阅读说明：本技术 强化热塑性聚酯树脂组合物 (Reinforced thermoplastic polyester resin composition ) 是由 清水隆浩 下拂卓也 于 2020-03-25 设计创作，主要内容包括：本发明涉及一种强化热塑性聚酯树脂组合物,其含有：聚对苯二甲酸丁二醇酯树脂(A)20～35质量份、聚对苯二甲酸乙二醇酯树脂(B)1～10质量份、共聚聚对苯二甲酸丁二醇酯树脂(C)1～10质量份、共聚聚对苯二甲酸乙二醇酯树脂(D)5～12质量份、聚碳酸酯系树脂(E)1～6质量份、纤维增强材料(F)45～60质量份以及酯交换抑制剂(G)0.05～2质量份,上述(A)、(B)、(C)、(D)、(E)以及(F)成分总计为100质量份；其可以在宽泛的成型条件下稳定地得到具有高刚性(弯曲模量超过30GPa)、高强度且增强材料的浮出等外观缺陷少、纹理外观均匀的成型品。(The present invention relates to a reinforced thermoplastic polyester resin composition comprising: 20 to 35 parts by mass of a polybutylene terephthalate resin (A), 1 to 10 parts by mass of a polyethylene terephthalate resin (B), 1 to 10 parts by mass of a copolymerized polybutylene terephthalate resin (C), 5 to 12 parts by mass of a copolymerized polyethylene terephthalate resin (D), 1 to 6 parts by mass of a polycarbonate resin (E), 45 to 60 parts by mass of a fiber-reinforcing material (F), and 0.05 to 2 parts by mass of an ester exchange inhibitor (G), the total of the components (A), (B), (C), (D), (E), and (F) being 100 parts by mass; it is possible to stably obtain a molded article having high rigidity (flexural modulus exceeding 30GPa), high strength, less appearance defects such as the emergence of a reinforcing material, and uniform texture and appearance under a wide range of molding conditions.)

1. A reinforced thermoplastic polyester resin composition comprising: 20 to 35 parts by mass of a polybutylene terephthalate resin (A), 1 to 10 parts by mass of a polyethylene terephthalate resin (B), 1 to 10 parts by mass of a copolymerized polybutylene terephthalate resin (C), 5 to 12 parts by mass of a copolymerized polyethylene terephthalate resin (D), 1 to 6 parts by mass of a polycarbonate resin (E), 45 to 60 parts by mass of a fiber-reinforcing material (F), and 0.05 to 2 parts by mass of an ester exchange inhibitor (G), wherein the total of the components (A), (B), (C), (D), (E), and (F) is 100 parts by mass, and the following requirements (1) and (2) are satisfied:

(1) the flexural modulus of a molded article obtained by injection molding of the reinforced thermoplastic polyester resin composition exceeds 30GPa,

(2) when the temperature-lowering crystallization temperature of the reinforced thermoplastic polyester resin composition as determined by a differential scanning calorimeter DSC is represented by TC2, TC2 is 165 ℃ or higher but lower than 190 ℃.

2. The reinforced thermoplastic polyester resin composition according to claim 1, wherein the fiber reinforcement (F) comprises flat-section glass fibers (F-1) having a fiber section with a ratio of a major axis to a minor axis, i.e., a major axis/minor axis of 1.3 to 8, and carbon fibers (F-2).

3. The reinforced thermoplastic polyester resin composition according to claim 1 or 2, wherein the copolymerized polybutylene terephthalate resin (C) contains at least one selected from the group consisting of isophthalic acid, sebacic acid, adipic acid, trimellitic acid, 2, 6-naphthalenedicarboxylic acid, ethylene glycol, diethylene glycol, neopentyl glycol, 1, 4-cyclohexanedimethanol, 1, 2-propanediol, 1, 3-propanediol, and 2-methyl-1, 3-propanediol as a copolymerization component.

4. The reinforced thermoplastic polyester resin composition according to any one of claims 1 to 3, wherein the copolymerized polybutylene terephthalate resin (C) contains 10 to 40 mol% of isophthalic acid as a copolymerization component, based on 100 mol% of the total acid components constituting the copolymerized polybutylene terephthalate resin.

5. The reinforced thermoplastic polyester resin composition according to any one of claims 1 to 4, wherein the copolymerized polyethylene terephthalate resin (D) contains at least one selected from the group consisting of isophthalic acid, sebacic acid, adipic acid, trimellitic acid, 2, 6-naphthalenedicarboxylic acid, diethylene glycol, neopentyl glycol, 1, 4-cyclohexanedimethanol, 1, 4-butanediol, 1, 2-propanediol, 1, 3-propanediol and 2-methyl-1, 3-propanediol as a copolymerization component.

6. The reinforced thermoplastic polyester resin composition according to any one of claims 1 to 5, wherein the copolymerized polyethylene terephthalate resin (D) contains neopentyl glycol in an amount of 20 to 60 mol% as a copolymerized component, assuming that the total diol component constituting the copolymerized polyethylene terephthalate resin (D) is 100 mol%.

7. A molded article having a surface textured appearance, comprising the reinforced thermoplastic polyester resin composition according to any one of claims 1 to 6.

Technical Field

The present invention relates to a reinforced polyester resin composition containing a thermoplastic polyester resin and a fiber reinforcement. More specifically, the present invention relates to a reinforced polyester resin composition which can give a molded article having high rigidity and high strength, less appearance defects due to, for example, the emergence of a fiber-reinforced material of the molded article, and a uniform texture appearance and a mirror surface appearance without wrinkles.

Background

Generally, polyester resins are widely used for automobile parts, electric and/or electronic parts, household miscellaneous goods, and the like because of their excellent mechanical properties, heat resistance, chemical resistance, and the like. Among them, it is known that the rigidity, strength and heat resistance of a polyester resin composition reinforced with an inorganic reinforcing material such as glass fiber are dramatically improved, and particularly, the rigidity is improved in accordance with the amount of the inorganic reinforcing material added.

However, when the amount of the inorganic reinforcing material such as glass fiber is large, the inorganic reinforcing material tends to be easily floated on the surface of the molded article, and in the case of the molded article requiring a glossy surface, the glossy surface may be low, and in the case of the molded article having a matte surface, the texture appearance defect may be a problem.

Particularly, polyester resins such as polybutylene terephthalate, which have a high crystallization rate, have poor transferability of a mold accompanying crystallization at the time of molding, and thus it is very difficult to obtain a satisfactory appearance.

On the other hand, as a method for obtaining a good texture appearance, a method of mixing an acrylic ester rubber-like polymer obtained by grafting a hydroxyl group-containing vinyl polymer to a polyester resin has been proposed (for example, patent documents 1 and 2). Since the rubber-containing graft polymer and the polyester resin are not well dispersed by simply mixing them, there is also a problem that the texture transfer is deteriorated and the texture is not uniform. The methods of patent documents 1 and 2 are effective for suppressing the unevenness of the texture, but the molded articles formed therefrom have a problem that the mechanical properties and the fluidity are low. Further, a method of modifying polybutylene terephthalate or a polycarbonate resin with isophthalic acid has been proposed (for example, patent documents 3 and 4). However, in patent document 3, if the filling amount is increased in order to obtain high mechanical strength and high rigidity, there is a drawback that the appearance is deteriorated. In patent document 4, since a large amount of the isophthalic acid-modified polybutylene terephthalate or polycarbonate resin is required, molding stability and molding cycle performance cannot be satisfied.

Although patent document 5 is proposed as an improvement to these drawbacks, it is recognized that there are also the following drawbacks that need to be improved: in applications where high rigidity is required, the rigidity is insufficient, and when a reinforcing material is added to increase the rigidity, the appearance is degraded, and further, the range of molding conditions is very narrow, and it is difficult to stably obtain good products.

In recent years, the molded products have been made thinner and longer, and further, higher rigidity has been demanded. Further, the appearance is required to have quality equal to or higher than that of the conventional art, and it is a very important subject to achieve balance between these qualities. As proposed in patent document 6, there are materials having a flexural modulus of more than 20GPa, but polyester materials having an ultrahigh rigidity of more than 30GPa and a good appearance have not been proposed so far.

Documents of the prior art

Patent document

Patent document 1 Japanese patent laid-open No. 2003-55414

Patent document 2 Japanese patent laid-open publication No. 2002-

Patent document 3 Japanese patent laid-open No. 2007-92005

Patent document 4 Japanese patent laid-open No. 2008-120925

Patent document 5 International publication No. 2015/008831

Patent document 6 Japanese patent laid-open publication No. 2017-39878

Disclosure of Invention

Problems to be solved by the invention

The present invention addresses the problem of providing a reinforced polyester resin composition that can provide a molded article having high rigidity (flexural modulus exceeding 30GPa), high strength, and a uniform texture appearance that is less susceptible to appearance defects and warpage deformation due to, for example, the emergence of inorganic reinforcing materials from the molded article, and that is free of wrinkles, and that can ensure a good molding cycle.

Means for solving the problems

The present inventors have intensively studied the composition and properties of a polyester resin composition in order to solve the above problems, and as a result, have found that the above problems can be achieved by containing a specific resin in an appropriate amount and accurately adjusting the ratio of each component, and have completed the present invention.

That is, the present invention has the following composition.

[1] A reinforced thermoplastic polyester resin composition comprising: 20 to 35 parts by mass of a polybutylene terephthalate resin (A), 1 to 10 parts by mass of a polyethylene terephthalate resin (B), 1 to 10 parts by mass of a copolymerized polybutylene terephthalate resin (C), 5 to 12 parts by mass of a copolymerized polyethylene terephthalate resin (D), 1 to 6 parts by mass of a polycarbonate resin (E), 45 to 60 parts by mass of a fiber-reinforcing material (F), and 0.05 to 2 parts by mass of an ester exchange inhibitor (G), wherein the total of the components (A), (B), (C), (D), (E), and (F) is 100 parts by mass, and the following requirements (1) and (2) are satisfied.

(1) The flexural modulus of a molded article obtained by injection molding of the reinforced thermoplastic polyester resin composition exceeds 30 GPa.

(2) When the temperature-lowering crystallization temperature of the reinforced thermoplastic polyester resin composition as determined by a Differential Scanning Calorimeter (DSC) is TC2 (. degree. C.), TC2 is 165 ℃ or more and less than 190 ℃.

[2] The reinforced thermoplastic polyester resin composition according to [1], wherein the fiber reinforcement (F) comprises a flat-section glass fiber (F-1) having a fiber section with a ratio of a major axis to a minor axis (major axis/minor axis) of 1.3 to 8, and a carbon fiber (F-2).

[3] The reinforced thermoplastic polyester resin composition according to [1] or [2], wherein the copolymerized polybutylene terephthalate resin (C) contains at least one selected from the group consisting of isophthalic acid, sebacic acid, adipic acid, trimellitic acid, 2, 6-naphthalenedicarboxylic acid, ethylene glycol, diethylene glycol, neopentyl glycol, 1, 4-cyclohexanedimethanol, 1, 2-propanediol, 1, 3-propanediol, and 2-methyl-1, 3-propanediol as a copolymerization component.

[4] The reinforced thermoplastic polyester resin composition according to any one of [1] to [3], wherein the copolymerized polybutylene terephthalate resin (C) contains 10 to 40 mol% of isophthalic acid as a copolymerization component, based on 100 mol of the total acid component constituting the copolymerized polybutylene terephthalate resin.

[5] The reinforced thermoplastic polyester resin composition according to any one of [1] to [4], wherein the copolymerized polyethylene terephthalate resin (D) contains at least one selected from the group consisting of isophthalic acid, sebacic acid, adipic acid, trimellitic acid, 2, 6-naphthalenedicarboxylic acid, diethylene glycol, neopentyl glycol, 1, 4-cyclohexanedimethanol, 1, 4-butanediol, 1, 2-propanediol, 1, 3-propanediol, and 2-methyl-1, 3-propanediol as a copolymerization component.

[6] The reinforced thermoplastic polyester resin composition according to any one of [1] to [5], wherein the copolymerized polyethylene terephthalate resin (D) contains neopentyl glycol in an amount of 20 to 60 mol% as a copolymerized component, assuming that the total diol component constituting the copolymerized polyethylene terephthalate resin (D) is 100 mol%.

[7] A molded article having a surface texture appearance, which comprises the reinforced thermoplastic polyester resin composition according to any one of [1] to [6 ].

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, even in the case of a resin composition in which a large amount of a fiber-reinforced material is blended, the curing (crystallization) rate (TC2 is an alternative parameter) of the resin composition in the mold is set to a specific range, whereby the fiber-reinforced material on the surface of the molded product can be suppressed from coming out, and the appearance of the molded product can be greatly improved. Further, by containing the specific fiber reinforcement in a specific range, a molded article having high strength, high rigidity and good mirror surface appearance can be obtained without greatly increasing the molding cycle, and in the case of a molded article having a texture, a molded article having a low brightness (gross) with a black-and-white feeling, uniform texture and very excellent design can be produced.

Detailed Description

The present invention will be described in detail below. In the following description, the content of each component constituting the reinforced thermoplastic polyester resin composition is expressed in parts by mass when the total of the components (a), (B), (C), (D), (E) and (F) is 100 parts by mass.

The polybutylene terephthalate resin (a) in the present invention is a resin that accounts for the main component of the entire polyester resins in the resin composition of the present invention. It is preferably contained at the maximum in the entire polyester resin. The polybutylene terephthalate resin (a) is not particularly limited, and a homopolymer composed of terephthalic acid and 1, 4-butanediol is preferably used. In addition, in the range where moldability, crystallinity, surface gloss and the like are not impaired, when the total acid component constituting the polybutylene terephthalate resin (a) is 100 mol% and the total diol component is 100 mol%, the other components may be copolymerized in an amount of about 5 mol%. Examples of the other component include those used for the copolymerized polybutylene terephthalate resin (C) described below.

The molecular weight of the polybutylene terephthalate resin (A) is preferably such that the reduced viscosity (measured by dissolving a 0.1g sample in 25ml of a mixed solution of phenol/tetrachloroethane (mass ratio 6/4) and measuring the solution at 30 ℃ C. using a Ubbelohde viscometer) is in the range of 0.5 to 0.8dl/g, more preferably 0.55 to 0.7dl/g, and still more preferably 0.6 to 0.7 dl/g. When the amount is less than 0.5dl/g, the toughness of the resin is low and the fluidity is too high, so that burrs tend to be easily formed. On the other hand, when it exceeds 0.8dl/g, it is difficult to apply uniform pressure to the texture-molded article due to the influence of the decrease in fluidity of the composition of the present invention, and therefore, it tends to be difficult to obtain a good texture appearance (the range of molding conditions is narrow).

The content of the polybutylene terephthalate resin (A) is 20 to 35 parts by mass, preferably 20 to 30 parts by mass, and more preferably 20 to 27 parts by mass. By blending the polybutylene terephthalate resin (a) within this range, various properties can be satisfied.

The polyethylene terephthalate resin (B) in the present invention is substantially a homopolymer of ethylene terephthalate units. In addition, when the total acid component and the total diol component constituting the polyethylene terephthalate resin (B) are 100 mol% and 100 mol%, respectively, the other components can be copolymerized in an amount of about 5 mol% within a range not to impair various properties. Examples of the other components include those used in the copolymerized polyethylene terephthalate resin (D) described below. As other components, diethylene glycol formed by condensation of ethylene glycol during polymerization is also included.

The molecular weight of the polyethylene terephthalate resin (B) is preferably such that the reduced viscosity (measured by dissolving 0.1g of a sample in 25ml of a mixed solvent of phenol/tetrachloroethane (mass ratio 6/4) and measuring the solution at 30 ℃ C. using an Ubbelohde viscometer) is 0.4 to 1.0dl/g, more preferably 0.5 to 0.9 dl/g. When the reduced viscosity is less than 0.4dl/g, the strength of the resin tends to be lowered, and when the reduced viscosity exceeds 1.0dl/g, the fluidity of the resin tends to be lowered.

The content of the polyethylene terephthalate resin (B) is 1 to 10 parts by mass, preferably 3 to 8 parts by mass. By blending the polyethylene terephthalate resin (B) within this range, various properties can be satisfied.

The copolymerized polybutylene terephthalate resin (C) in the present invention is a resin in which the proportion of 1, 4-butanediol is 80 mol% or more and the total proportion of terephthalic acid and 1, 4-butanediol is 120 to 190 mol% based on 100 mol% of the total acid component and 100 mol% of the total diol component. The copolymerization component may contain at least one selected from the group consisting of isophthalic acid, sebacic acid, adipic acid, trimellitic acid, 2, 6-naphthalenedicarboxylic acid, ethylene glycol, diethylene glycol, neopentyl glycol, 1, 4-cyclohexanedimethanol, 1, 2-propanediol, 1, 3-propanediol and 2-methyl-1, 3-propanediol.

Among them, isophthalic acid is preferable as a copolymerization component. In this case, the copolymerization ratio of isophthalic acid is preferably 10 to 40 mol%, more preferably 20 to 40 mol%, based on 100 mol% of the total acid components constituting the copolymerized polybutylene terephthalate resin (C). When the copolymerization ratio is less than 10 mol%, the transferability of the mold tends to be poor, and it tends to be difficult to obtain a sufficient appearance, and when the copolymerization ratio exceeds 40 mol%, the molding cycle is reduced and the releasability is lowered.

The molecular weight of the copolymerized polybutylene terephthalate resin (C) is preferably 0.4 to 1.5dl/g, more preferably 0.4 to 1.3dl/g, in reduced viscosity (measured by dissolving 0.1g of a sample in 25ml of a mixed solvent of phenol/tetrachloroethane (mass ratio 6/4) and measuring the solution at 30 ℃ C. using an Ubbelohde viscometer), though there is a slight difference depending on the specific copolymerization composition. When the reduced viscosity is less than 0.4dl/g, toughness tends to be lowered, and when the reduced viscosity exceeds 1.5dl/g, fluidity tends to be lowered.

The content of the copolymerized polybutylene terephthalate resin (C) is 1 to 10 parts by mass, preferably 2 to 8 parts by mass. When the content is less than 1 part by mass, appearance defects due to lifting of the fiber-reinforced material and transfer failure of the mold become conspicuous, and when the content exceeds 10 parts by mass, the molding cycle becomes long although the appearance of the molded article is good.

The copolymerized polyethylene terephthalate resin (D) in the present invention is a resin in which the proportion of ethylene glycol is 40 mol% or more and the total proportion of terephthalic acid and ethylene glycol is 80 to 180 mol% based on 100 mol% of the total acid component and 100 mol% of the total diol component. The copolymerization component may contain at least one selected from the group consisting of isophthalic acid, sebacic acid, adipic acid, trimellitic acid, 2, 6-naphthalenedicarboxylic acid, diethylene glycol, neopentyl glycol, 1, 4-cyclohexanedimethanol, 1, 4-butanediol, 1, 2-propanediol, 1, 3-propanediol, and 2-methyl-1, 3-propanediol, and is preferably amorphous. The copolymerization component is preferably 1, 4-butanediol of 20 mol% or less.

Among these, neopentyl glycol or a combination of neopentyl glycol and isophthalic acid is preferable as a copolymerization component from the viewpoint of various characteristics.

The copolymerization proportion of neopentyl glycol is preferably 20 to 60 mol%, more preferably 25 to 50 mol% when the total diol component constituting the copolymerized polyethylene terephthalate resin (D) is 100 mol%.

The copolymerization proportion of isophthalic acid is preferably 20 to 60 mol%, more preferably 25 to 50 mol%, based on 100 mol% of the total acid components constituting the copolymerized polyethylene terephthalate resin (D).

The molecular weight of the copolymerized polyethylene terephthalate resin (D) is preferably in the range of 0.4 to 1.5dl/g, more preferably 0.4 to 1.3dl/g, in terms of reduced viscosity (measured at 30 ℃ C. using an Ubbelohde viscometer by dissolving 0.1g of a sample in 25ml of a phenol/tetrachloroethane (mass ratio of 6/4)), although the molecular weight may vary slightly depending on the specific copolymerization composition. When the reduced viscosity is less than 0.4dl/g, toughness tends to be lowered, and when it exceeds 1.5dl/g, fluidity tends to be lowered.

The content of the copolymerized polyethylene terephthalate resin (D) is 5 to 12 parts by mass, preferably 6 to 11 parts by mass, and more preferably 7 to 11 parts by mass. When the amount is less than 5 parts by mass, appearance defects due to the floating of the fiber-reinforced material become conspicuous, and when the amount is more than 12 parts by mass, the molding cycle becomes long although the appearance of the molded article is good.

The polycarbonate in the polycarbonate-based resin (E) used in the present invention can be produced by a solvent method, that is, by a reaction of a dihydric phenol with a carbonate precursor such as phosgene or a transesterification reaction of a dihydric phenol with a carbonate precursor such as diphenyl carbonate in a solvent such as methylene chloride in the presence of a known acid acceptor and a molecular weight modifier. The dihydric phenol preferably used here is a bisphenol, in particular 2, 2-bis (4-hydroxyphenyl) propane, that is, bisphenol a. In addition, a part or all of bisphenol A may be substituted with other dihydric phenol. Examples of the dihydric phenol other than bisphenol A include compounds such as hydroquinone, 4' -dihydroxybiphenyl and bis (4-hydroxyphenyl) alkane, and halogenated bisphenols such as bis (3, 5-dibromo-4-hydroxyphenyl) propane and bis (3, 5-dichloro-4-hydroxyphenyl) propane. The polycarbonate may be a homopolymer using one dihydric phenol or a copolymer using two or more kinds thereof. The polycarbonate-based resin (E) is preferably a resin composed of only polycarbonate. The polycarbonate-based resin (E) may be a resin obtained by copolymerizing a component other than polycarbonate (for example, a polyester component) within a range (20% by mass or less) not impairing the effects of the present invention.

The polycarbonate-based resin (E) used in the present invention is particularly preferably high in fluidity, and the melt volume flow rate (unit: cm: 1.2kg) measured at 300 ℃ under a load of 1.2kg is preferably used³/10min) of 20 to 100, more preferably 25 to 95, and still more preferably 30 to 90. When the polycarbonate-based resin (E) having a melt volume flow rate of less than 20 is used, the fluidity is greatly reduced, and there is a problem that the stability of the strand is lowered and the moldability is deteriorated. When the melt volume flow rate exceeds 100, the physical properties are deteriorated due to too low a molecular weight, and gas generation due to decomposition is likely to occur.

The content of the polycarbonate resin (E) used in the present invention is 1 to 6 parts by mass, preferably 2 to 5 parts by mass. When the content is less than 1 part by mass, the effect of improving the texture appearance is small, and when the content exceeds 6 parts by mass, deterioration of the molding cycle due to decrease in crystallinity, appearance defects due to decrease in fluidity, and the like are more likely to occur.

The fiber reinforcement (F) used in the present invention is not particularly limited as long as it has a fibrous form, and specific examples thereof include glass fibers, carbon fibers, potassium titanate fibers, silica-alumina fibers, zirconia fibers, metal fibers, and the like. Among them, glass fiber and carbon fiber are preferable.

The glass fiber is preferably a ground fiber of a short glass fiber having an average fiber diameter of about 4 to 20 μm and a cut length of about 30 to 150 μm; the glass fiber has an average fiber diameter of about 1 to 20 μm and is cut into chopped strand-like glass fibers having a fiber length of about 1 to 20 mm. As the cross-sectional shape of the glass fiber, glass fibers having a circular cross-section and a non-circular cross-section can be used. As the glass fiber having a circular cross-sectional shape, a very general glass fiber having an average fiber diameter of about 4 to 20 μm and a cut length of about 2 to 6mm can be used. The non-circular cross-section glass fibers include glass fibers having an approximately elliptical shape, an approximately oblong shape, and an approximately cocoon shape in a cross section perpendicular to the longitudinal direction of the fiber length, and the flatness is preferably 1.3 to 8. Here, the flatness is a ratio of a major axis to a minor axis when a rectangle having a minimum area circumscribed about a cross section perpendicular to the longitudinal direction of the glass fiber is assumed, and the length of the major axis and the length of the minor axis of the rectangle are taken as the major axis and the minor axis, respectively. The thickness of the glass fiber is not particularly limited, and glass fibers having a short diameter of 1 to 20 μm and a long diameter of about 2 to 100 μm can be used.

The carbon fiber is not particularly limited as long as it has a fiber diameter of 3 to 10 μm and a tensile strength of 3.0GPa or more. The production method is not limited as long as it is a method generally disclosed, but PAN-based carbon fibers are preferable for improving mechanical properties. More preferably, the carbon fiber has a strength of 4.5GPa or more and a fiber diameter of 4.5 to 7.5 μm. The carbon fibers are preferably chopped strands obtained by cutting fiber bundles treated with a coupling agent or a sizing agent into 3 to 8mm pieces during the kneading. The upper limit of the strength of the carbon fiber is not particularly limited, and carbon fibers of 6.0GPa or less can be preferably used.

These fiber-reinforced materials (F) may be used alone in 1 kind, or may be used in combination in 2 or more kinds. The preferred form of the fiber reinforcement (F) is a combination of glass fibers and carbon fibers. In this case, when the total amount of the fiber reinforcement (F) is 100 mass%, the glass fiber is preferably 10 to 50 mass% and the carbon fiber is preferably 50 to 90 mass%.

When glass fibers and carbon fibers are used in combination, a more excellent effect can be exhibited when glass fibers having a flat cross section are used as the glass fibers. More preferably, the fiber reinforcement (F) is a combination of flat-section glass fibers (F-1) having a fiber section with a ratio of long diameter to short diameter (long diameter/short diameter) of 1.3 to 8 selected from the viewpoint of appearance and elastic modulus, and carbon fibers (F-2) selected from the viewpoint of rigidity. In this case, when the total amount of the fiber reinforcement (F) is 100% by mass, the flat-section glass fiber (F-1) is preferably 10 to 50% by mass, the carbon fiber (F-2) is preferably 50 to 90% by mass, the flat-section glass fiber (F-1) is more preferably 15 to 50% by mass, the carbon fiber (F-2) is preferably 50 to 85% by mass, the flat-section glass fiber (F-1) is more preferably 30 to 50% by mass, and the carbon fiber (F-2) is preferably 50 to 70% by mass.

The average fiber diameter and the average fiber length of the fibers can be measured by electron microscope observation.

As the glass fiber and the carbon fiber, those pretreated with a conventionally known coupling agent such as an organic silane compound, an organic titanium compound, an organic borane compound, and an epoxy compound can be preferably used.

In the reinforced thermoplastic polyester resin composition of the present invention, an inorganic reinforcing material other than the fiber reinforcing material (F) may be used in combination according to the purpose within a range not impairing the properties. Specific examples thereof include mica, wollastonite, needle-like wollastonite, glass flakes, glass beads and the like which are generally sold in retail, and those treated with a generally known coupling agent can be used without any problem. In the case of using the inorganic reinforcing materials other than the fiber reinforcing material (F) in combination, the total amount of the fiber reinforcing material (F) and the inorganic reinforcing materials other than the fiber reinforcing material (F) is defined as the content of the fiber reinforcing material (F) in consideration of the contents of the respective components of the reinforced thermoplastic polyester resin composition of the present invention. When the fiber reinforcement (F) and the other inorganic reinforcement are used in combination, the fiber reinforcement (F) is used preferably at least 50 mass%, more preferably at least 70 mass%, and still more preferably at least 80 mass%. However, as the inorganic reinforcing material, a material exhibiting a strong nucleating effect (for example, talc or the like) is not preferable because even a small amount of the inorganic reinforcing material is added, since it is out of the range of the temperature-decreasing crystallization temperature (TC2) of the material specified in the present invention.

The content of the fiber reinforcement (F) in the present invention is 45 to 60 parts by mass, preferably 50 to 60 parts by mass, from the viewpoint of rigidity, strength and appearance.

The reinforced thermoplastic polyester resin composition of the present invention can achieve a Charpy impact strength of a molded article obtained by injection molding of the reinforced thermoplastic polyester resin composition of 10kJ/m by setting the flat-section glass fiber (F-1) to 10 to 50 mass% and the carbon fiber (F-2) to 50 to 90 mass% when the total amount of the fiber reinforcement (F) is 100 mass%²The above. By setting the composition ratio of the fiber reinforcement (F), the fiber reinforcement (F) has high mechanical properties and also has a good appearance.

The transesterification inhibitor (G) used in the present invention is, as its name implies, a stabilizer for preventing the transesterification of the polyester resin. In the alloy between polyester resins, and the like, many transesterification reactions occur due to the heating process, regardless of how conditions at the time of production are optimized. If the degree is extremely large, the desired characteristics cannot be obtained by the alloy. Particularly, transesterification between polybutylene terephthalate and polycarbonate often occurs, and in this case, the crystallinity of polybutylene terephthalate is significantly reduced, which is not preferable. In the present invention, by adding the component (G), particularly, the transesterification reaction between the polybutylene terephthalate resin (a) and the polycarbonate-based resin (E) can be prevented, whereby appropriate crystallinity can be maintained.

As the ester interchange inhibitor (G), a phosphorus-based compound having an effect of deactivating the catalyst of the polyester-based resin can be preferably used, and for example, "ADEKA STAB AX-71" manufactured by ADEKA K.K.

The amount of the transesterification inhibitor (G) used in the present invention is 0.05 to 2 parts by mass, preferably 0.1 to 1 part by mass. When the amount is less than 0.05 parts by mass, the desired transesterification reaction inhibiting performance is often not exhibited, and on the contrary, when the amount is more than 2 parts by mass, the effect is hardly noticeable, and may be a factor such as an increase in gas.

The reinforced thermoplastic polyester resin composition of the present invention contains 45 to 60 parts by mass of the fiber reinforcement (F) in combination of the above components, and therefore, a molded article obtained by injection molding the reinforced thermoplastic polyester resin composition can have a flexural modulus exceeding 30 GPa.

The reinforced thermoplastic polyester resin composition of the present invention is characterized in that when the temperature-lowering crystallization temperature determined by a Differential Scanning Calorimeter (DSC) is represented by TC2, the value is in the range of 165 ℃ or more and less than 190 ℃. The TC2 is the peak top temperature of the crystallization peak of the thermogram obtained by heating to 300 ℃ at a heating rate of 20 ℃/min under a nitrogen gas flow using a Differential Scanning Calorimeter (DSC), holding the temperature for 5 minutes, and then cooling to 100 ℃ at a rate of 10 ℃/min. When TC2 is 190 ℃ or higher, the crystallization rate of the polyester resin composition increases, crystallization in the mold occurs too rapidly, and particularly, in a composition containing a large amount of the fiber-reinforced material, the propagation rate of the injection pressure tends to decrease, and the fiber-reinforced material is conspicuous on the surface of the molded article due to insufficient contact between the injection product and the mold and the influence of crystallization shrinkage, and the like, and the appearance of the molded article is deteriorated. In this case, although a method of setting the mold temperature at a high temperature of 120 to 130 ℃ to delay the curing of the molded article may be considered, this method can improve the surface gloss and appearance of the central portion in which the injection pressure is high in the mold, but is difficult to obtain a uniform and good appearance because defects such as the lifting of the fiber reinforcement are likely to occur in the end portion to which the injection pressure is hard to be applied. In addition, since the temperature of the molded product after being taken out from the mold becomes high, the warpage of the molded product becomes large.

On the other hand, when TC2 is less than 165 ℃, the crystallization rate becomes too low, and mold release failure and deformation at ejection due to adhesion to a mold or the like due to slow crystallization occur. Further, since the resin is likely to enter deeper into the texture by the pressure during molding, the depth of the texture is likely to be uneven due to displacement of the texture during shrinkage and demolding of the resin in the mold, and it is difficult to obtain a good texture appearance. In view of these problems in molding, the reinforced thermoplastic polyester resin composition of the present invention is adjusted to obtain the most suitable TC2, whereby good appearance and moldability can be obtained even at a mold temperature of 100 ℃ or lower.

The adjustment of TC2 can also be achieved by adjusting the content of the polyethylene terephthalate resin (B) or copolymerized polyethylene terephthalate resin (D). However, since these components also have a great influence on shrinkage, mold releasability, and the like, there is a problem that even if TC2 is brought within a target range by these adjustments, the range of molding conditions under which good appearance can be obtained is narrowed. In addition, even if a good appearance is obtained, there is a problem that the releasability is deteriorated. The reinforced thermoplastic polyester resin composition of the present invention can be molded under a wide range of molding conditions that can provide a good appearance without adversely affecting other properties by adjusting TC2 with the copolymerized polybutylene terephthalate resin (C) in a specific content. According to the present invention, by containing the fiber reinforcement (F) in an amount of more than 50 mass% based on 100 mass% of the reinforced thermoplastic polyester resin composition, even if the composition is such that the fiber reinforcement is very likely to come out, good appearance can be obtained under a very wide range of molding conditions by the mixing effect of the copolymerized polybutylene terephthalate resin (C).

Therefore, when the reinforced thermoplastic polyester resin composition of the present invention is molded at a mold temperature of about 100 ℃, a good surface appearance can be obtained at a wide injection speed under a wide range of molding conditions, and particularly, a molded article having a very black feeling and a uniform appearance without uneven texture can be obtained with respect to a mold to which a texture is applied.

In addition, the reinforced thermoplastic polyester resin composition of the present invention may contain various known additives as necessary within a range not impairing the characteristics of the present invention. Examples of the known additives include colorants such as pigments, mold release agents, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, plasticizers, modifiers, antistatic agents, flame retardants, and dyes. These various additives may be contained up to a total of 5% by mass, assuming that the reinforced thermoplastic polyester resin composition is 100% by mass. That is, the total of the above-mentioned components (A), (B), (C), (D), (E), (F) and (G) is preferably 95 to 100% by mass in 100% by mass of the reinforced thermoplastic polyester resin composition.

Examples of the release agent include long-chain fatty acids or esters and metal salts thereof, amide compounds, polyethylene wax, silicone, polyethylene oxide, and the like. The long-chain fatty acid is particularly preferably one having 12 or more carbon atoms, for example, stearic acid, 12-hydroxystearic acid, behenic acid, montanic acid, etc., and some or all of the carboxylic acids may be esterified with a mono-diol or a poly-diol, or may form a metal salt. Examples of the amide compound include ethylene bis-terephthalamide and methylene bis-stearamide. These mold release agents may be used alone or as a mixture.

The reinforced thermoplastic polyester resin composition of the present invention can be produced by mixing the above components and, if necessary, various stabilizers, pigments, etc. and melt-kneading them. The melt-kneading method may be any method known to those skilled in the art, and a single-screw extruder, a twin-screw extruder, a pressure kneader, a banbury mixer, or the like may be used. Among them, a twin-screw extruder is preferably used. As general melt kneading conditions, the barrel temperature of the twin-screw extruder is 240 to 290 ℃ and the kneading time is 2 to 15 minutes. However, in order to produce a resin composition in which the respective components are more uniformly dispersed and which is free from foreign matter aggregated due to dispersion failure, it is preferable that carbon fibers (F2) be supplied from a side inlet at 30 to 45 barrel positions on the more upstream side and melt-kneaded in a kneading zone at 2 or more, instead of the standard supply method of supplying a fiber reinforcement material such as glass fibers melt-kneaded only in 1 kneading zone from a side inlet at 50 to 80 barrel positions when the length of the barrel (バレル) from the main inlet position of the kneading apparatus to the die opening (ダイス) is 100 and the mixing start position is 0.

Examples

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. The measurement values described in the examples were measured by the following methods.

(1) Reduced viscosity of polyester resin

0.1g of the sample was dissolved in 25ml of a mixed solvent of phenol/tetrachloroethane (mass ratio 6/4) and measured at 30 ℃ using an Ubbelohde viscometer. (Unit: dl/g)

(2) Temperature reduction and crystallization temperature (TC2)

The peak top temperature of the crystallization peak of the thermogram was determined by using a Differential Scanning Calorimeter (DSC), raising the temperature to 300 ℃ at a temperature raising rate of 20 ℃/min under a nitrogen gas stream, holding the temperature for 5 minutes, and then lowering the temperature to 100 ℃ at a rate of 10 ℃/min.

(3) Appearance of molded article

When a 100mm × 100mm × 3mm molded article was molded by injection molding under conditions of a cylinder temperature of 275 ℃ and a mold temperature of 100 ℃, the mirror surface and texture appearance of the molded article molded at an injection speed range with a filling time of 1 second were visually observed. The texture was formed by using a mold for forming a pear-shaped texture having a depth of 15 μm. The results were "good" and "Δ", which were the levels without problems.

O: the surface of the glass fiber has no appearance defects caused by the protrusion or depression of the glass fiber, and the texture appearance is good

And (delta): some of the molded articles (particularly, the end portions of the molded articles) have some appearance defects, or have texture shifts, and have white-looking portions when viewed at different angles

X: the appearance defect of the whole molded product

(4) Releasability from mold

When molding was performed under the condition of (3) above, the cooling time after the end of the injection step was set to 5 seconds, and the mold release property was evaluated (the entire molding cycle was 17 seconds). The results were "good" and "Δ", which were the levels without problems.

O: the mold release was not problematic, and continuous molding was easy

And (delta): can be continuously molded while a single-shot molding failure occurs in several shots

X: poor demoulding can occur in each injection, and continuous molding cannot be realized

(5) Flexural Strength and flexural modulus

Measured according to ISO-178. The test piece was injection molded at a cylinder temperature of 270 ℃ and a mold temperature of 100 ℃.

(6) Charpy impact strength

Measured according to ISO-179. The test piece was injection molded at a cylinder temperature of 270 ℃ and a mold temperature of 100 ℃.

The components used in examples and comparative examples are as follows.

A polybutylene terephthalate resin (A);

(A-1) polybutylene terephthalate: reduced viscosity 0.58dl/g manufactured by Toyobo Co., Ltd

(A-2) polybutylene terephthalate: reduced viscosity 0.68dl/g manufactured by Toyobo Co., Ltd

A polyethylene terephthalate resin (B);

(B) polyethylene terephthalate: manufactured by Toyobo Co., Ltd., reduced viscosity of 0.63dl/g

A copolymerized polybutylene terephthalate resin (C);

(C-1) copolymerized polybutylene terephthalate: a sample of a copolymer having a composition ratio of TPA/IPA//1,4-BD (70/30// 100 mol%) and having a reduced viscosity of 0.73dl/g, Toyo Boseki (registered trademark)

(C-2) copolymerized polybutylene terephthalate: a sample of a copolymer having a composition ratio of TPA/IPA//1,4-BD (80/20// 100 mol%) and having a reduced viscosity of 0.80dl/g, Toyo Boseki (registered trademark)

A copolymerized polyethylene terephthalate resin (D);

(D) copolymerized polyethylene terephthalate: copolymer having a composition ratio of TPA// EG/NPG 100//70/30 (mol%), a sample product of Toyo Boseki Kabushiki Kaisha Toyo Boseki Kaisha having a reduced viscosity of 0.83dl/g

(abbreviations respectively indicate TPA: terephthalic acid, IPA: isophthalic acid, 1, 4-BD: 1, 4-butanediol, EG: ethylene glycol, NPG: neopentyl glycol component.)

A polycarbonate-series resin (E);

(E) polycarbonate (C): "Calibre 200-80" manufactured by Sundaura polycarbonate Co., Ltd., melt volume flow rate (300 ℃ C., load: 1.2kg)80cm³/10min

A fibrous reinforcement (F); (values of fiber diameter and fiber length measured by Electron microscope observation)

(F-1) glass fiber: "CSG 3PL 830S" manufactured by Nindon textile, flat cross section, ratio of major axis to minor axis: 2 (minor axis 10 μm, major axis 20 μm) and an average fiber length of 3mm

(F-2) carbon fiber: "CFUW-LC-HS" manufactured by Japan Polymer industries, fiber diameter 5.5 μm, cut length 6mm, tensile strength 5.5GPa

(F-3) glass fiber: "T-120H" manufactured by Nippon electric Nitri, circular cross section, average fiber length of 3mm, and average fiber diameter of 11 μm

A reinforcing material other than the fiber reinforcing material;

mica: "A-21S" by Shankou mica, having an average particle diameter of 23 μm (MV value by laser diffraction method)

A transesterification inhibitor (G);

(G) ester exchange inhibitor: "ADEKA STAB AX-71" manufactured by ADEKA corporation "

An additive;

stabilizer (antioxidant): ciba Japan "Irganox 1010"

Releasing agent: "LICOWAX-OP" manufactured by Claien Japan K.K.) "

Black pigment: ABF-T-9534 manufactured by RESINO COLOR "

Examples 1 to 9 and comparative examples 1 to 8

The reinforced polyester resin compositions of examples and comparative examples were prepared by weighing the above raw materials in the mixing ratios (parts by mass) shown in Table 1 and were usedA twin-screw extruder (manufactured by Toshiba machine Co., Ltd.) melted and kneaded at a cylinder temperature of 270 ℃ and a screw rotation speed of 200 rpm. The raw materials other than the reinforcing material were fed from the hopper into the twin-screw extruder, and the reinforcing material was fed from the exhaust port as a side feed (when 2 or more reinforcing materials were used, they were fed from the side feed port). The obtained pellets of the reinforced polyester resin composition were dried and then molded into various evaluation samples by an injection molding machine. The evaluation results are shown in table 1.

As is clear from Table 1, in examples 1 to 9, while having a high rigidity with a flexural modulus of 30GPa or more, good appearance can be obtained by setting TC2 to the range of 165 ℃ to TC2 to 190 ℃. Examples 1 and 6 had a tendency to have a poor appearance compared with the other examples.

On the other hand, in comparative examples 1 to 8, the properties, particularly the appearance, were inferior to those of the examples. That is, there is a problem that not only the degree of freedom for various shapes is small but also productivity is low because molding conditions for forming a good appearance are not found or there is a high possibility that a very narrow range is obtained.

Industrial applicability of the invention

According to the present invention, a molded article having high strength, high rigidity (flexural modulus exceeding 30GPa) and good surface appearance can be stably obtained in a wide range of molding conditions, and therefore, the present invention contributes significantly to the industry.