5 mo The structural unit of %, (II) + (IV) is 4 to 10% by mole.

(2) The wholly aromatic polyester according to the above (1), wherein the melt viscosity at a shear rate of 1000 sec ^-1 is 1 × 10 ⁵ Pa at a temperature higher than a melting point of the wholly aromatic polyester of 10 to 40 °C. . s below.

(3) The wholly aromatic polyester according to the above (1) or (2), wherein the melting point is 280 to 390 °C.

(4) A polyester resin composition obtained by blending 120 parts by mass or less of an inorganic or organic filler with 100 parts by mass of the wholly aromatic polyester according to any one of the above (1) to (3). composition.

(5) The polyester resin composition according to (4) above, wherein The inorganic filler is one or more selected from the group consisting of glass fiber, mica and talc, and the amount thereof is 20 to 80 parts by mass based on 100 parts by mass of the wholly aromatic polyester.

(6) A polyester molded article obtained by molding the wholly aromatic polyester according to any one of (1) to (3) above or the polyester resin composition according to (4) or (5) above.

(7) The polyester molded article according to the above (6), wherein the molded article is an electronic connector, a CPU socket, a relay switch component, a bobbin, an actuator, a noise reduction filter case, or a heating of an OA machine. Fixed pressure roller.

(8) The polyester molded article according to the above aspect, wherein the molded article has a lattice structure inside the outer frame, and the lattice portion has a structure with a space of 1.5 mm or less.

(9) The polyester molded article according to the above (6), wherein the molded article is a polyester fiber.

(10) The polyester molded article according to the above (6), wherein the molded article is a polyester film.

According to the present invention, it is possible to provide a wholly aromatic polyester having a good heat resistance and toughness and exhibiting optical anisotropy upon melting and a composition thereof.

Further, according to the present invention, it is possible to provide a polyester molded article which is excellent in moldability and has excellent heat resistance and crack resistance, and the like, particularly in a shape formed into a shape of a plate or a film. a polyester which has a good flatness and which has a good flatness in addition to the aforementioned good properties. Molded product.

That is, the wholly aromatic polyester and its composition which are composed by the specific structural unit obtained by the present invention and exhibit an anisotropy upon melting, are fluidity at the time of melting and heat resistance of the molded article. It has good properties, good toughness, and low forming temperature. Therefore, it can be injection molded, extruded, and compression molded without using a molding machine having a special structure. Three-dimensional molded articles, fibers, films, and the like. In particular, it is suitable for molded products such as electronic connectors, CPU sockets, relay switch parts, bobbins, actuators, noise reduction filter box boxes, or heating fixed pressure rolls of OA machines. Further, a planar electronic connector having good moldability, small bending deformation, and good flatness, heat resistance, and crack resistance can be obtained by various properties described above.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a planar electronic connector formed by an embodiment. Fig. 1(a) is a plan view, and Fig. 1(b) is a detailed view of a portion A. Further, the numerical unit in the figure is mm.

Fig. 2 is a view showing a molded article used for evaluation of crack resistance of a molded article in the embodiment, Fig. 2(a) is a plan view thereof, and Fig. 2(b) is a view showing a size thereof, and in addition, the numerical value in the figure The unit is mm.

<Full aromatic polyester>

The wholly aromatic polyester of the present invention is a wholly aromatic polyester which exhibits optical anisotropy upon melting, and is characterized in that it contains the following structural constituents as necessary The structural units represented by the general formulae (I), (II), (III), (IV), and (V) are 35 to 75 mol% of the structural unit of (I) with respect to the total structural unit, ( The structural unit of II) is 2~8 mol%, the structural unit of (III) is 8.5~31.5 mol%, the structural unit of (IV) is 2~8 mol%, and the structural unit of (V) is 0.5~ 29.5 Mohr%, (II) + (IV) has a structural unit of 4 to 10 mol%.

In order to specifically realize the structural units of the above-described general formulae (I) to (V), various compounds having a usual ester forming ability are used. Hereinafter, in order to form the wholly aromatic polyester constituting the present invention, the necessary raw material compounds will be described in detail in order.

The structural unit (I) is introduced from 4-hydroxybenzoic acid.

The structural unit (II) was introduced from 6-hydroxy-2-naphthoic acid.

The structural unit (III) is introduced from terephthalic acid.

The structural unit (IV) is introduced from resorcinol.

Further, the structural unit (V) is introduced from a 4,4'-dihydroxybiphenyl group.

In the present invention, it is necessary to include the aforementioned structural units (I) to (V), the position is relative to the total structural unit and the structural unit of (I) is 35 to 75 mol% (preferably 40 to 65 mol%). ), the structural unit of (II) is 2~8 mole% (preferably 3~7 mole%), and the structural unit of (III) is 8.5~31.5 mole% (preferably 14~29 mole%) ), the structural unit of (IV) is 2~8 mole% (preferably 3~7 mole%), and the structural unit of (V) is 0.5~29.5 mole% (preferably 10~22 mole%) The structural unit of (II) + (IV) is in the range of 4 to 10 mol% (preferably 6 to 10 mol%).

When the structural unit of (I) is less than 35 mol% and more than 75 mol%, the melting point is remarkably high, and the polymer is solidified in the reactor at the time of manufacture, which is impossible to manufacture. The polymer of the desired molecular weight, therefore, becomes undesirable.

When the structural unit of (II) is less than 2 mol%, the toughness becomes low and it becomes unsatisfactory. Further, at a temperature more than 8 mol%, the heat resistance of the polymer is lowered, and therefore, it is not preferable.

When the structural unit of (III) is less than 8.5 mol% and more than 31.5 mol%, the melting point is remarkably high, and the polymer is solidified in the reactor at the time of manufacture, which is impossible to manufacture. The polymer of the desired molecular weight, therefore, becomes undesirable.

When the structural unit of (IV) is less than 2 mol%, the toughness becomes low and it becomes unpreferable. In addition, when more than 8 mole%, the heat resistance of the polymer is lowered, Therefore, it becomes unsatisfactory.

Further, when the structural unit of (V) is less than 0.5 mol% and more than 29.5 mol%, the melting point is remarkably high, and the polymer is solidified in the reactor at the time of manufacture as the state is produced. It is impossible to produce a polymer having a desired molecular weight, and therefore, it becomes unsatisfactory.

Further, the structural unit of (II) + (IV) is less than 4 mol%, and the heat of crystallization of the polymer obtained by measuring the differential calorimetry of the crystallization state of the polymer is 2.0 J/g or more. The toughness is low and it is not ideal. The ideal value of the crystallization heat is 1.8 J/g or less, and more preferably 1.6 J/g or less. Further, when it is more than 10 mol%, the heat resistance of the polymer is lowered, and therefore, it becomes unsatisfactory.

In addition, the term "crystallization heat" refers to the observation of the endothermic peak temperature (Tm1) observed when the polymer is measured at a temperature rise of 20 ° C /min from the room temperature, and is measured at Tm1+. After holding at a temperature of 40 ° C for 2 minutes, the peak heat of the heat generation was determined by the peak of the observed peak temperature of the heat when measured at a temperature drop of 20 ° C /min.

Further, in the wholly aromatic polyester of the present invention, a small amount of other structural units other than the above-mentioned (I) to (V) may be introduced in a range which does not inhibit the effects of the present invention.

Japanese Patent Publication No. 59-43021 (Patent Document 1), JP-A-59-62630 (Patent Document 2), and JP-A-H11-506145 (Patent Document 3), It is proposed to combine 6-hydroxy-2-naphthoic acid, a glycol component, and a liquid crystal polymer of a dicarboxylic acid component in 4-hydroxybenzoic acid, for example, in Japanese Laid-Open Patent Publication No. 59-62630 (Special Example 22 of the document 2) proposes to consist of 57 mol% of the structural unit (I), 3 mol% of (II), 20 mol% of (III) and 20 mol% of (V). The liquid crystal polymer, however, has a problem that the liquid crystal polymer has a low toughness. Further, in Example 14 of Japanese Laid-Open Patent Publication No. Hei 11-506145 (Patent Document 3), it is proposed that 20% of the structural unit (I), 30% of (II), and 25% of (III) A liquid crystal polymer composed of %, (5), 5% by mole, and 20% by mole of (V). However, this liquid crystal polymer has a problem that the toughness is high but the heat resistance is insufficient.

On the other hand, in the present invention, the amount of the structural units (I) to (V) and the amount of the structural unit (II) + (IV) can be limited to the above range, and heat resistance and workability can be obtained. Any of the manufacturability and toughness is also a good all-aromatic polyester.

The wholly aromatic polyester of the present invention is polymerized by a direct polymerization method or a transesterification method, and a melt polymerization method, a solution polymerization method, a paste polymerization method, a solid phase polymerization method, or the like is used in the polymerization.

In the present invention, at the time of polymerization, a deuterating agent for a polymerizable monomer or a monomer using an activated terminal may be used as the acid chloride derivative. As the deuterating agent series, an acid anhydride such as acetic anhydride or the like is used.

At the time of these polymerizations, various catalysts can be used, and the representative series is a dialkyltin oxide, a diaryltin oxide, a titanium oxide, an alkoxytitanium salt, a titanium alkoxide, or a carboxylic acid. Alkali and alkaline earth metal salts, for example, Lewis acid salts of BF ₃ and the like. The amount of the catalyst used is generally from about 0.001 to 1% by mass, particularly preferably from about 0.003 to 0.2% by mass, based on the total weight of the monomers.

In addition, in the state of solution polymerization or paste polymerization, A liquid paraffin, a highly heat-resistant synthetic oil, an inert mineral oil, or the like is used for the solvent system.

The reaction conditions are a reaction temperature of 200 to 380 ° C and a final pressure of 0.1 to 760 Torr (that is, 13 to 101,080 Pa). Especially in the melting reaction, the reaction temperature is 260 ~ 380 ° C, preferably 300 ~ 360 ° C, and finally reaches the pressure system 1 ~ 100 Torr (that is, 133 ~ 13,300 Pa), preferably 1 ~ 50 Torr (that is, 133 ~ 6, 670 Pa).

The reaction system may also be carried out by charging the whole raw material monomer, the oximation agent and the catalyst into the same reaction vessel to start the reaction (one mode), and may also be used to deuterate the raw material monomer by the oximation agent (I). After the hydroxyl groups of (II), (IV) and (V), react with the carboxyl group of (III) (two-stage mode).

The melt polymerization is carried out after reaching a predetermined temperature in the reaction system, and then starting the pressure reduction to a predetermined degree of pressure reduction. After the torque of the agitator reaches a predetermined value, the inert gas is introduced and the pressure is reduced. The normal pressure is applied to the predetermined pressurized state, and the polymer is discharged from the reaction system.

The polymer system produced by the above polymerization method can also achieve an increase in molecular weight by solid phase polymerization by heating under normal pressure or reduced pressure in an inert gas. The ideal conditions for solid phase polymerization are reaction temperatures of 230 to 350 ° C, preferably 260 to 330 ° C, and finally a pressure of 10 to 760 Torr (ie 1,330 to 101,080 Pa).

The liquid crystalline polymer which exhibits optical anisotropy at the time of melting is an indispensable element in terms of both heat stability and workability in the present invention. The wholly aromatic polyester composed of the above structural units (I) to (V) also has no anisotropic melting phase due to the structural composition and the sequential distribution in the polymer, but the polymerization of the present invention The system is defined to come when melting A wholly aromatic polyester showing optical anisotropy.

The nature of the melting anisotropy can be confirmed by a conventional polarized light inspection method using orthogonal photons. More specifically, the confirmation of the melting anisotropy can be carried out by using a polarizing microscope manufactured by Olympus Co., Ltd., and melting the sample placed on a heating pedestal manufactured by Linkam Co., Ltd., and observing it at a magnification of 150 times in a nitrogen atmosphere. And implementation confirmation. The above-mentioned polymer is optically anisotropic and transmits light when inserted between orthogonal photoconductors. When the sample is optically anisotropic, for example, even in the molten stationary state, the polarized light is transmitted.

The wholly aromatic polyester of the present invention is considered to be liquid crystallinity and melting point (liquid crystallinity found temperature) as an index of workability. Whether or not the liquid crystallinity is closely related to the fluidity at the time of melting is exhibited, and the wholly aromatic polyester of the present invention is indispensable in exhibiting liquid crystallinity in a molten state.

Since the nematic liquid crystal polymer has a viscosity which is remarkably lowered at a melting point or higher, the liquid crystallinity generally exhibits a workability index at a temperature equal to or higher than the melting point. From the viewpoint of heat resistance, the melting point (liquid crystallinity found temperature) is preferably as high as possible, but when heat deterioration at the time of melt processing of the polymer or heating ability of the molding machine is considered, The 280~390°C system is the ideal standard. Further, it is more desirable to be 380 ° C or less.

Further, at a temperature higher than the melting point of 10 to 40 ° C, the melt viscosity of the shear rate of 1000 sec ^-1 is preferably 1 × 10 ⁵ Pa. s below. More ideal is 5Pa. s above, 1 × 10 ² Pa. s below. These melt viscosities are roughly realized by having liquid crystallinity.

<Polyester Resin Composition>

The polyester resin composition of the present invention is characterized in that it is composed of 120 parts by mass or less of an inorganic or organic filler in an amount of 100 parts by mass of the wholly aromatic polyester of the present invention.

The inorganic and organic fillers are in the form of fibers, powders, and plates.

As a fibrous filler series, glass fiber, asbestos fiber, cerium oxide fiber, cerium oxide ^. Alumina fiber, alumina fiber, zirconia fiber, oxygen nitride fiber, tantalum nitride fiber, boron fiber, potassium titanate fiber, silicate fiber such as ash stone, magnesium sulfate fiber, aluminum borate fiber, or even stainless steel An inorganic fibrous material such as a metal fiber such as aluminum, titanium, copper or brass. A particularly representative fibrous filler is a glass fiber. Further, a high melting point organic fibrous material such as polyamide, fluororesin, polyester resin or acryl resin may also be used.

On the other hand, as a series of powdery fillers, carbon black, graphite, cerium oxide, quartz powder, glass granules, rolled glass fiber, glass spheres, glass powder, calcium silicate, aluminum silicate, kaolin, clay, Algae earth, for example, strontium silicate, iron oxide, titanium oxide, zinc oxide, antimony trioxide, metal oxides such as alumina, metal carbonates such as calcium carbonate, magnesium carbonate, such as calcium sulfate, sulfuric acid Bismuth metal sulfate, other ferrite, tantalum carbide, tantalum nitride, nitrogen nitride, various metal powders, and the like.

Further, as the plate-shaped filler series, mica, glass flakes, talc, various metal foils, and the like are mentioned.

When an example of the organic filler is used, it is a heat-resistant high-strength synthetic fiber such as an aromatic polyester fiber, a liquid crystalline polymer fiber, an aromatic polyamide or a polyimide fiber.

These inorganic and organic fillers may be used alone or in combination of two or more. The combination of the fibrous filler and the granular or plate-like filler is an ideal combination particularly in terms of mechanical strength, dimensional accuracy, electrical properties and the like. The amount of the inorganic filler to be added is 120 parts by mass or less, preferably 20 to 80 parts by mass, per 100 parts by mass of the wholly aromatic polyester.

In particular, the glass fiber is preferably a fibrous filler, and the mica and the talc are plate-shaped fillers, and the amount thereof is 30 to 80 parts by mass based on 100 parts by mass of the wholly aromatic polyester. Further, the fiber length of the glass fiber is preferably 200 μm or more. The composition containing such a glass fiber in the above-mentioned exercise amount is particularly remarkable in the improvement of the heat distortion temperature, mechanical properties, and the like.

When these fillers are used, a sizing agent or a surface treatment agent can be used if necessary.

Further, other thermoplastic resins may be additionally added to the wholly aromatic polyester of the present invention in an amount which does not impair the intended purpose of the present invention.

Examples of the thermoplastic resin used in this state include aromatic dicarboxylic acids such as polyolefins such as polyethylene and polypropylene, polyethylene terephthalate, and polybutylene terephthalate. An aromatic polyester composed of an acid, a diol, or the like, a polyacetal (homo- or copolymer), polystyrene, polyvinyl chloride, polyamine, polycarbonate, ABS, polyphenylene oxide, polyphenylene Sulfide, fluororesin, etc. Further, these thermoplastic resins may be used in combination of two or more kinds.

<Polyester molded product>

The polyester molded article of the present invention is formed by molding the above-described wholly aromatic polyester of the present invention or the polyester resin composition of the present invention.

The polyester molded article of the present invention specifically exemplifies an electronic connector, a CPU socket, a relay switch component, a bobbin, an actuator, a noise reduction filter case, or a heating fixed press roll of an OA machine. Further, a polyester fiber or a polyester film is also cited. These can be formed by a conventional resin molding method using the wholly aromatic polyester of the present invention or the polyester resin composition of the present invention.

Further, as a specific form of the polyester molded article, a planar electronic connector is characterized in that it has a lattice structure inside the outer frame, and the interval between the lattice portions is 1.5 mm or less. Hereinafter, the planar electronic connector will be described in detail.

Various planar electronic connectors can be obtained by molding the wholly aromatic polyester of the present invention or the polyester resin composition of the present invention, but are particularly effective for the so-called lattice which cannot be industrially practical. A very thin-walled planar electronic connector in which the distance between the portions is 1.5 mm or less and the width of the resin portion of the lattice portion of the terminal is 0.5 mm or less and the height of the entire product is 5.0 mm or less.

When the planar electronic connector is described in more detail, the electronic connector shown in FIG. 1 which is formed in the embodiment has a frame portion having a thickness of 4.0 mm or less and a lattice portion having a thickness of 4.0 mm or less. The composition has a number of pin holes of several hundred in the product of 40 mm × 40 mm × 1 mm in the lattice portion. As shown in Fig. 1, the shape in which the distance between the lattice portions is 1.5 mm or less and the width of the resin portion of the holding terminal is 0.5 mm or less is extremely difficult to be formed by injection molding. Further, the planar electronic connector referred to in the present invention is also included in the lattice portion and has an opening of an appropriate size.

By using the wholly aromatic polyester or polyester resin group of the present invention As shown in Fig. 1, the gap between the lattice portions is 1.5 mm or less (1.2 mm) and the width of the resin portion of the lattice portion of the terminal is 0.5 mm or less (0.18 mm). The resin portion of the lattice portion has a very thin planar planar electronic connector, and the flatness thereof is also good.

If the flatness is numerically specified, it can be said that the peak temperature is 230 to 280 ° C, and the flatness before the IR remelting process for surface mounting is 0.05 mm or less and the flatness before and after remelting The difference of 0.10 mm or less is practical and has good flatness.

The molding method for obtaining an electronic connector having such a good flatness is not particularly limited, but it is preferable to use an economical injection molding method. In order to obtain an electronic connector having such a good flatness by injection molding, it is important to use the above-described wholly aromatic polyester of the present invention or the polyester resin composition of the present invention, but it is preferable. It is a forming condition in which the residual internal stress is small. In order to reduce the filling pressure and reduce the residual internal stress of the obtained electronic connector, the cylinder temperature of the forming machine is preferably a temperature higher than the melting point T°C of the wholly aromatic polyester, and is excessively high in the cylinder temperature. At this time, problems such as sagging of the nose of the cylindrical nozzle due to decomposition of the resin or the like occur, and therefore, the cylinder temperature is T°C~(T+30)°C, preferably T°C~(T+15). ) °C. Further, the mold temperature is preferably 70 to 100 °C. When the mold temperature is lowered, the resin composition is filled to cause a flow failure, which is unsatisfactory. When the mold temperature is excessively high, problems such as occurrence of burrs occur, which is undesirable. In terms of the ejection speed, it is preferable to form by 150 mm/sec or more. When the injection speed is low, there is a state in which only the unfilled molded article is obtained, or even if a molded article that is completely filled is obtained, the filling pressure is increased and remains. In the case of a molded article having a large internal stress, only the state of the electronic connector having poor flatness occurs.

[Examples]

Hereinafter, the present invention will be described in more detail by way of examples, but the invention is not limited thereto. Further, the physical property measurement and test methods in the examples are as follows.

[melting point]

The DSC manufactured by Perkinelmer Co., Ltd., after observing the observed endothermic peak temperature (Tm1) of the wholly aromatic polyester at room temperature and at a temperature rise of 20 ° C /min, at (Tm1 + 40) After maintaining the temperature of ° C for 2 minutes, the temperature was measured at a temperature of 20 ° C /min. After cooling to room temperature, the observed endothermic peak temperature was measured at a temperature of 20 ° C / min.

[crystallization temperature]

After observing the observed endothermic peak temperature (Tm1) of the wholly aromatic polyester and polyester resin composition at room temperature and 20 ° C /min, the DSC manufactured by Perkinelmer Co., Ltd. After the temperature was maintained at (Tm1 + 40) ° C for 2 minutes, the observed peak temperature of the heat was measured at a temperature drop of 20 ° C / minute.

[crystallization heat]

After observing the observed endothermic peak temperature (Tm1) of the wholly aromatic polyester and polyester resin composition at room temperature and 20 ° C /min, the DSC manufactured by Perkinelmer Co., Ltd. After maintaining at a temperature of (Tm1 + 40) ° C for 2 minutes, the measurement was carried out by using a cooling strip at 20 ° C / min. The heat generation peak heat obtained by measuring the peak of the observed peak temperature at the time of measurement.

[melt viscosity]

A wholly aromatic polyester and polyester resin composition was measured by a Capilograph (liquidity tester) manufactured by Toyo Seiki Co., Ltd. using an orifice plate having an inner diameter of 1 mm and a length of 20 mm at a temperature higher than the melting point of 10 to 20 ° C. The melt viscosity at a shear rate of 1000 sec ^{-1 was} calculated (according to ISO 11443).

[softening temperature]

A disc having a thickness of 1 mm was formed by hot stamping from a wholly aromatic polyester, and a fixed load of 12.7 MPa was applied to the molded article, and at a temperature of 20 ° C /min on a hot plate to apply A needle having a diameter of 1 mm to reach a temperature of 5% of the thickness of the molded article is used as the softening temperature.

[Determination of flatness of electronic connectors]

A polyester resin composition comprising an inorganic filler is injected by the following forming conditions ^. A planar electronic connector (the number of pin holes 750 pins) having an overall size of 39.82 mm × 41.82 mm × 1 mm t and a lattice pitch of 1.2 mm was formed as shown in Fig. 1 .

In addition, the gate uses a film gate starting from the long side of the length (the side of 41.82 mm) with a gate thickness of 0.3 mm.

The obtained electronic connector was placed on a horizontal table, and the height of the electronic connector was measured by a Quick Vision 404PROCNC image measuring machine manufactured by Mitsutoyo Corporation. At this time, from the end face of the electronic connector, the position of 0.5 mm was measured at intervals of 10 mm, and the difference between the maximum height and the minimum height was used as the flatness.

[Determination of Deformation Amount of Electronic Connector]

Further, IR remelting under the following conditions was carried out, and the flatness was measured by the above method, and the difference in flatness before and after remelting was determined as the amount of deformation of the electronic connector.

~Forming conditions~

Forming machine: Sumitomo Heavy Industries, Inc., SE30DUZ

Cylinder temperature: (nozzle) 370 ° C - 375 ° C - 360 ° C - 350 ° C (Examples 4 ~ 6)

340 ° C - 340 ° C - 330 ° C - 320 ° C (Comparative Example 8)

370 ° C - 375 ° C - 360 ° C - 350 ° C (Comparative Example 9)

350 ° C - 350 ° C - 340 ° C - 330 ° C (Comparative Example 10)

Mold temperature: 80 ° C

Injection speed: 300mm/sec

Pressure: 50MPa

Holding time: 2sec

Cooling time: 10sec

Spiral rotation number: 120rpm

Spiral back pressure: 1.2MPa

~IR remelting conditions~

Measuring machine: Large table flow soldering device RF-300 manufactured by Japan Pulse Technology Research Institute (using far infrared heater)

Sample conveying speed: 140mm/sec

Remelting furnace passage time: 5min

Temperature conditions Preheating zone: 150 °C, remelting zone: 225 °C, peak temperature: 287 °C

[Electrical connector minimum filling pressure]

In the shot ^. When the planar electronic connector of Fig. 1 is formed, the minimum injection filling pressure of a good molded article is obtained as the minimum filling pressure of the electronic connector.

[Load bending temperature]

They are shot separately by the following forming conditions ^. A polyester resin composition containing an inorganic filler was molded and measured in accordance with ISO 75-1, 2.

~Forming conditions~

Forming machine: Sumitomo Heavy Industries, Inc., SE100DU

Cylinder temperature: (nozzle) 370 ° C - 375 ° C - 360 ° C - 350 ° C (Examples 4 ~ 6)

340 ° C - 340 ° C - 330 ° C - 320 ° C (Comparative Example 8)

370 ° C - 375 ° C - 360 ° C - 350 ° C (Comparative Example 9)

350 ° C - 350 ° C - 340 ° C - 330 ° C (Comparative Example 10)

Mold temperature: 80 ° C

Injection speed: 2m/sec

Pressure: 50MPa

Holding time: 2sec

Cooling time: 10sec

Spiral rotation number: 120rpm

Spiral back pressure: 1.2MPa

[Fracture resistance]

A polyester resin composition comprising an inorganic filler is injected by the following forming conditions ^. The molded article for evaluation shown in Fig. 2 was formed.

The outer periphery of the injection molding product shown in Fig. 2 has a diameter of 23.6 mm, and inside the opening, 31 holes of 3.2 mm are opened, and the minimum wall thickness of the hole is 0.16 mm. The gate is a 3-point gate of the arrow section of Figure 1. In the observation of the fracture of the molded product, the occurrence of cracks around the hole was observed by a magnification of 5 times, and the state in which the molded article was broken was judged as "x", and the state in which no crack occurred was judged as "○".

~Forming conditions~

Forming machine: Sumitomo Heavy Industries, Inc., SE30DUZ

Cylinder temperature: (nozzle) 370 ° C - 375 ° C - 360 ° C - 350 ° C (Examples 4 ~ 6)

340 ° C - 340 ° C - 330 ° C - 320 ° C (Comparative Example 8)

370 ° C - 375 ° C - 360 ° C - 350 ° C (Comparative Example 9)

350 ° C - 350 ° C - 340 ° C - 330 ° C (Comparative Example 10)

Mold temperature: 140 ° C

Injection speed: 50mm/sec

Pressure: 100MPa

Holding time: 2sec

Cooling time: 10sec

Spiral rotation number: 120rpm

Spiral back pressure: 1.2MPa

[Example 1]

In a polymerization vessel equipped with a mixer, a reflux column, a monomer inlet, a nitrogen inlet, and a pressure reduction/outflow line, the following raw materials and metal contacts are charged. The medium and the oximation agent begin to replace the nitrogen.

(I) 4-hydroxybenzoic acid: 145 g (48 mol%) (HBA)

(II) 6-Hydroxy-2-naphthoic acid: 12 g (3 mol%) (HNA)

(III) Terephthalic acid: 89g (24.7 mole%) (TA)

(IV) Resorcinol: 8g (3.5 mole%) (RES)

(V) 4,4'-dihydroxybiphenyl: 85 g (20.8 mol%) (BP)

Potassium acetate catalyst: 15mg

Acetic anhydride: 229g

After the raw materials were charged, the temperature of the reaction system was raised to 140 ° C, and the reaction was carried out at 140 ° C for 3 hours. Then, the temperature is raised until 360 ° C, and the temperature is raised for 5.5 hours. From this point on, after 20 minutes, the pressure is reduced to 10 Torr (that is, 1330 Pa), and acetic acid, excess acetic anhydride, and other low-boiling components are distilled off. , performing melt polymerization. After the stirring torque reaches a predetermined value, nitrogen is introduced to start the pressure-reduced state, and after normal pressure, it is pressurized, and the polymer is discharged from the lower portion of the polymerization vessel.

The obtained polymer has a melting point of 357 ° C, a crystallization temperature of 298 ° C, a crystallization heat of 1.2 J / g, a softening temperature of 246 ° C, and a melt viscosity of 16 Pa. s.

The results of the measurement of the physical properties of the raw material monomers of the above Example 1 and the obtained polymer are shown in Table 1. Further, in Table 1, each raw material single system uses an abbreviation shown in the above parentheses of HBA, HNA or the like.

[Examples 2 to 3]

The polymerization was carried out in the same manner as in Example 1 except that the kind of the raw material monomer and the feed ratio were as shown in Table 1, from the lower portion of the polymerization vessel. To discharge the polymer. The results of the physical properties of the obtained polymer are shown in Table 1.

[Comparative Examples 1 to 7]

The polymerization was carried out in the same manner as in Example 1 except that the kind of the raw material monomer and the feed ratio were as shown in Table 1, and the polymer was discharged from the lower portion of the polymerization vessel. The results of the physical properties of the obtained polymer are shown in Table 1. Further, in Comparative Examples 6 and 7, the polymer was solidified in the reactor at the time of production, and it was impossible to produce a polymer having a desired molecular weight. Further, the APAP in Table 1 is 4-acetamidophenol.

It is understood from Table 1 that the softening temperature of the wholly aromatic polyester of Examples 1 to 3 is high, and the heat of crystallization is 1.8 J/g or less, which is excellent in resistance. Heat and toughness.

On the other hand, in Comparative Examples 1 and 5 in which RES was not used, and Comparative Example 2 in which HNA+RES (general formula (II) + (IV)) was less than 4 mol%, the toughness was deteriorated. Further, in Comparative Examples 3 and 4 in which HNA+RES (general formula (II) + (IV)) exceeded 10 mol%, heat resistance was deteriorated. Further, in Comparative Examples 6 and 7 in which the feed ratio of the raw material monomers (especially HBA) was outside the range of the present invention, the production of the polymer could not be performed.

[Example 4]

The following raw material monomers, metal catalysts, and deuteration agents were placed in a polymerization vessel equipped with a stirrer, a reflux column, a monomer inlet, a nitrogen inlet, and a reduced pressure/outflow line, and nitrogen substitution was started.

(I) 4-hydroxybenzoic acid: 1061 g (48 mol%) (HBA)

(II) 6-Hydroxy-2-naphthoic acid: 90 g (3 mol%) (HNA)

(III) Terephthalic acid: 657g (24.7 mole%) (TA)

(IV) Resorcinol: 62g (3.5 mole%) (RES)

(V) 4,4'-dihydroxybiphenyl: 620 g (20.8 mol%) (BP)

Potassium acetate catalyst: 110mg

Acetic anhydride: 1676g

After the raw materials were charged, the temperature of the reaction system was raised to 140 ° C, and the reaction was carried out at 140 ° C for 3 hours. Then, the temperature is raised up to the temperature of 360 ° C for 5.5 hours, and the acetic acid, excess acetic anhydride, and other low-boiling components are distilled off from the viewpoint of depressurization to 5 Torr (that is, 667 Pa) over 20 minutes. , performing melt polymerization. After the stirring torque reaches a predetermined value, nitrogen is introduced and the pressure is reduced, and the normal pressure is applied to the pressurized state. The lower portion of the polymerization vessel starts to discharge the polymer, and is granulated for the strand to be pelletized.

The obtained polymer has a melting point of 355 ° C, a crystallization temperature of 298 ° C, a crystallization heat of 1.2 J / g, and a melt viscosity of 10 Pa. s.

For the above-mentioned 100 parts by mass of the pellets, 33.3 parts by mass of a mixed mica (manufactured by Yamaguchi Mica Industries Co., Ltd., AB-25S, average particle diameter 25 μm) was obtained by a two-axis extruder to obtain a wholly aromatic group in the form of particles. Polyester resin composition. The obtained resin composition was subjected to various tests such as physical property measurement and "measurement of flatness of an electronic connector". The results are shown in Table 2.

[Example 5]

The polymer was obtained in the same manner as in Example 4 except that the kind of the raw material monomer and the feed ratio were as shown in Table 2. Next, granulation was carried out in the same manner as in Example 4. The obtained polymer has a melting point of 355 ° C, a crystallization temperature of 298 ° C, a crystallization heat of 1.2 J / g, and a melt viscosity of 10 Pa. s.

In addition, for the aforementioned particles of 100 parts by mass, by a two-axis extruder to practice ^. Mixing talc (made by Matsumura Industry Co., Ltd., crown talc PP, average particle size 12.8 μm) 23.1 parts by mass and glass fiber (made by Nippon Electric Glass Co., Ltd., ECS03T-786H, fiber diameter 10 μm, length 3 mm short bundle) 30.8 parts by mass, a wholly aromatic polyester resin composition in the form of a pellet was obtained. The obtained resin composition was subjected to various tests such as physical property measurement and "measurement of flatness of an electronic connector". The results are shown in Table 2.

[Embodiment 6]

In addition to the type of raw material monomer, the feed ratio is shown in Table 2 The rest were the same as in Example 4 to give a polymer. Next, granulation was carried out in the same manner as in Example 4. The obtained polymer has a melting point of 355 ° C, a crystallization temperature of 298 ° C, a crystallization heat of 1.2 J / g, and a melt viscosity of 10 Pa. s.

In addition, 100 parts by mass of the granules were combined by a two-axis extruder ^. 66.7 parts by mass of the glass fiber was kneaded to obtain a pellet-shaped wholly aromatic polyester resin composition. The obtained resin composition was subjected to various tests such as physical property measurement and "measurement of flatness of an electronic connector". The results are shown in Table 2.

[Comparative Examples 8 to 10]

In Comparative Examples 8 to 10, the polymer was obtained in the same manner as in Example 4 except that the kind of the raw material monomer and the feed ratio were as shown in Table 2. Next, granulation was carried out in the same manner as in Example 4. The polymer obtained in Comparative Example 8 had a melting point of 323 ° C, a crystallization temperature of 276 ° C, a crystallization heat of 2.0 J/g, and a melt viscosity of 12 Pa. s. Further, the polymer obtained in Comparative Example 9 had a melting point of 357 ° C, a crystallization temperature of 305 ° C, a crystallization heat of 2.1 J/g, and a melt viscosity of 10 Pa. s. Further, the polymer obtained in Comparative Example 10 had a melting point of 335 ° C, a crystallization temperature of 291 ° C, a crystallization heat of 3.1 J/g, and a melt viscosity of 20 Pa. s.

In addition, for the above-mentioned particles of 100 parts by mass, respectively, by a two-axis extruder ^. The kneading was as shown in Table 2 to obtain a pellet-shaped wholly aromatic polyester resin composition. The obtained resin composition was subjected to various tests such as physical property measurement and "measurement of flatness of an electronic connector". The results are shown in Table 2.

It is known from Table 2 that the planar electronic connectors of Examples 4 to 6 have good formability, small bending deformation, and good flatness, heat resistance and crack resistance. On the other hand, in Comparative Examples 8 to 10, it was impossible to make all the evaluations at the same time, which was a good result.

Claims (10)

A wholly aromatic polyester exhibiting optical anisotropy upon melting, characterized in that the essential structural components include the following general formulae (I), (II), (III), (IV), and The structural unit represented by V) is 35 to 75 mol% of the structural unit of (I), the structural unit of (II) is 2 to 8 mol%, and the structural unit of (III) is 8.5. ~31.5 Mohr%, the structural unit of (IV) is 2~8 mol%, the structural unit of (V) is 0.5~29.5 mol%, and the structural unit of (II)+(IV) is 4~10 moir %: For example, the wholly aromatic polyester of claim 1 wherein the melt viscosity of the shear rate of 1000 sec ^-1 is 1 × 10 ⁵ Pa at a temperature higher than the melting point of the wholly aromatic polyester by 10 to 40 ° C. s below. A wholly aromatic polyester according to claim 1 or 2, wherein the melting point is 280 to 390 °C. A polyester resin composition is prepared by blending 120 parts by mass or less of an inorganic or organic filler with 100 parts by mass of the wholly aromatic polyester according to any one of claims 1 to 3. The polyester resin composition of the fourth aspect of the invention, wherein the inorganic filler is one or more selected from the group consisting of glass fiber, mica and talc, and the amount of the binder is relative to the wholly aromatic polyester 100. It is 20 to 80 parts by mass in parts by mass. A polyester molded article, which is a wholly aromatic polyester according to any one of claims 1 to 3, or a polyester resin composition according to claim 4 or 5. The polyester molded article of claim 6, wherein the molded article is an electronic connector, a CPU socket, a relay switch component, a bobbin, an actuator, a noise reduction filter case, or a heating fixed pressure of an OA machine. Roller. The polyester molded article of claim 6, wherein the molded article has a lattice structure inside the outer frame, and the lattice portion has a structure in which the distance between the lattice portions is 1.5 mm or less. The polyester molded article of claim 6, wherein the molded article is a polyester fiber. The polyester molded article of claim 6, wherein the molded article is a polyester film.