JP2019026683A - Polyester resin composition, thermoplastic resin composition containing the same, and molded article - Google Patents

Abstract

To provide a polyester resin composition having a low melt viscosity.SOLUTION: A polyester resin composition contains 30-95 pts.mass of (a) a polyester resin having a weight average molecular weight of 10,000 to 100,000, a melting point of 210°C or higher and a melt viscosity μ at a melting point +20°C of 70 Pa s or less, and 5-70 pts.mass of (b) a pigment. The weight average molecular weight Mw represents a relative weight average molecular weight relative to a molecular weight of standard polymethyl methacrylate determined by a gel permeation chromatography with hexafluoroisopropanol (addition of 0.005 N sodium trifluoroacetate) as a mobile phase.SELECTED DRAWING: None

Description

  The present invention relates to a polyester resin composition comprising a polyester resin and a pigment having a low melt viscosity and a high melting point, a thermoplastic resin composition containing the same, and a molded article comprising the thermoplastic resin composition.

  Polyester resins such as polybutylene terephthalate (PBT) and polyethylene terephthalate (PET) are excellent in mechanical properties, heat resistance, moldability recyclability, and chemical resistance, and can be melt processed into molded products, films and fibers. Furthermore, it is required to be colored according to the type of product.

  As the colorant for the resin, various colorants such as a dry color, a master batch, and a colored pellet are selectively used depending on the intended use, resin, and molding method. Among them, a master batch in which a pigment is dispersed at a high concentration in a resin is widely used in terms of excellent handling properties. On the other hand, in master batch production, it is important to knead the pigment into the resin at a high concentration and with good dispersibility. On the other hand, it is difficult to obtain a homogeneous master batch when using a pigment that easily forms an aggregate. there were. For this reason, a method is known in which pigment aggregation is suppressed by a pigment surface treatment or a pigment preliminary dispersion using a dispersant.

  In patent document 1, the dispersibility of the dye / pigment in a masterbatch is improved by using a low molecular weight thermoplastic polyester resin as a dye / pigment dispersion vehicle.

  In Patent Document 2, the dyeability of polyester fibers is improved by using a liquid polyester dispersant.

  In patent document 3, the dispersibility and coloring property at the time of highly filling a pigment are improved by using saturated copolyester.

JP 2001-64491 A JP-A-63-117071 JP-A-6-313096

  However, in the techniques of Patent Documents 1 to 3, since both use a low molecular weight and low melting point dispersant, the deterioration of the molding processability due to the slip effect of the dispersant and the bleedout of the dispersant in a high temperature environment, Furthermore, there was a problem that the manufacturing cost and productivity were inferior due to the necessity of the pigment treatment step. If a polyester resin excellent in pigment dispersibility and dispersibility can be used, a low-cost masterbatch can be easily produced.

  The problems to be solved by the present invention include a polyester resin composition comprising a polyester resin and a pigment having a low melt viscosity and a high melting point, a thermoplastic resin composition containing the polyester resin composition, and a molded article comprising the thermoplastic resin composition. It is to provide.

In order to solve the above problems, the polyester resin of the present invention has the following constitution. That is, the present invention is as follows.
(1) (a) 30 to 95 parts by mass of a polyester resin having a weight average molecular weight Mw of 10,000 to 100,000, a melting point of 210 ° C. or higher, and a melting viscosity μ at a melting point of + 20 ° C. of 70 Pa · s or less, (b) A polyester resin composition comprising 5 to 70 parts by mass of a pigment.
(However, the weight average molecular weight Mw used here is relative to the molecular weight of the standard polymethyl methacrylate obtained by gel permeation chromatography using hexafluoroisopropanol (0.005N sodium trifluoroacetate added) as a mobile phase). The weight average molecular weight is shown.)
(2) The polyester resin composition according to (1), wherein the polyester resin has a compound represented by the following formula (1) bonded to 30 to 150 mol / ton at the end.

(In the above formula (1), R ¹ is selected from an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms. At least one kind
R ² is one selected from a hydroxyl group, a carboxyl group, an amino group, a silanol group, and a thiol group,
m is an integer of 1 to 3,
n is an integer from 1 to 29;
X is a hydrogen atom and / or a methyl group,
Y is a hydrogen atom and / or a methyl group,
The total number of carbon atoms of the compound when excluding the carbon number of R ¹ and R ² is ² to 58. )
(3) The method for producing a polyester resin composition as described in (1) or (2) above, wherein the (a) polyester resin and (b) pigment are melt-kneaded in the range of 210 to 300 ° C.
(4) A thermoplastic resin composition comprising a thermoplastic resin and the polyester resin composition according to (1) or (2) above, comprising 0.01 to 10% by mass of the polyester resin composition, and 130 ° C. A thermoplastic resin composition characterized in that the weight loss rate after heat treatment for 100 hours is 0.1% or less.
(5) The thermoplastic resin according to (4), wherein the thermoplastic resin is at least one selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate. Composition.
(6) A method for producing a molded article comprising a thermoplastic resin composition comprising a thermoplastic resin and the polyester resin composition described in (1) or (2) above, wherein the thermoplastic resin composition is 230 to 320. A method for producing a molded product, comprising melt-molding in the range of ° C.
(7) A molded product obtained by molding the thermoplastic resin composition according to the above (4) or (5).

  According to the present invention, a polyester resin composition comprising a polyester resin and a pigment having a low melt viscosity and a high melting point, a thermoplastic resin composition containing the polyester resin composition, and a molded article comprising the thermoplastic resin composition can be obtained. .

  Next, the form for implementing this invention is demonstrated in detail.

  The polyester resin used in the present invention is obtained by reacting a diol or an ester-forming derivative thereof with a dicarboxylic acid or an ester-forming derivative thereof. Although there is no restriction | limiting in particular in the polymerization method about a polyester resin, The method obtained from diol and dicarboxylic acid is preferable. In the polyester resin of the present invention, the main diol component constituting the polyester resin portion is at least one selected from ethylene glycol and 1,4-butanediol, and the main dicarboxylic acid component is at least selected from terephthalic acid and dialkyl esters thereof. One type. Here, the main diol component is defined as a ratio of ethylene glycol and 1,4-butanediol to 80 mol% or more with respect to all diol components constituting the polyester resin of the present invention. The main dicarboxylic acid component is defined as a ratio of terephthalic acid and its dialkyl ester to 80 mol% or more with respect to all dicarboxylic acid components constituting the polyester resin of the present invention.

  As long as the effects of the present invention are not substantially impaired, the polyester resin in the present invention includes, as a copolymerization component, isophthalic acid, isophthalic acid-5-sulfonate, phthalic acid, naphthalene-2,6-dicarboxylic acid, Aromatic dicarboxylic acids such as bisphenol dicarboxylic acid and dialkyl esters thereof, succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, etc. 2 polymerizable functional groups such as diol components such as aliphatic dicarboxylic acids and dialkyl esters thereof, propanediol, pentanediol, hexanediol, 2-methyl-1,3-propanediol, and bisphenol A-ethylene oxide adduct May be copolymerized. These compounds are preferably in the range of 10% by weight or less based on all monomer components constituting the polyester resin. These compounds can be used alone or in combination of two or more. Examples of dicarboxylic acid dialkyl esters include dimethyl dicarboxylate and diethyl dicarboxylate. In addition, as a copolymerization component, the compound which has the said 2 polymerizable functional group is preferable. Since a compound having three or more polymerizable functional groups such as trimethyl 1,3,5-benzenetricarboxylate serves as a crosslinking point, the polymer melting point and melt residence stability tend to decrease. The weight ratio of the compound having three or more polymerizable functional groups contained in the polymer is preferably 0.8% by weight or less based on the total monomer components constituting the polyester resin. More preferably, it is 0.5% by weight or less, and further preferably 0% by weight.

  In the present invention, the weight average molecular weight (Mw) of the polyester resin needs to be 10,000 or more from the viewpoint of excellent mechanical properties of a molded product made of a resin composition containing the polyester resin. If it is less than 10,000, there is a problem that the mechanical strength is lowered. Moreover, it is preferable that it is 14,000 or more, and it is more preferable that it is 18,000 or more. Moreover, it is necessary that it is 100,000 or less at the point which can suppress the thermal deterioration at the time of manufacture. If it exceeds 100,000, there is a problem that the molding process becomes difficult. It is preferably 90,000 or less, and more preferably 80,000 or less. The weight average molecular weight is hexafluoroisopropanol (0) measured at 30 ° C. using hexafluoroisopropanol as a solvent and Shodex GPC HFIP-806M (two) and Shodex GPC HFIP-LG connected in series as a column. It can be measured by gel permeation chromatography (GPC) using .005N sodium trifluoroacetate as a mobile phase. The weight average molecular weight is a relative value to the molecular weight of standard polymethyl methacrylate. In addition, the number average molecular weight described later is also measured by the same method as described above.

  In the present invention, the melting point of the polyester resin needs to be 210 ° C. or higher. Moreover, it is preferable that it is 215 degreeC or more at the point which is excellent in melt workability, and it is more preferable that it is 220 degreeC or more. Although the upper limit of melting | fusing point is not specifically limited, It is preferable that it is 280 degrees C or less, and it is more preferable that it is 270 degrees C or less at the point which is excellent in melt workability. If the melting point is less than 210 ° C, there is a problem of lowering the heat resistance. On the other hand, if the melting point exceeds 280 ° C, the crystallinity and crystal size become extremely large. There is a problem in that the decomposition of the structure derived from the compound having the (poly) oxyalkylene structure represented by the formula (1) bonded to the terminal of the resin and the polyester resin is accompanied. The melting point of the polyester resin is a differential scanning calorimeter (DSC), heated from 30 ° C. to 280 ° C. at a heating rate of 20 ° C./min, held at 280 ° C. for 3 minutes, and then cooled down by 20 This is the peak top temperature of the endothermic peak observed when the temperature is decreased from 280 ° C. to 30 ° C. at a rate of 20 ° C./min and then increased from 30 ° C. to 280 ° C. at a rate of temperature increase of 20 ° C./min.

  Further, in the present invention, the heat of crystal fusion represented by the area of the endothermic peak measured under the above conditions using the differential scanning calorimeter (DSC) is 40 J / g or more in terms of excellent heat resistance. It is preferable that it is 45 J / g or more. Moreover, 60 J / g or less is preferable at the point which is excellent in melt processability, and 55 J / g or less is more preferable. The ratio of at least one selected from ethylene glycol and 1,4-butanediol to all diol components constituting the polyester resin of the present invention is 80 mol% or more, and the ratio of terephthalic acid and its alkyl ester to all dicarboxylic acid components is 80 mol%. By setting it as the above, the amount of heat of crystal fusion can be made high.

  Furthermore, the polyester resin of the present invention was heated from 30 ° C. to 280 ° C. at a temperature rising rate of 20 ° C./min using a differential scanning calorimeter (DSC), held at 280 ° C. for 3 minutes, and then the temperature falling rate of 20 It is preferable that the peak top temperature of the exothermic peak observed when the temperature is lowered from 280 ° C. to 30 ° C. at 30 ° C./minute (temperature-lowering crystallization temperature) is 160 ° C. or more from the viewpoint of excellent crystallinity. The temperature is more preferably 165 ° C or higher, and further preferably 170 ° C or higher. Moreover, it is preferable that it is 210 degrees C or less. When the temperature-falling crystallization temperature exceeds 210 ° C., the intermolecular interaction is strong and the melt viscosity reduction effect tends to be small. Therefore, the temperature-falling crystallization temperature is preferably 210 ° C. or less. The temperature is more preferably 200 ° C. or lower, and further preferably 190 ° C. or lower.

  The polyester resin of the present invention is required to have a melt viscosity μ (Pa · s) at a melting point of + 20 ° C. of 70 Pa · s or less from the viewpoint of excellent pigment dispersibility and distribution. When the melt viscosity is low, shear heat generation during polymerization is suppressed and decomposition can be suppressed. Therefore, the viscosity is preferably 60 Pa · s or less, and more preferably 50 Pa · s or less. In the present invention, the melt viscosity μ (Pa · s) at melting point + 20 ° C. is a vibration mode after melting at a melting point + 20 ° C. for 5 minutes in a nitrogen atmosphere using a rheometer (manufactured by Anton Paar, MCR501). The melt viscosity μ (Pa · s) when measured at a frequency of 3.0 Hz and a swing angle of 20%.

  In the present invention, the polyester resin preferably has a compound represented by the following formula (1) bound to 30 to 150 mol / ton at the end.

(In the above formula (1), R ¹ is selected from an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms. R ² is one selected from a hydroxyl group, a carboxyl group, an amino group, a silanol group, and a thiol group, m is an integer of 1 to 3, and n is an integer of 1 to 29. X is a hydrogen atom and / or a methyl group, Y is a hydrogen atom and / or a methyl group, and the total number of carbon atoms excluding the carbon number of R ¹ and R ² is ² to 58.)

  The compound having a (poly) oxyalkylene structure represented by the formula (1) has an ether bond having a high molecular mobility, and has a solubility parameter close to that of a polyester resin. Yes. Therefore, a compound having a (poly) oxyalkylene structure can reduce the intermolecular interaction of the polyester molecular chain at the time of melting and increase the free volume, thereby greatly increasing the molecular mobility of the polymer chain. . Therefore, a polyester resin composition having a low melt viscosity is obtained, and good distribution properties are exhibited. Dispensability is a measure of how much the master batch is evenly mixed with the dilution resin under certain molding processing conditions using a color master batch in which a pigment is kneaded at a high concentration. In addition, it is known that the distribution property becomes better as the melt viscosity of the color master batch is lower than the resin for dilution. Moreover, since the wettability with respect to a pigment is provided with the low surface tension and contact angle of a (poly) oxyalkylene structure, favorable pigment dispersibility is expressed.

In the present invention, R ¹ of the compound (1) is an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms. It is preferable that it is 1 type chosen. Specific examples of the alkyl group having 1 to 30 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group and the like. Specific examples of the cycloalkyl group having 6 to 20 carbon atoms include a cyclohexyl group, a cyclopentyl group, a cyclooctyl group, and a cyclodecyl group. Specific examples of the aryl group having 6 to 10 carbon atoms include a phenyl group, a tolyl group, a dimethylphenyl group, and a naphthyl group. Specific examples of the aralkyl group having 7 to 20 carbon atoms include benzyl group, phenethyl group, methylbenzyl group, 2-phenylpropan-2-yl group, diphenylmethyl group and the like. R ¹ is more preferably an alkyl group having 1 to 30 carbon atoms, and particularly preferably a methyl group.

In the present invention, R ² of the compound (1) is a functional group capable of binding to the polyester resin, and is preferably one type selected from a hydroxyl group, a carboxyl group, an amino group, a silanol group, and a thiol group. From the viewpoint of excellent reactivity with the polyester resin, a hydroxyl group and a carboxyl group are more preferable.

  In the present invention, m in the compound (1) is preferably an integer of 1 to 3 in terms of excellent heat resistance. Further, 1 or 2 is more preferable, and 1 is particularly preferable. By setting m to 3 or less, the ether bond occupying the terminal portion increases and the effect of improving pigment dispersibility can be increased.

  In the present invention, n in the compound (1) is preferably an integer of 1 to 29 from the viewpoint of excellent partitionability and melt residence stability due to reduction in melt viscosity. n is more preferably an integer of 3 or more, and particularly preferably an integer of 5 or more. n is more preferably an integer of 25 or less, and particularly preferably an integer of 20 or less. When n exceeds 29, the effect of improving the dispersibility by reducing the melt viscosity is reduced and the melt residence stability is deteriorated.

  In the present invention, X in the compound (1) is preferably a hydrogen atom and / or a methyl group. By making X a hydrogen atom and / or a methyl group, the affinity with the polyester portion serving as the main skeleton can be improved, and the effect of improving the distribution by reducing the melt viscosity can be increased.

  In the present invention, Y in the compound (1) is preferably a hydrogen atom and / or a methyl group. By using Y as a hydrogen atom and / or a methyl group, the affinity with the polyester portion serving as the main skeleton can be improved, and the effect of improving the distribution by reducing the melt viscosity can be increased.

  Here, X and Y are “a hydrogen atom and / or a methyl group”, respectively, when there are a plurality of repeating units having an oxyalkylene structure shown in parentheses in formula (1) (n is 2 to 29). In the case of an integer of X), X and Y in each repeating unit may independently be a hydrogen atom or a methyl group.

In the present invention, R ¹ and the carbon total number of the oxyalkylene structural portion excluding the number of carbon atoms in R ² of Compound (1) is preferably 2-58. By setting the total number of carbon atoms in the oxyalkylene structure portion excluding the carbon number of R ¹ and R ^{2 to 2} to 58, it is possible to obtain a polyester resin that is excellent in distribution properties and melt residence stability due to reduction in melt viscosity.

  In the present invention, a compound having a (poly) oxyalkylene structure represented by formula (1) when a polyester resin having a compound having a (poly) oxyalkylene structure represented by formula (1) at the terminal is obtained. It is preferable that a compounding quantity is 1 mass part or more with respect to a total of 100 mass parts of a polyester resin and the compound represented by Formula (1). By setting it as 1 mass part or more, the distribution improvement improvement effect by melt viscosity reduction can be enlarged. 2 parts by mass or more is more preferable, and 3 parts by mass or more is more preferable. Moreover, in order to make the molecular weight of a polyester resin high, it is preferable that it is 30 mass parts or less. The amount is more preferably 20 parts by mass or less, and further preferably 10 parts by mass or less. If the amount is less than 1 part by mass, the effect of reducing the melt viscosity is small and insufficient. On the other hand, if the amount exceeds 30 parts by mass, the heat resistance of the polyester resin is deteriorated.

  In the present invention, the concentration of the compound having a (poly) oxyalkylene structure represented by the formula (1) bonded to the terminal of the polyester resin is preferably in the range of 30 to 150 mol / ton. In order to increase the effect of improving the distribution by reducing the melt viscosity, it is more preferably 35 mol / ton or more, and particularly preferably 40 mol / ton or more. Moreover, in order to make the molecular weight of a polyester resin high, it is more preferable that it is 140 mol / ton or less, and it is especially preferable that it is 130 mol / ton or less. When the compound represented by the formula (1) bonded to the terminal of the polyester resin is less than 30 mol / ton, there is a problem that the effect of improving the distribution by reducing the melt viscosity is reduced, while the compound bonded to the terminal of the polyester resin. When the compound represented by (1) exceeds 150 mol / ton, there is a problem that it is difficult to increase the molecular weight and the melt residence stability is also lowered.

  In this invention, it is preferable that the weight ratio of the compound which has a (poly) oxyalkylene structure represented by Formula (1) couple | bonded with the terminal of the polyester resin with respect to a polyester resin is 1 weight% or more. By setting the content to 1% by weight or more, the effect of improving the distribution by reducing the melt viscosity can be increased. 2% by weight or more is more preferable, and 3% by weight or more is more preferable. Moreover, in order to make the molecular weight of a polyester resin high, it is preferable that it is 30 weight% or less. It is more preferably 20% by weight or less, and further preferably 10% by weight or less. If it is less than 1% by weight, the effect of reducing the melt viscosity is small and insufficient. On the other hand, if it exceeds 30% by weight, there is a problem that the heat resistance of the polyester resin is lowered.

  In the polyester resin of the present invention, it is preferable that a specific amount of a compound having a (poly) oxyalkylene structure represented by the formula (1) is bonded to the polymer terminal. By bonding the compound represented by the formula (1) to the polymer terminal, the molecular mobility during melting can be improved without impairing the crystallinity of the polyester resin as the main skeleton, and the melt viscosity is remarkable. To reduce.

  When a compound having mainly a (poly) oxyalkylene structure is bonded to the main chain as part of a repeating unit, both ends of the (poly) oxyalkylene structure are constrained compared to when the compound is bonded mainly to the terminal. As a result, there is a tendency that sufficient molecular mobility improvement effect cannot be expressed. Further, the temperature lowering crystallization temperature tends to decrease and the crystallinity tends to decrease. On the other hand, it is possible to suppress a decrease in crystallinity by bonding a compound having a (poly) oxyalkylene structure represented by the formula (1) to the terminal of the polyester resin. Furthermore, since the (poly) oxyalkylene structure and the polyester structure have an ordered microphase separation-like structure by being bonded to the terminal, various additives are easily concentrated at high concentrations. When it is contained, it is possible to express long-term storage stability and melt residence stability higher than conventional.

  In the polyester resin composition of the present invention, the blending amount of the (a) polyester resin is 30 parts by mass or more with respect to 100 parts by mass in total of the (a) polyester resin and (b) pigment in terms of excellent pigment dispersibility. It is necessary. In order to develop good color developability, the amount is preferably 40 parts by mass or more, more preferably 50 parts by mass or more, and particularly preferably 60 parts by mass or more. Further, it is necessary to be 95 parts by mass or less in terms of excellent pigment dispersibility. In order to develop good color developability, it is preferably 94 parts by mass or less, more preferably 93 parts by mass or less, and particularly preferably 92 parts by mass or less. If the amount is less than 30 parts by mass, the pigment is not uniformly kneaded into the resin, and there is a problem that uniform pellets cannot be obtained. On the other hand, when the amount exceeds 95 parts by mass, the pigment concentration is low, and there are many polyester resin compositions necessary for producing a sufficient color, and there is a problem that the manufacturing cost and productivity are inferior.

  Although the pigment used for the polyester resin composition of this invention is not specifically limited, A well-known organic pigment, an inorganic pigment, an extender pigment, etc. can be used. As organic pigments, azo pigments such as condensed azo, anthraquinone, perinone, perylene, selenium such as thioindigo, phthalocyanine such as phthalocyanine blue and phthalocyanine green, quinacridone, dioxazine, isoindolinone, Examples include pyrrolopyrrole, aniline black, and organic fluorescent pigments. Examples of inorganic pigments include natural products such as clay, barite and mica, ferrocyanides such as bitumen, sulfides such as zinc sulfide, sulfates such as barium sulfate, chromium oxide, zinc white, titanium white, petal, iron black Oxides such as aluminum hydroxide, hydroxides such as aluminum hydroxide, silicates such as calcium silicate and ultramarine, carbonates such as calcium carbonate and magnesium carbonate, carbon such as carbon black and graphite, aluminum powder, bronze powder, zinc powder Metal powders such as the above, and other calcined pigments. Examples of extender pigments include calcium carbonate, barium sulfate, and talc. These pigments may be used in combination of two or more. Moreover, you may use together the pigment containing a dispersing agent in the range which does not impair the effect of this invention. Dyes can also be used as long as the effects of the present invention are not impaired.

  In the polyester resin composition of the present invention, the blending amount of the (b) pigment is 5 parts by weight or more with respect to a total of 100 parts by weight of the (a) polyester resin and (b) pigment in terms of excellent pigment dispersibility. is necessary. In order to develop good color developability, the amount is preferably 6 parts by mass or more, more preferably 7 parts by mass or more, and particularly preferably 8 parts by mass or more. Moreover, it is required that it is 70 mass parts or less at the point which is excellent in pigment dispersibility. In order to develop good color developability, it is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, and particularly preferably 40 parts by mass or less. If the amount is less than 5 parts by mass, the concentration of the pigment is low, and there are many polyester resin compositions necessary for producing a sufficient color, resulting in inferior production costs and productivity. On the other hand, when the amount exceeds 70 parts by mass, there is a problem that the pigment is not kneaded uniformly into the resin and a uniform pellet cannot be obtained.

  The polyester resin composition of the present invention preferably contains 0.1 to 5.0% by weight of an antioxidant in order to suppress oxidative degradation of the compound having a polyoxyalkylene structure. 0.2 weight% or more is more preferable, and 0.3 weight% or more is further more preferable. 4.0 weight% or less is more preferable and 3.0 weight% or less is still more preferable at the point which suppresses decomposition | disassembly of the polyester resin by antioxidant. If it is less than 0.1% by weight, the effect of suppressing oxidative degradation is insufficient. On the other hand, if it exceeds 5.0% by weight, there is a problem of a decrease in heat resistance. The antioxidant is not particularly limited, and specific examples include hindered phenol-based, sulfur-based, hydrazine-based, and triazole-based antioxidants. These may be used alone or in combination of two or more.

  As the hindered phenol-based antioxidant, pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], thiodiethylenebis [3- (3,5-di-t) -Butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 4,6-bis (octylthiomethyl) -o-cresol, and the like. It is done. Among these, pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (IRGANOX1010: manufactured by Ciba Japan) is preferable because it has a high effect of suppressing coloring.

  Sulfur-based antioxidants include dilauryl thiodipropionate, ditridecyl thiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, pentaerythritol tetrakis (3-lauryl thiopropionate) And pentaerythritol-tetrakis (3-dodecylthiopropionate).

  Examples of hydrazine-based antioxidants include decamethylene dicarboxylic acid-bis (N′-salicyloyl hydrazide), bis (2-phenoxypropionyl hydrazide) isophthalate, N-formyl-N′-salicyloyl hydrazine, and the like. Is mentioned.

  Examples of triazole antioxidants include benzotriazole and 3- (N-salicyloyl) amino-1,2,4-triazole.

  The temperature at which the (a) polyester resin and the (b) pigment of the present invention are melt-kneaded is preferably 210 ° C. or higher, more preferably 220 ° C. or higher, from the viewpoint that it can be uniformly melt-kneaded. It is particularly preferable that the temperature be 230 ° C or higher. In addition, the temperature at which the polyester resin and the pigment of the present invention are melt-kneaded is preferably 300 ° C. or less from the viewpoint that aggregation of the pigment can be suppressed, and 290 ° C. or less from the point that thermal decomposition of the polyester resin can be suppressed. Is more preferable, and 280 ° C. or lower is particularly preferable.

  The method of melt kneading of the polyester resin composition of the present invention is not particularly limited, but a method in which a resin and various additives are premixed and then supplied to an extruder or the like and sufficiently melt kneaded, or a weight feeder, etc. And a method in which a predetermined amount of each component is supplied to an extruder or the like and sufficiently melt-kneaded.

  Examples of the preliminary mixing include a dry blending method and a mixing method using a mechanical mixing device such as a tumbler, a ribbon mixer, and a Henschel mixer.

  The polyester resin composition of the present invention is preferably molded after being pelletized. As a pelletizing method, a single-screw extruder equipped with a screw, a twin-screw extruder, a tri-screw extruder, a conical extruder, a kneader type kneader, etc. are used to discharge into a strand and cut with a strand cutter. A method is mentioned.

  In the thermoplastic resin composition of the present invention, the mass ratio of the polyester resin composition is preferably 0.01% by mass or more with respect to the thermoplastic resin composition. By setting the content to 0.01% by mass or more, a thermoplastic resin composition having good color development can be obtained. 0.05 mass% or more is more preferable, and 0.1 mass% or more is further more preferable. Moreover, in order not to impair the characteristic of the thermoplastic resin composition obtained, it is preferable that it is 10 mass% or less. It is more preferably 5% by mass or less, and further preferably 1% by mass or less. If it is less than 0.01% by mass, uneven coloring tends to occur. On the other hand, if it exceeds 10% by mass, the production cost increases and the properties of the thermoplastic resin contained in the thermoplastic resin composition change. is there. Finally, a thermoplastic resin composition containing 0.01 to 10% by mass of the polyester resin of the present invention with respect to the thermoplastic resin composition can be obtained.

  By blending the polyester resin composition of the present invention into a thermoplastic resin as a master batch and melt-molding it, it is possible to obtain a molded article of a thermoplastic resin composition having good color developability of films, fibers and other various shapes. it can. Examples of the melt molding method include injection molding, extrusion molding and blow molding, and injection molding is particularly preferably used.

  As injection molding methods, gas assist molding, two-color molding, sandwich molding, in-mold molding, insert molding, and injection press molding are known in addition to the usual injection molding methods. it can.

  The temperature at which the thermoplastic resin and the polyester resin composition of the present invention are melt-molded is preferably 230 ° C. or higher, more preferably 240 ° C. or higher, in view of being able to melt and knead uniformly. It is especially preferable to make it above. In addition, the temperature at which the thermoplastic resin and the polyester resin composition of the present invention are melt-molded is preferably 320 ° C. or less in terms of suppressing aggregation of the pigment, and 310 ° C. in terms of suppressing thermal decomposition of the polyester resin. It is more preferable to make it below, and it is especially preferable to set it below 300 degreeC.

  The thermoplastic resin is one selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and polybutylene naphthalate in terms of ease of melt kneading with the polyester resin composition. The above is preferable.

  It is also possible to melt-knead the thermoplastic resin of the present invention and the polyester resin composition to obtain pellets of the thermoplastic resin composition.

  When the thermoplastic resin composition of the present invention is processed into various products, various additives such as a lubricant, an antistatic agent, a flame retardant, an ultraviolet absorber, an antibacterial agent, and the like are within the range not impairing the effects of the present invention. One or more additives such as a nucleating agent, a matting agent, a plasticizer, a release agent, an antifoaming agent, or other additives may be added as necessary.

  The thermoplastic resin composition obtained according to the present invention can reduce color unevenness and is excellent in color developability. Therefore, it can be melt-processed by a known method to various products such as fibers, films, bottles, and injection molded products having excellent appearance. Can do.

Hereinafter, the present invention will be described specifically by way of examples.
<Pigment>
(B-1): β-type phthalocyanine blue (Pigment Blue 15: 3) manufactured by Tokyo Chemical Industry Co., Ltd.
(B-2): Copolymerized polyester Byron GM415 manufactured by Toyobo Co., Ltd. and β-type phthalocyanine blue (Pigment Blue 15: 3) manufactured by Tokyo Chemical Industry Co., Ltd. were blended at a weight ratio of 1: 1, and the pigment was blended with a three-roll mill at 130 ° C. Dispersed pigment containing dispersant (B-3): Kinacridone (Pigment Violet 19) manufactured by Tokyo Chemical Industry Co., Ltd.

(1) Weight average molecular weight, number average molecular weight, dispersity The values of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyester resin and the thermoplastic resin were determined by gel permeation chromatography (GPC). These average molecular weights are values in terms of standard polymethyl methacrylate. The degree of dispersion is a value (Mw / Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn). A WATERS differential refractometer WATERS410 was used as a detector, a MODEL510 high-performance liquid chromatography was used as a pump, and Shodex GPC HFIP-806M (two) and Shodex GPC HFIP-LG were used as columns. Hexafluoroisopropanol (0.005N-sodium trifluoroacetate added) was used as a solvent, and a solution in which the sample concentration was 1 mg / mL was prepared. The flow rate was 1.0 mL / min, and 0.1 mL of the solution was injected for analysis.

(2) Melt viscosity μ
Using a rheometer (manufactured by Anton Paar, MCR501), 0.5 g of a sample dried for 12 hours or more in a hot air dryer at 110 ° C. was melted at a melting point + 20 ° C. for 5 minutes in a nitrogen atmosphere, and then a vibration mode, a frequency of 3.0 Hz The melt viscosity μ (Pa · s) of the polyester resin was measured at a swing angle of 20%.

(3) introduction of the compound into the polymer terminal (1) ⁽¹ H-NMR measurement)
The polyester resin was subjected to ¹ H-NMR measurement using an FT-NMR JNM-AL400 manufactured by JEOL Ltd. at a total number of 256 times. A solution having a sample concentration of 50 mg / mL was used using deuterated HFIP (hexafluoroisopropanol) as a measurement solvent. The integrated intensity of the peak derived from the R ¹ and R ² portions of the compound represented by the formula (1) and the peak derived from the polyester component that is the main skeleton of the polyester resin is calculated, and the number of hydrogen atoms in each structural unit The composition ratio was determined by dividing by and the amount (mol / ton) of compound (1) introduced into the polyester resin was calculated.

(4) Introduction rate of compound (1) to polymer terminal The total terminal group weight calculated by multiplying the reciprocal of the number average molecular weight obtained by (1) by 2000000 is X (mol / ton), according to (3) above. Y × 100 / X (%) was calculated with Y (mol / ton) being the amount of compound (1) introduced into the obtained polymer terminal.

(5) Thermal characteristics Thermal characteristics were measured using a differential scanning calorimeter (DSC7) manufactured by PerkinElmer. Heat generated when 5 mg of sample was heated from 30 ° C. to 280 ° C. at a rate of 20 ° C./min in a nitrogen atmosphere, held at 280 ° C. for 3 minutes, and lowered from 280 ° C. to 30 ° C. at a rate of 20 ° C./min. The peak top temperature of the peak was the cooling crystallization temperature Tc, and the area of the exothermic peak was the cooling crystallization heat amount ΔHc. Subsequently, the peak top temperature of the endothermic peak when the temperature was raised from 30 ° C. to 280 ° C. at a rate of 20 ° C./min was defined as the melting point Tm, and the peak area of the endothermic peak as the crystal melting heat amount ΔHm.

(6) Tensile strength Injection time and holding time are 10 seconds and cooling time is 10 seconds under molding temperature melting point + 20 ° C. and mold temperature 80 ° C. using an injection molding machine NEX1000 manufactured by Nissei Plastic Industry Co., Ltd. The tensile yield strength of an ISO3167 (A type) dumbbell test piece obtained by molding a thermoplastic resin composition under the molding cycle conditions was measured using an autograph AG-20-kNX manufactured by Shimadzu Corporation. The measurement was performed 5 times, and the average value was taken as the tensile yield strength. It shows that it has the outstanding mechanical strength, so that this tensile strength is large.

(7) Bleed-out resistance 1 g of a sample was weighed in an aluminum cup, and the weight reduction rate after heat treatment in a gear oven at 130 ° C. for 100 hours was measured.

(8) Pigment dispersibility Using an injection molding machine TR30EHA manufactured by Sodick, the injection time and the holding time are 5 seconds and the cooling time is 40 seconds under the respective conditions of the molding temperature melting point + 20 ° C. and the mold temperature 80 ° C. For a square plate having a thickness of 0.5 mm and 3 mm × 3 mm obtained by molding a thermoplastic resin composition under molding cycle conditions, a 200 × magnification, 15 mm × 15 mm using a digital microscope VHX-5000 manufactured by Keyence Corporation. Among them, the observation was performed 20 times while changing the visual field, and the total number of coarse particles having a particle diameter of 20 μm or more was counted. The case where the number of coarse particles was less than 5 was evaluated as ◯, the case where it was 5 or more and less than 10 as Δ, and the case where it was 10 or more as x.

(9) Distributiveness (color unevenness)
Using Sodick's injection molding machine TR30EHA, thermoplasticity under molding cycle conditions of molding temperature melting point + 20 ° C and mold temperature 80 ° C, injection time and holding time of 5 seconds, and cooling time of 40 seconds. About square plate of thickness 0.5mm and 3mmx3mm obtained by shape | molding a resin composition, the value of (DELTA) E measured using the Nippon Denshoku Industries Co., Ltd. spectrocolorimeter SE2000 is less than 1.6. The case was evaluated as ◯, the case of 1.6 or more and less than 3.2 was evaluated as Δ, and the case of 3.2 or more was determined as ×.

(10) Stretchability The thermoplastic resin composition was dried at 130 ° C. in a vacuum dryer for 12 hours or more and then pressed at 280 ° C. to obtain a press film having a thickness of 0.1 mm. The obtained press film was subjected to simultaneous biaxial stretching (stretching ratio 3 × 3) at a stretching temperature of 70 ° C. and a stretching speed of 60% / min using an automatic biaxial stretching device manufactured by Imoto Seisakusho. Those that could be stretched without tearing were judged as ◯, and those with tearing were judged as ×.

Example 1
After heating 100 g of 1,4-butanediol (BDO) to 100 ° C., 11.2 g of tetra-n-butoxy titanate (TBT) was mixed to obtain a catalyst solution.

780 g of terephthalic acid (TPA) as the dicarboxylic acid component, 760 g of BDO as the diol component, 45.0 g of the compound represented by the above formula (1) having the (poly) oxyalkylene structure described in Table 1 (100 parts by mass of polybutylene terephthalate to be produced) 4.0 parts by mass), 4.6 mL of the catalyst solution obtained by the above method as an esterification reaction catalyst was charged into a reactor equipped with a rectifying column. At this time, the molar ratio of BDO to TPA (BDO / TPA) was 1.8, and the amount of TBT added to 100 g of polybutylene terephthalate to be produced was 1.3 × 10 ⁻⁴ mol (0.000 parts by mass of polybutylene terephthalate). 045 parts by mass). After starting the esterification reaction under a reduced pressure of 160 ° C. and 93 kPa, the temperature was gradually raised, and finally the esterification reaction was carried out for 285 minutes at a temperature of 225 ° C. As a polycondensation reaction catalyst in the obtained reaction product, 0.5 × 10 ⁻² mol (0.05 parts by mass with respect to 100 parts by mass of polybutylene terephthalate) with respect to 100 g of polybutylene terephthalate produced by the addition of TBT, Then, 0.49 mL of the catalyst solution obtained by the above method was added, and the polycondensation reaction was performed for 230 minutes under the conditions of a temperature of 245 ° C. and a pressure of 100 Pa. When the predetermined stirring torque was reached, the reaction system was purged with nitrogen. After returning to normal pressure, the polycondensation reaction was stopped, discharged in a strand form, cooled, and immediately cut to obtain polyester resin pellets.

  As shown in Table 1, the obtained polyester resin and pigment were pre-blended. Thereafter, the mixture was supplied to a twin screw extruder (TEX30α-45 manufactured by Nippon Steel Works) set to cylinder temperature: melting point + 20 ° C. and screw rotation speed: 200 rpm, and melt kneaded. A polyester resin composition was obtained by pelletizing the extruded gut.

  As shown in Table 1, the resulting polyester resin composition was pre-blended with a terminal unmodified polybutylene terephthalate having Mw = 21,000 as a thermoplastic resin. Thereafter, an injection molded product of the thermoplastic resin composition was obtained by melt molding. Table 1 shows the properties of the obtained thermoplastic resin composition. The hexafluoroisopropanol solution in which the polyester resin is dissolved is gradually added to a place where 10 times the amount of methanol is being stirred and reprecipitated, whereby the unreacted formula (1) is obtained. The compound was removed. The precipitate was recovered and dried in a vacuum dryer at room temperature for 3 hours or more. From the NMR spectrum of the polymer after reprecipitation purification, the compound represented by the formula (1) introduced into the polymer terminal was quantified.

(Examples 2 to 16 and Comparative Examples 1 to 6)
It carried out like Example 1 except having changed the kind of compound to be used, and manufacturing conditions as shown in Tables 1-3.

  As described in Tables 1 to 3, the thermoplastic resin compositions of Examples 1 to 16 were compared with the thermoplastic resin compositions of Comparative Examples 1 to 6 in mechanical properties, bleed-out resistance, pigment dispersibility, and distribution. The property was good.

(Example 17)
Magnesium acetate equivalent to 60 ppm in terms of magnesium atom, 100 g of dimethyl terephthalate, and 59.2 g of ethylene glycol were melted in a nitrogen atmosphere at 150 ° C., and the temperature was raised to 240 ° C. over 4 hours with stirring. Then, methanol was distilled off and transesterification was performed to obtain bis (hydroxyethyl) terephthalate.

  After maintaining the esterification reaction vessel charged with 110 g of the obtained bis (hydroxyethyl) terephthalate at a temperature of 250 ° C., 143 g of terephthalic acid, 61.5 g of ethylene glycol, and the (poly) oxyalkylene structure described in Table 3 were used. 12.7 g of the compound represented by the formula (1) (the compound represented by the formula (1) is 4.0 parts by mass with respect to 100 parts by mass of the total amount of bis (hydroxyethyl) terephthalate, terephthalic acid, and ethylene glycol). ) Was sequentially supplied over 4 hours, and after completion of the supply, an esterification reaction was further performed over 1 hour to obtain an esterification reaction product.

  The obtained esterification reaction product was put into a test tube and kept in a molten state at 250 ° C., and then the resulting polymer was antimony trioxide equivalent to 250 ppm in terms of antimony atoms and phosphorus equivalent to 50 ppm in terms of phosphorus atoms. Acid, cobalt acetate equivalent to 6 ppm in terms of cobalt atom was added as an ethylene glycol solution. Thereafter, the reaction system was decompressed while stirring at 90 rpm to start the reaction. The reactor was gradually heated from 250 ° C. to 290 ° C., and the pressure was reduced to 110 Pa. The time to reach the maximum temperature and final pressure was both 60 minutes. When the predetermined stirring torque was reached, the reaction system was purged with nitrogen and returned to normal pressure to stop the polycondensation reaction, discharged in a strand form, cooled, and immediately cut to obtain polymer pellets. The time from the start of decompression to the arrival of the predetermined stirring torque was 3 hours 00 minutes.

  As shown in Table 4, the obtained polyester resin and pigment were pre-blended. Thereafter, the mixture was supplied to a twin screw extruder (TEX30α-45 manufactured by Nippon Steel Works) set to cylinder temperature: melting point + 20 ° C. and screw rotation speed: 200 rpm, and melt kneaded. A polyester resin composition was obtained by pelletizing the extruded gut.

  As shown in Table 4, as the obtained polyester resin composition and thermoplastic resin, terminal unmodified polyethylene terephthalate having Mw = 21,000 was pre-blended. Thereafter, an injection molded product of the thermoplastic resin composition was obtained by melt molding. Table 4 shows the properties of the obtained thermoplastic resin composition. The hexafluoroisopropanol solution in which the polyester resin is dissolved is gradually added to a place where 10 times the amount of methanol is being stirred and reprecipitated, whereby the unreacted formula (1) is obtained. The compound was removed. The precipitate was recovered and dried in a vacuum dryer at room temperature for 3 hours or more. From the NMR spectrum of the polymer after reprecipitation purification, the compound represented by the formula (1) introduced into the polymer terminal was quantified.

(Examples 18 to 23 and Comparative Examples 7 to 11)
The same procedure as in Example 17 was conducted, except that the types of compounds used and production conditions were changed as shown in Tables 4 and 5.

  As shown in Tables 4 and 5, the thermoplastic resin compositions of Examples 17 to 23 had mechanical properties, bleed-out resistance, pigment dispersibility, and distribution as compared with the thermoplastic resin compositions of Comparative Examples 7 to 11. The property was good.

  Since the polyester resin composition of the present invention is excellent in pigment dispersibility and dispersibility due to the low melt viscosity of the polyester resin, it can be melt-processed by a known method to various products such as fibers, films, bottles and injection molded products. Can do. These products are useful for agricultural materials, horticultural materials, fishery materials, civil engineering / architectural materials, stationery, medical supplies, automotive parts, electrical / electronic components or other uses.

Claims (7)

(A) 30 to 95 parts by mass of a polyester resin having a weight average molecular weight Mw of 10,000 to 100,000, a melting point of 210 ° C. or higher, and a melting viscosity + 20 ° C. of 70 Pa · s or less, and (b) pigment 5 A polyester resin composition comprising -70 parts by mass.
(However, the weight average molecular weight Mw used here is relative to the molecular weight of the standard polymethyl methacrylate obtained by gel permeation chromatography using hexafluoroisopropanol (0.005N sodium trifluoroacetate added) as a mobile phase). The weight average molecular weight is shown.) The polyester resin composition according to claim 1, wherein the polyester resin has a compound represented by the following formula (1) bonded to 30 to 150 mol / ton at the terminal.
(In the above formula (1), R ¹ is selected from an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms. At least one kind
R ² is one selected from a hydroxyl group, a carboxyl group, an amino group, a silanol group, and a thiol group,
m is an integer of 1 to 3,
n is an integer from 1 to 29;
X is a hydrogen atom and / or a methyl group,
Y is a hydrogen atom and / or a methyl group,
The total number of carbon atoms of the compound when excluding the carbon number of R ¹ and R ² is ² to 58. ) The method for producing a polyester resin composition according to claim 1 or 2, wherein the (a) polyester resin and (b) pigment are melt-kneaded in a range of 210 to 300 ° C. A thermoplastic resin composition comprising a thermoplastic resin and the polyester resin composition according to claim 1, comprising 0.01 to 10% by mass of the polyester resin composition, and heat-treated at 130 ° C. for 100 hours. The thermoplastic resin composition is characterized in that the weight reduction rate of is 0.1% or less. The thermoplastic resin composition according to claim 4, wherein the thermoplastic resin is at least one selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate. A method for producing a molded article comprising a thermoplastic resin composition comprising a thermoplastic resin and the polyester resin composition according to claim 1, wherein the thermoplastic resin composition is melt-molded in a range of 230 to 320 ° C. The manufacturing method of the molded article characterized by doing. A molded article formed by molding the thermoplastic resin composition according to claim 4 or 5.