JP6139946B2 - Polyester resin composition - Google Patents

Description

  The present invention relates to a polyester-based resin composition, and specifically relates to a polyester-based resin composition having excellent releasability.

  Polyester resins such as polybutylene terephthalate resin and polyethylene terephthalate resin have excellent properties as engineering plastics such as excellent heat resistance, moldability, chemical resistance and electrical insulation. As the center, it is widely used for electrical and electronic parts, automobile parts, other electrical parts, machine parts and the like.

Thermoplastic resins such as polyester resins improve the releasability from the mold at the time of molding and suppress contamination of the mold. In order to suppress deterioration of physical properties, a release agent is generally contained.
In recent years, productivity has been increased by shortening the injection molding cycle, that is, high cycle properties have become particularly important, and polyester-based resin compositions having excellent high cycle properties have been demanded.

  It is proposed that an aliphatic carboxylic acid metal salt (Patent Documents 1 and 2), a fatty acid ester, paraffin (Patent Document 3), polyethylene wax (Patent Document 4), or the like be blended with a polyester resin as a release agent. Has been. However, in the polyester resin composition containing such a release agent, it is necessary to lengthen the cooling time, and if the cycle is increased, the molded product may be damaged during the extraction stage, or the molded product may be deformed or abnormal. It is difficult to achieve dimensional uniformity.

Japanese Patent Publication No. 47-32435 Japanese Patent Publication No. 48-4097 JP 51-39756 A Japanese Patent Laid-Open No. 10-310689

  An object of the present invention is to provide a polyester-based resin composition that is excellent in releasability, high cycle, and excellent dimensional uniformity of a molded product.

The present inventor uses the high melting point release agent (B) and the low melting point release agent (C) in combination as the release agent, thereby solving the above-described problems, excellent release properties, and high cycle. The present inventors have found that a molded product with good dimensional uniformity of the molded product can be stably manufactured even if the manufacturing process is completed.
The present invention provides the following polyester resin compositions.

[1] Containing a polyester resin (A), a release agent (B) having a melting point of 130 ° C. or less by a differential scanning calorimeter (DSC) and a release agent (C) having a melting point of 180 ° C. or more. A polyester resin composition characterized by the above.
[2] The polyester resin according to [1], wherein the content ratio (B) / (C) of the content of the release agent (B) and the release agent (C) is 3/7 to 8/2. Composition.
[3] The above [1] or [2], wherein the content of the release agent (B) and the release agent (C) is 0.1 to 3 parts by mass in total with respect to 100 parts by mass of the polyester resin (A). ] The polyester-type resin composition of description.
[4] The polyester resin composition according to any one of [1] to [3], wherein the release agent (B) is an oxidized polyethylene wax.
[5] The polyester resin composition according to any one of [1] to [4], wherein the release agent (C) is a carboxylic acid amide wax.

  According to the resin composition of the present invention, the mold release agent (B) having a high melting point of a specific temperature or higher and the mold release agent (C) having a low melting point of a specific temperature or lower are used in combination, thereby providing excellent mold release properties. It is possible to provide a polyester-based resin material that can be made into a high cycle and is excellent in dimensional uniformity of a molded product obtained even when molded in a high cycle.

It is a perspective view which shows the shape of the box formation type | mold product used for the release property evaluation in the Example and comparative example of this invention. It is a top view which shows the box formation type article and ejector pin which were shown in FIG. FIG. 3 is an explanatory view showing the position of the ejector pin at the bottom of the box-shaped product.

[Summary of Invention]
The polyester-based resin composition of the present invention comprises a polyester resin (A), a release agent (B) having a melting point of 130 ° C. or less by a differential scanning calorimeter (DSC), and a release agent having a melting point of 180 ° C. or more. (C) is contained.

Hereinafter, embodiments of the present invention will be described in detail. The following description may be made based on embodiments and specific examples, but the present invention is not construed as being limited to such embodiments and specific examples.
In the specification of the present application, “to” is used in the sense of including the numerical values described before and after it as the lower limit value and the upper limit value.

[Polyester resin (A)]
As the polyester resin (A) which is the main component of the polyester resin composition of the present invention, polycondensation of a dicarboxylic acid compound and a dihydroxy compound, polycondensation of an oxycarboxylic acid compound, or polycondensation of a mixture of these compounds. The resulting thermoplastic polyester resin may be either a homopolyester or a copolyester.
Examples of the dicarboxylic acid compound constituting the polyester resin include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylethane dicarboxylic acid and other alicyclic dicarboxylic acids, and cyclohexane dicarboxylic acid. And aliphatic dicarboxylic acids such as adipic acid and sebacic acid.

  As is well known, these can be used in polycondensation reactions as ester-forming derivatives such as dimethyl esters in addition to free acids. Examples of the oxycarboxylic acid include paraoxybenzoic acid, oxynaphthoic acid, and diphenyleneoxycarboxylic acid. These can be polycondensed alone, but are often used in a small amount together with a dicarboxylic acid compound.

  As the dihydroxy compound, aliphatic diols such as ethylene glycol, propylene glycol, butanediol, neopentyl glycol, and polyoxyalkylene glycol are mainly used. Hydroquinone, resorcin, naphthalenediol, dihydroxydiphenyl ether, 2,2-bis (4 Aromatic diols such as -hydroxyphenyl) propane and cycloaliphatic diols such as cyclohexanediol can also be used.

  In addition to these bifunctional compounds, trifunctional or higher polyfunctional compounds such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane are introduced to introduce a branched structure. A small amount of a monofunctional compound such as a fatty acid can also be used.

  The polyester resin (A) used in the resin composition of the present invention is usually a polycondensate mainly composed of a dicarboxylic acid compound and a dihydroxy compound, that is, a structural unit which is an ester of a dicarboxylic acid compound and a dihydroxy compound in calculation. The resin occupies preferably 70% by mass or more, more preferably 90% by mass or more. The dicarboxylic acid compound is preferably an aromatic dicarboxylic acid, and the dihydroxy compound is preferably an aliphatic diol.

  Among these, as the polyester resin (A), polyalkylene terephthalate in which 95 mol% or more of the acidic component is terephthalic acid and 95 mol% or more of the alcohol component is an aliphatic diol is preferable. Typical examples thereof are polybutylene terephthalate and polyethylene terephthalate, which are close to homoesters, that is, 95% by mass or more of the entire resin is composed of a terephthalic acid component and 1,4-butanediol or ethylene glycol component. Preferably there is. In the present invention, polybutylene terephthalate is preferred.

  Polybutylene terephthalate may contain a dicarboxylic acid unit other than terephthalic acid. Specific examples of other dicarboxylic acids include isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, and 2,5-naphthalenedicarboxylic acid. Acid, 2,6-naphthalenedicarboxylic acid, biphenyl-2,2′-dicarboxylic acid, biphenyl-3,3′-dicarboxylic acid, biphenyl-4,4′-dicarboxylic acid, bis (4,4′-carboxyphenyl) Aromatic dicarboxylic acids such as methane, anthracene dicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 4,4′-dicyclohexyldicarboxylic acid, and adipine Aliphatic dicarboxylic acids such as acid, sebacic acid, azelaic acid and dimer acid Kind, and the like.

  The diol unit may contain other diol units in addition to 1,4-butanediol. Specific examples of the other diol units include aliphatic or alicyclic diols having 2 to 20 carbon atoms. And bisphenol derivatives. Specific examples include ethylene glycol, propylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, decamethylene glycol, cyclohexanedimethanol, 4,4'-dicyclohexylhydroxymethane. 4,4′-dicyclohexylhydroxypropane, bisphenol A ethylene oxide addition diol, and the like. Furthermore, triols such as glycerin and trimethylolpropane are also included.

  The polybutylene terephthalate is preferably a polybutylene terephthalate homopolymer obtained by polycondensation of terephthalic acid and 1,4-butanediol. In addition, as the carboxylic acid unit, one or more dicarboxylic acids other than the above terephthalic acid and / or A polybutylene terephthalate copolymer containing one or more diols other than the 1,4-butanediol as the diol unit may be used. In the polybutylene terephthalate, the proportion of terephthalic acid in the dicarboxylic acid unit is preferably 70 mol% or more, more preferably 90 mol% or more, from the viewpoint of mechanical properties and heat resistance. Similarly, the proportion of 1,4-butanediol in the diol unit is preferably 70 mol% or more, more preferably 90 mol% or more.

  In addition to the above-mentioned bifunctional monomers, trifunctional monomers such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane are introduced to introduce a branched structure, and fatty acids are used for molecular weight control. A small amount of a monofunctional compound can be used in combination.

Polybutylene terephthalate is produced by batch polymerization or continuous polymerization of a dicarboxylic acid component mainly composed of terephthalic acid or an ester derivative thereof and a diol component mainly composed of 1,4-butanediol. be able to. In addition, after a low molecular weight polybutylene terephthalate resin is produced by melt polymerization, solid state polymerization can be performed under a nitrogen stream or under reduced pressure to increase the degree of polymerization (or molecular weight) to a desired value.
The polybutylene terephthalate is preferably produced by a continuous melt polycondensation of a dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of 1,4-butanediol.

  The catalyst used in performing the esterification reaction may be a conventionally known catalyst, and examples thereof include a titanium compound, a tin compound, a magnesium compound, and a calcium compound. Of these, titanium compounds are particularly preferred. Specific examples of the titanium compound as the esterification catalyst include titanium alcoholates such as tetramethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate, and titanium phenolates such as tetraphenyl titanate.

The polybutylene terephthalate may be a polybutylene terephthalate resin modified by copolymerization. As a specific preferred copolymer thereof, polyalkylene glycols (particularly, polytetramethylene glycol (PTMG)) are copolymerized. Polyester ether resin, dimer acid copolymerized polybutylene terephthalate resin, particularly isophthalic acid copolymerized polybutylene terephthalate resin. These copolymers are those having a copolymerization amount of 1 mol% or more and less than 50 mol% in all segments of polybutylene terephthalate. Among them, the copolymerization amount is preferably 2 to 50 mol%, more preferably 3 to 40 mol%, further preferably 4 to 30 mol%, and particularly preferably 5 to 20 mol%.
And the preferable content of these copolymers is 1-40 mass% in the total amount of 100 mass% of polyester resin (A), Furthermore, 3-30 mass%, Especially 5-20 mass%.

  Moreover, it is also preferable to use what added the polyethylene terephthalate to the polybutylene terephthalate as the polyester resin (A) used for this invention.

  The intrinsic viscosity ([η]) of the polyester resin (A) may be appropriately selected and determined. Usually, it is preferably 0.5 to 2 dl / g, among which the moldability and mechanical properties of the resin composition are preferred. In view of the above, it is preferably 0.6 to 1.5 dl / g. If a material having an intrinsic viscosity of 0.5 dl / g or more is used, the mechanical strength of a molded product obtained from the resin composition tends to be sufficiently high, and if it is 2 dl / g or less, the fluidity of the resin composition is improved. However, the moldability tends to be improved.

  In the present specification, the intrinsic viscosity of the polyester resin is a value measured at 30 ° C. in a 1: 1 (mass ratio) mixed solvent of tetrachloroethane and phenol.

[Release agent (B)]
The release agent (B) is a release agent having a melting point of 130 ° C. or less as determined by differential scanning calorimetry (DSC).
In this specification, the melting point refers to the melting point by differential scanning calorimetry (DSC), and refers to the peak temperature (° C.) of the main peak of melting. Specifically, it refers to the peak top temperature (° C.) of the exothermic main peak detected when the temperature is raised from 30 ° C. to the expected melting point + 40 ° C. at 20 ° C./min.
A mold release agent (B) is mix | blended with a polyester resin (A), and has a function which improves a mold release property so that a molded article can peel easily from a metal mold | die. Specifically, a stable and smooth extrusion process is possible without causing problems such as deformation or breakage of the molded product during extrusion after the molten resin filled in the mold has solidified. It will be.

  Preferred examples of the release agent (B) include natural waxes, polyolefin compounds, fatty acid ester compounds, and silicone compounds.

  Examples of natural waxes include carnauba wax and beeswax refined wax.

  Examples of the polyolefin compound include compounds selected from paraffin wax and polyethylene wax. Among them, polyethylene having a mass average molecular weight of 700 to 10000, more preferably 900 to 8000, from the viewpoint of good dispersion of the polyolefin compound. Wax is preferred.

Polyolefin compounds include carboxyl groups (carboxylic acid (anhydride) groups, ie, carboxylic acid groups and / or carboxylic anhydride groups; the same shall apply hereinafter), haloformyl groups, ester groups, carboxylate metal bases, hydroxyl groups. It is preferable to add a functional group having an affinity for a polyester resin such as an alkoxyl group, an epoxy group, an amino group, or an amide group. This concentration is preferably 1 to 40 mgKOH / g, more preferably 10 to 35 mgKOH / g, and further preferably 18 to 30 mgKOH / g as the acid value of the polyolefin-based compound.
In addition, an oxidized polyethylene wax is preferable as the polyolefin-based compound since it has a small amount of volatile matter and at the same time has a remarkable effect of improving the releasability.
The acid value can be measured according to a potentiometric titration method (ASTM D1386) using a 0.5 mol KOH ethanol solution.

  Examples of the fatty acid ester compounds include saturated or unsaturated aliphatic monovalent or divalent carboxylic acid esters, glycerin fatty acid esters, sorbitan fatty acid esters and the like, partially saponified products thereof, and the like. Among these, mono- or di-fatty acid esters composed of fatty acids and alcohols having 11 to 28 carbon atoms, preferably 17 to 21 carbon atoms are preferable.

Aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, mellicic acid, tetrariacontanoic acid, montanic acid, adipic acid, azelaic acid Etc. The aliphatic carboxylic acid may be an alicyclic carboxylic acid.
Examples of the alcohol include saturated or unsaturated monovalent or polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, a monovalent or polyvalent saturated alcohol having 30 or less carbon atoms is preferable, and an aliphatic saturated monohydric alcohol or polyhydric alcohol having 30 or less carbon atoms is more preferable. Here, aliphatic includes alicyclic compounds.
Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol, and the like. Is mentioned.
In addition, said ester compound may contain aliphatic carboxylic acid and / or alcohol as an impurity, and may be a mixture of a some compound.

  Specific examples of fatty acid ester compounds include glycerin monostearate, glycerin monopalmitate, glycerin monobehenate, glycerin dibehenate, glycerin-12-hydroxymonostearate, sorbitan monobehenate, pentaerythritol monostearate. , Pentaerythritol distearate, stearyl stearate, ethylene glycol montanate, and the like.

  Moreover, as a silicone type compound, the compound modified | denatured from points, such as compatibility with a polyester resin, is preferable. Examples of the modified silicone oil include silicone oil in which an organic group is introduced into the side chain of polysiloxane, silicone oil in which an organic group is introduced into both ends and / or one end of polysiloxane, and the like. Examples of the organic group to be introduced include an epoxy group, an amino group, a carboxyl group, a carbinol group, a methacryl group, a mercapto group, and a phenol group, and preferably an epoxy group. As the modified silicone oil, a silicone oil in which an epoxy group is introduced into the side chain of polysiloxane is particularly preferable.

However, as described above, the melting point of the release agent (B) needs to be 130 ° C. or less, preferably 120 ° C., more preferably 110 ° C. or less, and further preferably 105 ° C. or less. Although there is no restriction | limiting about the minimum of melting | fusing point of a mold release agent (B), Preferably it is -10 degreeC or more, More preferably, it is 10 degreeC or more, More preferably, it is 30 degreeC or more, Especially preferably, it is 40 degreeC or more.
When the melting point of the release agent (B) exceeds 130 ° C., it becomes difficult for the release agent to precipitate on the surface, the release effect is lowered, and the melting point of the release agent (C) is used in combination. The meaning of the present invention is lost.

[Release agent (C)]
The release agent (C) is a release agent having a melting point of 180 ° C. or higher as measured by a differential scanning calorimeter (DSC). The mold release agent (C) can be used in combination with the mold release agent (B) even in a situation where the mold temperature is difficult to obtain a mold release effect and in a molded product having a complicated shape. (C) works effectively, and an excellent mold release effect can be obtained over the entire molded product. The mold release property can be improved and the cooling time can be shortened compared to the single use of the mold release agent (B). It becomes possible. In particular, when using a mold having a boss, a core pin, or the like that is locally hot and easily stores heat, molding can be performed at a wider range of mold temperatures.

The release agent (C) is not limited as long as the melting point is 180 ° C. or higher, but a high melting point wax or the like is preferable.
Examples of the high melting point wax include carboxylic acid amide waxes, and those composed of a condensate of a higher aliphatic monocarboxylic acid, a polybasic acid and a diamine are particularly preferable.

  The higher aliphatic monocarboxylic acid is preferably a saturated aliphatic monocarboxylic acid having 12 to 22 carbon atoms, and includes lauric acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadecanoic acid, arachidic acid, Behenic acid. It may be a hydroxy group-containing aliphatic monocarboxylic acid. Examples of the hydroxy group-containing aliphatic monocarboxylic acid include 12-hydroxystearic acid. These saturated aliphatic monocarboxylic acids and hydroxy group-containing aliphatic monocarboxylic acids may be used alone or in combination of two or more.

The polybasic acid is preferably a dibasic acid or higher carboxylic acid, more preferably an aliphatic dicarboxylic acid. Examples of the aliphatic dicarboxylic acid include aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutamic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, and 1,10-decanedicarboxylic acid. Examples of the aliphatic dicarboxylic acid include aromatic dicarboxylic acids such as phthalic acid and terephthalic acid, and alicyclic dicarboxylic acids such as cyclohexane dicarboxylic acid and cyclohexyl succinic acid.
These polybasic acids may be used alone or in combination of two or more.

Examples of the diamine include ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, hexamethylenediamine, metaxylenediamine, tolylenediamine, paraxylenediamine, phenylenediamine, isophoronediamine, 1,10-decanediamine, , 12-dodecanediamine, 4,4-diaminodicyclohexylmethane, and 4,4-diaminodiphenylmethane are preferable.
These diamines may be used alone or in combination of two or more.

  A method for producing a high-melting-point wax composed of such components is well known. For example, a saturated aliphatic monocarboxylic acid, a polybasic acid and an aliphatic diamine are heated to 160 to 300 ° C. in the absence of a solvent while heating 2 A dehydration condensation reaction is carried out for 10 hours to condense the aliphatic diamine, the aliphatic monocarboxylic acid and the aliphatic dicarboxylic acid, and a wax having a high melting point is obtained as an amide compound.

The melting point of the release agent (C) is 180 ° C. or higher, preferably 190 ° C., more preferably 200 ° C. or higher. The upper limit of the melting point is not limited, but is usually 300 ° C. or lower, preferably 280 ° C. or lower.
In addition, melting | fusing point of a mold release agent (C) can be calculated | required by the same method as melting | fusing point measurement of a mold release agent (B).

  The acid value of the release agent (C) is preferably 1 to 30 mgKOH / g, more preferably 5 to 25 mgKOH / g, and further preferably 10 to 20 mgKOH / g.

[Contents of Release Agent (B) and Release Agent (C)]
The content ratio of the release agent (B) and the release agent (C) is 3/7 to 8/2 in terms of the mass ratio (B) / (C) of (B) and (C). preferable. When the mass ratio of (B) is less than 3, the mold slipping property when sufficiently cooled decreases, so that the releasability under that condition tends to deteriorate, and when it exceeds 8, the cooling time is short. In some cases, the releasability under high cycle molding conditions tends to deteriorate, which is not preferable. The mass ratio (B) / (C) is more preferably 4/6 to 7/3, and further preferably 5/5 to 6/4.
Moreover, content of a mold release agent (B) and a mold release agent (C) is 0.1-3 mass parts with the sum total of (B) and (C) with respect to 100 mass parts of polyester resins (A). Preferably, it is 0.15 parts by mass or more, more preferably 0.2 parts by mass or more. Moreover, it is more preferable that it is 2.5 mass parts or less, More preferably, it is 2 mass parts or less, Most preferably, it is 1.5 mass parts or less.
If the amount is less than 0.1 parts by mass, the surface property tends to deteriorate due to defective mold release at the time of melt molding. On the other hand, if it exceeds 3 parts by mass, the kneading workability of the resin composition decreases, and molding is also performed. The surface of the product may be cloudy.

[Other ingredients]
The polyester resin composition of the present invention may contain various additives as long as the effects of the present invention are not impaired. Such additives include stabilizers, flame retardants, flame retardant aids, anti-dripping agents, glass fibers, glass flakes, glass beads, carbon fibers, talc, wollastonite, mica and other reinforcing fillers, UV absorption Agents, antistatic agents, antifogging agents, antiblocking agents, plasticizers, dispersants, antibacterial agents, colorants and the like. Further, a lubricant or the like may be externally added for the purpose of improving the measurement stability during the molding process.

<Stabilizer>
It is preferable that the polyester-based resin composition of the present invention contains a stabilizer because it has effects of improving thermal stability and preventing deterioration of mechanical strength, transparency, and hue. As the stabilizer, a phosphorus stabilizer, a sulfur stabilizer and a phenol stabilizer are preferable.

  Examples of the phosphorus-based stabilizer include phosphorous acid, phosphoric acid, phosphite ester, and phosphate ester. Among them, organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds are preferable.

The organic phosphate compound is preferably the following general formula:
(R ¹ O) _3-n P (═O) OH _n
(In the formula, R ¹ is an alkyl group or an aryl group, and may be the same or different. N represents an integer of 0 to 2.)
It is a compound represented by these. More preferably, R ¹ is a long-chain alkyl acid phosphate compound having 8 to 30 carbon atoms. Specific examples of the alkyl group having 8 to 30 carbon atoms include octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, A hexadecyl group, an octadecyl group, an eicosyl group, a triacontyl group, etc. are mentioned.

  Examples of the long-chain alkyl acid phosphate include octyl acid phosphate, 2-ethylhexyl acid phosphate, decyl acid phosphate, lauryl acid phosphate, octadecyl acid phosphate, oleyl acid phosphate, behenyl acid phosphate, phenyl acid phosphate, nonyl phenyl acid phosphate Acid phosphate, phenoxyethyl acid phosphate, alkoxy polyethylene glycol acid phosphate, bisphenol A acid phosphate, dimethyl acid phosphate, diethyl acid phosphate, dipropyl acid phosphate, diisopropyl acid phosphate, dibutyl acid phosphate, geo Chill acid phosphate, di-2-ethylhexyl acid phosphate, dioctyl acid phosphate, dilauryl acid phosphate, distearyl acid phosphate, diphenyl acid phosphate, and a bis-nonylphenyl acid phosphate, or the like. Among these, octadecyl acid phosphate is preferable, and this is marketed under the trade name “ADEKA STAB AX-71” of ADEKA.

As the organic phosphite compound, preferably, the following general formula:
^{R 2 O-P (OR 3} ) (OR 4)
(Wherein R ² , R ³ and R ⁴ are each a hydrogen atom, an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms, and among R ² , R ³ and R ⁴ ) At least one of them is an aryl group having 6 to 30 carbon atoms.)
The compound represented by these is mentioned.

  Examples of the organic phosphite compound include triphenyl phosphite, tris (nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris (2-ethylhexyl) phosphite, and tris (tridecyl). ) Phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono (tridecyl) phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra (tridecyl) pentaerythritol tetraphosphite Hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4′-butylidene-bis (3-methyl-6-t rt-butylphenyldi (tridecyl) phosphite), tetra (tridecyl) 4,4′-isopropylidenediphenyldiphosphite, bis (tridecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, di Lauryl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tris (4-tert-butylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, hydrogenated bisphenol A pentaerythritol phosphite Phytopolymer, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite Phosphite, 2,2'-methylenebis (4,6-di -tert- butylphenyl) octyl phosphite, bis (2,4-dicumylphenyl) pentaerythritol diphosphite and the like. Among these, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite is preferable.

The organic phosphonite compound is preferably the following general formula:
R ⁵ -P (OR ⁶ ) (OR ⁷ )
(In the formula, R ⁵ , R ⁶ and R ⁷ are each a hydrogen atom, an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms, and among R ⁵ , R ⁶ and R ⁷ , At least one of them is an aryl group having 6 to 30 carbon atoms.)
The compound represented by these is mentioned.

  Examples of the organic phosphonite compound include tetrakis (2,4-di-iso-propylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,4-di-n-butylphenyl) -4,4′-biphenyl. Range phosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,4'-biphenylene diphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,3'-biphenylene diphospho Knight, tetrakis (2,4-di-tert-butylphenyl) -3,3'-biphenylenediphosphonite, tetrakis (2,6-di-iso-propylphenyl) -4,4'-biphenylenediphosphonite, Tetrakis (2,6-di-n-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2, -Di-tert-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,3'-biphenylenediphosphonite, and tetrakis (2,6- And di-tert-butylphenyl) -3,3′-biphenylenediphosphonite.

  As the sulfur stabilizer, any conventionally known sulfur atom-containing compound can be used, and among these, thioethers are preferred. Specifically, for example, didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis (3-dodecylthiopropionate), thiobis (N-phenyl-β-naphthylamine) ), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyldithiocarbamate, nickel isopropylxanthate, trilauryltrithiophosphite. Among these, pentaerythritol tetrakis (3-dodecylthiopropionate) is preferable.

  Examples of the phenol-based stabilizer include pentaerythritol tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), octadecyl-3- (3,5-di-tert-butyl-4) -Hydroxyphenyl) propionate, thiodiethylenebis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), pentaerythritol tetrakis (3- (3,5-di-neopentyl-4-hydroxyphenyl) ) Propionate) and the like. Among these, pentaerythritol tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionate is preferred.

  One type of stabilizer may be contained, or two or more types may be contained in any combination and ratio.

  The content of the stabilizer is preferably 0.001 to 1 part by mass with respect to 100 parts by mass of the polyester resin (A). When the content of the stabilizer is less than 0.001 part by mass, it is difficult to expect an improvement in the thermal stability and compatibility of the resin composition, and a decrease in molecular weight and a deterioration in hue during molding are likely to occur. When it exceeds, it will become excess amount and there exists a tendency for generation | occurrence | production of silver and a hue deterioration to occur further easily. The content of the stabilizer is more preferably 0.001 to 0.7 parts by mass, and still more preferably 0.005 to 0.5 parts by mass.

<Other thermoplastic resins>
Moreover, in the polyester-type resin composition of this invention, other thermoplastic resins other than a polyester resin (A) can be contained in the range which does not impair the effect of this invention. Specific examples of the other thermoplastic resins include polycarbonate, polyamide, polyphenylene oxide, polystyrene resin, polyphenylene sulfide ethylene, polysulfone, polyethersulfone, polyetherimide, and polyetherketone.

[Method for Producing Resin Composition]
As a manufacturing method of the polyester-type resin composition of this invention, it can carry out in accordance with the conventional method of resin composition preparation. Usually, the components and various additives added as desired are mixed together and then melt-kneaded in a single-screw or twin-screw extruder. Moreover, it is also possible to prepare the resin composition of the present invention by mixing each component in advance or by mixing only a part of the components in advance and supplying them to an extruder using a feeder and melt-kneading them. Further, a master batch is prepared by melting and kneading a part of the polyester resin (A) and a part of other components, and then the other other ingredients are blended and melt-kneading. Good.
In addition, when using fibrous reinforcement fillers, such as glass fiber, it is also preferable to supply from the side feeder in the middle of the cylinder of an extruder.

  The heating temperature at the time of melt kneading can be appropriately selected from the range of usually 220 to 300 ° C. If the temperature is too high, decomposition gas is likely to be generated, which may cause opacity. Therefore, it is desirable to select a screw configuration in consideration of shear heat generation. In order to suppress decomposition during kneading or molding in the subsequent process, it is desirable to use an antioxidant or a heat stabilizer.

In the polyester resin composition of the present invention, the ratio of the melt viscosity after 60 minutes to the melt viscosity after 3 minutes at a temperature of 270 ° C. and a shear rate of 91.2 sec ⁻¹ (60 min / 3 min) is 2.7 or less. Is preferred. When the ratio of melt viscosity (60 min / 3 min) is larger than 2.7, the thermal stability is lowered, so that resin deterioration is likely to occur, and the obtained molded product may not have desired physical properties. The ratio of melt viscosity (60 min / 3 min) is more preferably 2.65 or less, further preferably 2.6 or less, and the lower limit is preferably 2.5.

[Molded body]
The method for producing a molded body using the polyester-based resin composition of the present invention is not particularly limited, and any molding method generally employed for the polyester resin composition can be arbitrarily employed. For example, injection molding method, ultra-high speed injection molding method, injection compression molding method, two-color molding method, hollow molding method such as gas assist, molding method using heat insulating mold, rapid heating mold were used. Molding method, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding method, extrusion molding method, sheet molding method, thermoforming method, rotational molding method, laminate molding method, press molding method, Examples thereof include a blow molding method. Of these, injection molding is preferred.

  The shape, size, thickness, etc. of the molded body are arbitrary, and its use is suitable for electrical and electronic equipment parts, OA equipment parts, transportation equipment parts such as automobiles, industrial machine parts, and other consumer parts. is there.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not construed as being limited to the following examples.
In the following Examples and Comparative Examples, the components used are as shown in Table 1 below.

(Examples 1-14, Comparative Examples 1-7)
Each component shown in Table 1 was uniformly mixed with a tumbler mixer at the ratio (parts by mass) shown in Tables 2 to 4, and then a twin screw extruder (“TEX30XCT” manufactured by Nippon Steel Works, L / D = 42). ), The resin composition melt-kneaded under conditions of a cylinder set temperature of 270 ° C. and a screw rotation speed of 200 rpm was rapidly cooled in a water tank and pelletized using a pelletizer to obtain a polyester resin composition pellet.

[Evaluation of releasability]
Using the obtained pellet, using a “α100iA type” injection molding machine manufactured by FANUC, with a partition at the center as shown in FIG. 1 at a cylinder temperature of 250 ° C. and a mold temperature controller set temperature of 80 ° C. A side gate (gate thickness of 1. mm) provided with a box-shaped product (vertical 30 mm, width 54 mm, depth 34 mm, wall thickness 1.5 mm) in the vicinity of the front-most center of the left side wall indicated by an arrow of the box-formed product in FIG. 5 mm × gate width 3 mm), resin was injected and molded.

  FIG. 2 is a top view of the box-shaped product and the ejector pin shown in FIG. 1 as viewed from above, and FIG. 3 is an explanatory diagram showing a position where the ejector pin hits the bottom of the box-shaped product. The molded product was extracted by bringing out a total of four ejector pins with pressure sensors shown in FIG. 2 into contact with the bottom plate of the box-shaped product as shown in FIG.

Cooling time starts from 30 seconds, cooling time is gradually shortened to 20 seconds, 10 seconds, 8 seconds, 6 seconds, 5 seconds, 4 seconds, 3 seconds Ejected with an ejector pin and extracted.
Judgment was made based on the following three-stage criteria based on the sound generated when the bottom plate of the resulting box-shaped product was deformed and protruded.
“○: No deformation of the bottom plate and no sound when protruding”
“△: There is deformation of the bottom plate and abnormal noise is generated when protruding.”
“×: There is a break through the bottom plate”
The evaluation results are shown in Tables 2 to 4 below.

  Since the polyester-based resin composition of the present invention is excellent in releasability, various molded products can be produced at a high cycle, and industrial utility is very high.

Claims (4)

Contains a polyester resin (A), the differential scanning calorimeter (DSC) release agent having a melting point of 130 ° C. or below (B) and the releasing agent is a melting point of 180 ° C. or more (C), release agent (B) natural waxes, polyolefin compounds, fatty acid ester-based compound is at least one selected from silicone compounds, polyester-based release agent (C) is characterized amide wax der Rukoto carboxylic acid Resin composition.   The polyester resin composition according to claim 1, wherein the mass ratio (B) / (C) of the contents of the release agent (B) and the release agent (C) is 3/7 to 8/2.   The polyester system according to claim 1 or 2, wherein the content of the release agent (B) and the release agent (C) is 0.1 to 3 parts by mass in total with respect to 100 parts by mass of the polyester resin (A). Resin composition.   The polyester resin composition according to any one of claims 1 to 3, wherein the release agent (B) is an oxidized polyethylene wax.

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