JP2005272827A - Thermoplastic resin composition and its preparation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition which is excellent in hydrolysis resistance and does not cause deterioration of a thermoplastic resin when it is subjected to melt processing at a high temperature after its storage. <P>SOLUTION: The thermoplastic resin composition contains, against 100 pts.wt. thermoplastic resin, (A) 0.001-1 pt.wt. antioxidant of formula (I) (wherein R<SP>1</SP>, R<SP>2</SP>, R<SP>4</SP>and R<SP>5</SP>are each hydrogen, an alkyl, a cycloalkyl, a phenyl or the like; R<SP>3</SP>is hydrogen, an alkyl or the like; X is a single bond or the like; A is an alkylene or the like; one of Y and Z is hydroxy or an aralkyloxy and the other is an alkyl or the like, provided that when Y is a hydroxy, one of R<SP>4</SP>and R<SP>5</SP>is an alkyl and the other is phenyl) and (B) 0.001-150 pts.wt. inorganic anti-blocking agent containing a solid acid in an amount of ≤100 μmol per 1 g of the inorganic anti-blocking agent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermoplastic resin composition containing a thermoplastic resin, an antioxidant and an inorganic antiblocking agent, and a method for producing the same.

  Patent Document 1 describes a thermoplastic resin composition containing a polyethylene resin, an antioxidant having a phosphite structure and a hindered phenol structure in the same molecule, and an inorganic antiblocking agent such as aluminosilicate or kaolin. Has been.

JP 2003-253061 A (refer to paragraph number 0034 and paragraph numbers 0037 to 0050)

Thermoplastic resins are used in a wide range of applications such as films for packaging materials. When processing thermoplastic resins into films for packaging materials, the antioxidant has a phosphite structure and a hindered phenol structure in the same molecule for the purpose of preventing thermal oxidation of the thermoplastic resin during melt kneading at high temperatures. An anti-blocking agent is blended in order to prevent the formed films from adhering to each other (blocking).
However, a thermoplastic resin, an antioxidant having a phosphite structure and a hindered phenol structure in the same molecule (hereinafter sometimes referred to as a hindered phenol type phosphite antioxidant), and a relatively high acid strength. The pellet-shaped thermoplastic resin composition containing an inorganic antiblocking agent having moisture content absorbs moisture while being stored in a warehouse, etc., and the hindered phenol-type phosphite antioxidant is hydrolyzed, and the thermoplastic after the storage is finished. There was a problem that the antioxidant performance of the resin composition was lowered, and the thermoplastic resin was deteriorated when the film was melt processed at a high temperature.

  As a result of intensive investigations to provide a thermoplastic resin composition that is excellent in hydrolysis resistance and that does not deteriorate the thermoplastic resin when melt-processed at a high temperature even after completion of storage in a warehouse or the like, a solid When an inorganic antiblocking agent having an acid amount of 100 μmol or less per gram and a specific antioxidant are blended in the thermoplastic resin, hydrolysis resistance of the hindered phenol-type phosphite antioxidant in the obtained resin composition The present invention was completed by discovering that the thermoplastic resin could be prevented from being deteriorated when melted at a high temperature after being stored in a warehouse or the like and then melt processed at a high temperature.

That is, this invention contains 0.001-1 weight part of following (A), and 0.001-150 weight part of following (B) per 100 weight part of thermoplastic resins and this thermoplastic resin. The present invention provides a thermoplastic resin composition (not including a hindered amine light stabilizer).
(A) Antioxidant (B) represented by the following formula (I) Inorganic antiblocking agent having a solid acid amount of 100 μmol or less per 1 g

（Ｉ）
［式中、Ｒ^１、Ｒ^２、Ｒ^４及びＲ^５は、それぞれ独立に水素原子、炭素数１〜８のアルキル基、炭素数５〜８のシクロアルキル基、炭素数６〜１２のアルキルシクロアルキル基、炭素数７〜１２のアラルキル基又はフェニル基を表し、Ｒ^３は水素原子又は炭素数１〜８のアルキル基を表す。Ｘは単結合、硫黄原子又は−ＣＨＲ⁶−基を表す。Ｒ⁶は水素原子、炭素数１〜８のアルキル基又は炭素数５〜８のシクロアルキル基を表す。
Ａは炭素数２〜８のアルキレン基又は＊−ＣＯＲ⁷−基を表し、Ｒ⁷は単結合又は炭素数１〜８のアルキレン基を表し、＊印を付した−ＣＯＲ⁷−基は式（Ｉ）におけるフォスファイト構造の酸素原子と結合していることを表す。
Ｙ及びＺは、いずれか一方がヒドロキシル基、炭素数１〜８のアルコキシ基又は炭素数７〜１２のアラルキルオキシ基を表し、他方が水素原子又は炭素数１〜８のアルキル基を表す。
但し、Ｙがヒドロキシル基であるときは、Ｒ^４及びＲ^５の一方は炭素数３〜８のアルキル基、炭素数５〜８のシクロアルキル基、炭素数６〜１２のアルキルシクロアルキル基、炭素数７〜１２のアラルキル基又はフェニル基を表す。
また、式（Ｉ）における２個のＲ^１は互いに同一でもよく、異なってもよい。さらに、式（Ｉ）における２個のＲ^２は互いに同一でもよく、異なってもよい。そして、式（Ｉ）における２個のＲ^３は互いに同一でもよく、異なってもよい。］

(I)
[Wherein R ¹ , R ² , R ⁴ and R ⁵ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, or an alkylcyclohexane having 6 to 12 carbon atoms. An alkyl group, an aralkyl group having 7 to 12 carbon atoms, or a phenyl group is represented, and R ³ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. X represents a single bond, a sulfur atom or a —CHR ⁶ — group. R ⁶ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms.
A represents an alkylene group having 2 to 8 carbon atoms or * —COR ⁷ — group, R ⁷ represents a single bond or an alkylene group having 1 to 8 carbon atoms, and —COR ⁷ — group marked with * is represented by the formula ( It represents that it is bonded to the oxygen atom of the phosphite structure in I).
One of Y and Z represents a hydroxyl group, an alkoxy group having 1 to 8 carbon atoms or an aralkyloxy group having 7 to 12 carbon atoms, and the other represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.
However, when Y is a hydroxyl group, one of R ⁴ and R ⁵ is an alkyl group having 3 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an alkylcycloalkyl group having 6 to 12 carbon atoms, carbon It represents an aralkyl group or a phenyl group of formula 7-12.
Moreover, two R < ¹ > in Formula (I) may mutually be same, and may differ. Furthermore, two R ² in the formula (I) may be the same or different. And two R < ³ > in Formula (I) may mutually be same, and may differ. ]

  In the present invention, 0.001 to 1 part by weight of the above (A) and 0.001 to 150 parts by weight of the above (B) are blended per 100 parts by weight of the thermoplastic resin. And a hindered amine light stabilizer), and a method for producing a thermoplastic resin composition characterized by melt-kneading.

  According to the thermoplastic resin composition of the present invention, the hydrolysis resistance of the hindered phenol-type phosphite antioxidant is improved, and the product is stored in a warehouse for a long time after the thermoplastic resin composition is produced. However, the antioxidant performance of the thermoplastic resin composition is not impaired. Moreover, according to the manufacturing method of the thermoplastic resin composition of the present invention, a thermoplastic resin composition that does not impair the antioxidant performance even when stored in a warehouse for a long time can be obtained.

Hereinafter, the present invention will be described in detail.
Examples of the thermoplastic resin used in the present invention include the following.
(1) Polyethylene, for example, high density polyethylene (HD-PE), low density polyethylene (LD-PE), linear low density polyethylene (LLDPE), (2) polypropylene, (3) methylpentene polymer, (4) EEA (Ethylene / ethyl acrylate copolymer) resin, (5) ethylene / vinyl acetate copolymer resin, (6) polystyrenes such as polystyrene, poly (p-methylstyrene) and poly (α-methylstyrene), (7) AS (acrylonitrile / styrene copolymer) resin, (8) ABS (acrylonitrile / butadiene / styrene copolymer) resin, (9) AAS (special acrylic rubber / acrylonitrile / styrene copolymer) resin, (10) ACS (acrylonitrile / chlorine) Polyethylene / styrene copolymer) resin,

(11) Chlorinated polyethylene, polychloroprene and chlorinated rubber, (12) polyvinyl chloride and polyvinylidene chloride, (13) methacrylic resin, (14) ethylene / vinyl alcohol copolymer resin, (15) fluororesin, (16 ) Polyacetal, (17) grafted polyphenylene ether resin and polyphenylene sulfide resin, (18) polyurethane, (19) polyamide, (20) polyester resin such as polyethylene terephthalate and polybutylene terephthalate, (21) polycarbonate, (22) poly Acrylate, (23) polysulfone, polyetheretherketone and polyethersulfone, (24) aromatic polyester resin, (25) diallyl phthalate prepolymer, (26) silicone resin, (27) 1,2-poly Butadiene, (28) polyisoprene, (29) styrene / butadiene copolymer, (30) butadiene / acrylonitrile copolymer, (31) ethylene / propylene copolymer, (32) ethylene / MMA (methyl methacrylate) copolymer Coalescence.

As the thermoplastic resin in the present invention, one or a mixture of the above-exemplified resins can be used.
In the present invention, polyolefins such as polyethylene (eg HD-PE, LD-PE, LLDPE) and polypropylene; copolymers such as ethylene and vinyl acetate; copolymers such as ethylene and MMA; polyamides, polyethylene terephthalate, polybutylene Engineering resins such as terephthalate and polycarbonate, polystyrene (GP-PS, HI-PS), binary copolymers or terpolymers of styrene and isoprene or butadiene) are preferably used. Furthermore, a polymer such as polyethylene or polypropylene, a polyolefin resin such as a copolymer of ethylene and vinyl acetate or the above MMA, or a styrene resin obtained by using polystyrene or styrene as a raw material monomer is preferable. Among these resins, polyolefin resins are particularly preferable.

The method for producing the polyolefin is not particularly limited. For example, it may be obtained by radical polymerization, and a catalyst containing a metal of Group IVb, Group Vb, Group VIb or Group VIII of the periodic table is used. It may be produced by polymerization.
The metal-containing catalyst may be a metal complex having one or more ligands, for example, an oxide coordinated by a π bond or a σ bond, a halogen compound, an alcoholate, an ester, an aryl, These complexes may be used as they are or may be supported on a base material such as magnesium chloride, titanium chloride, alumina, or silicon oxide.
As polyolefin, what was manufactured, for example using a Ziegler Natta catalyst, a metallocene catalyst, a Phillips catalyst, etc. is used preferably.

Also, the engineering resin is not particularly limited. For example, any polyamide resin may be used as long as it has an amide bond in the polymer chain and can be melted by heating. The production method of the polyamide resin is not limited, and may be produced by a method such as a condensation reaction of diamines and dicarboxylic acids, a condensation reaction of aminocarboxylic acids, or ring-opening polymerization of lactams.
Typical examples of the polyamide resin include nylon 66, nylon 69, nylon 610, nylon 612, poly-bis (p-aminocyclohexyl) methane dodecamide, nylon 46, nylon 6, nylon 12, nylon 66 and nylon 6 Examples include nylon 66/6, which is a coalescence, and a copolymer such as nylon 6/12.
Any polyester resin may be used as long as it has an ester bond in the polymer chain and can be melted by heating.
Specific examples of the polyester resin include homopolyesters and copolyesters obtained by polycondensation of dicarboxylic acids and dihydroxy compounds.
Any polycarbonate resin may be used as long as it has a carbonate bond in the polymer chain and can be melted by heating.
Examples of such polycarbonate resins include phosgene and diphenyl carbonate in the presence or absence of a small amount of a polyhydroxy compound in the presence or absence of a solvent, an acid acceptor or a molecular weight modifier. The polycarbonate obtained by making a carbonate precursor react is mentioned.
The polycarbonate resin may be linear or branched, and may be a copolymer.

In the present invention, a hindered phenol type phosphite antioxidant (I) is used. Among the antioxidants, preferred compounds are exemplified below.
6- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetra-t-butyldibenz [d, f] [1,3,2] di Oxaphosphepine [hereinafter referred to as A-2], 6- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propoxy] -2,4,8,10-tetra-t-butyldibenz [d, f] [1,3,2] dioxaphosphine, 6- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propoxy] -4,8-di-t- Butyl-2,10-dimethyl-12H-dibenzo [d, g] [1,3,2] dioxaphosphocin or 6- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl Oxy] -4,8-di-t-butyl-2,10-dimethyl-12H-dibenzo [d, g] [1,3,2] Okisahosuhoshin like.

In producing the thermoplastic resin composition of the present invention, 0.001 to 1 part by weight of one or more of the hindered phenol type phosphite antioxidant (I) is contained per 100 parts by weight of the thermoplastic resin. The content of the antioxidant is more preferably 0.01 to 0.5 parts by weight, and particularly preferably 0.05 to 0.2 parts by weight.
A composition in which the content of the hindered phenol type phosphite antioxidant (I) is less than 0.001 part by weight per 100 parts by weight of the thermoplastic resin does not provide sufficient antioxidant performance during melt-kneading. . On the other hand, since the antioxidant performance does not change even if it exceeds 1 part by weight of the antioxidant per 100 parts by weight of the thermoplastic resin, it is economically disadvantageous.
In the production method of the present invention, the method of mixing the hindered phenol type phosphite antioxidant (I) is not particularly limited, but the method of directly mixing the antioxidant (I) and the thermoplastic resin, the oxidation described above in advance. A method of mixing a masterbatch containing a high concentration of the inhibitor (I) with the above-mentioned thermoplastic resin or kneading and mixing the heated and melted antioxidant (I) directly with the thermoplastic resin through the side feeder of the extruder. A method or the like is preferable.

The inorganic antiblocking agent in the present invention is not particularly limited as long as the solid acid amount is 100 μmol or less per gram, but an inorganic antiblocking agent having an average particle size of 0.1 to 30 μm is preferable.
Examples of inorganic antiblocking agents include silica, clay, diatomaceous earth, feldspar, talc, zeolite, kaolinite, wollastonite, sericite, aluminosilicate, calcium silicate, sodium aluminosilicate, sodium calcium aluminosilicate, hydrotalcite, and the like. Examples thereof include calcium carbonate.

The solid acid amount of the inorganic antiblocking agent is calculated according to the method described in “Resin for Pigment Dispersion Medium” (Toshikatsu Kobayashi, etc.) in “Coloring Materials, 61 [12] 692-698 (1988)”, for example. Use the value obtained.
Specifically, 2 g of the above-mentioned inorganic antiblocking agent was placed in a centrifugal sedimentation tube, 30 ml of 0.01 N diethanolamine methylisobutylketone solution was added and ultrasonic dispersion was performed for 1 hour, and the resulting solution was centrifuged at 13000 rpm for 30 minutes. 10 ml of the obtained supernatant was collected, and the collected supernatant was diluted with 100 ml of methyl isobutyl ketone, and back-titration was performed with a methyl isobutyl ketone solution of 0.01N perchloric acid to obtain the inorganic antiblocking agent. The solid acid amount (μmol) per gram is calculated.
Of the inorganic antiblocking agents used in the present invention, those having a solid acid amount per gram of 50 μmol or less are particularly preferred. When an inorganic antiblocking agent having a solid acid amount per gram exceeding 100 μmol is used, the hydrolysis resistance of the hindered phenol type phosphite antioxidant (I) in the thermoplastic resin composition is lowered.

As the inorganic antiblocking agent in the present invention, one or two or more of the above solid acid amounts of 100 μmol or less per 1 g can be used. The amount of the inorganic antiblocking agent used is preferably in the range of 0.01 to 100 parts by weight, particularly preferably in the range of 0.05 to 20 parts by weight, per 100 parts by weight of the thermoplastic resin.
When the amount of the inorganic anti-blocking agent used is less than 0.001 part by weight per 100 parts by weight of the thermoplastic resin, the anti-blocking effect when the thermoplastic resin composition is formed into a film is not sufficient. On the other hand, even if the amount of the inorganic antiblocking agent used exceeds 150 parts by weight per 100 parts by weight of the thermoplastic resin, an improvement in the antiblocking effect commensurate with the amount used is not recognized.
In the present invention, the method of mixing the inorganic anti-blocking agent is not particularly limited, but the method of mixing the anti-blocking agent with the thermoplastic resin as it is or the master batch in which the inorganic anti-blocking agent is blended at a high concentration in advance into the thermoplastic resin. A method of mixing is preferable.

In the present invention, in addition to the above thermoplastic resin, hindered phenol type phosphite antioxidant (I) and inorganic antiblocking agent, if necessary, other than one or more of the above antioxidants (I) A phenolic antioxidant, a phosphorus antioxidant, a lubricant, a neutralizing agent, an antistatic agent, an inorganic filler and a pigment can also be blended.
Phenolic antioxidants, phosphorus antioxidants, lubricants, neutralizing agents, antistatic agents and pigments other than the antioxidant (I) that can be used in the present invention are not particularly limited. A compound such as
<Phenolic antioxidants other than antioxidant (I) or phosphorus antioxidants>
2,6-di-tert-butyl-4-methylphenol, n-octadecyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, pentaerythrityl tetrakis (3- (3,5- Di-t-butyl-4-hydroxyphenyl) propionate), triethylene glycol bis (3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate), 1,3,5-trimethyl-2, 4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, 3,9-bis (2- (3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy) -1,1-dimethylethyl) -2,4,8,10-tetra Oxaspiro [5 · 5] undecane, 2,2′-methylenebis (6-tert-butyl-4-methylphenol), 4,4′-butylidenebis (6-tert-butyl-3-methylphenol), 4,4 ′ -Thiobis (6-t-butyl-3-methylphenol), 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate and 2- (1 -(2-hydroxy-3,5-t-amylphenyl) ethyl) -4,6-di-t-amylphenyl acrylate and the like;

  Bis (2,4-di-t-butylphenyl) pentaerythrityl diphosphite, tetrakis (2,4-di-butylphenyl) -4,4′-biphenylene-diphosphonite, bis (2,6 -Di-t-butyl-4-methylphenyl) pentaerythrityl diphosphite, bis (2,4-di-t-butyl-6-methylphenyl) ethyl phosphite, tetrakis (2,4-di-butyl- 5-methylphenyl) -4,4′-biphenylene-diphosphonite, bis (2,4-dicumylphenyl) pentaerythrityl diphosphite, 2,4,8,10-tetra-t-butyl- 6- (2-Ethylhexyloxy) -12H-dibenzo [d, g] [1,3,2] dioxaphosphocin, tris (2,4-di-t-butylphenyl Phosphite (hereinafter, referred to as A-1) and tris (mono- or di-nonylphenyl) phosphite or the like;

<Neutralizing agent>
Calcium stearate, calcium hydroxide, etc .;
<Lubricant>
Erucic acid amide, stearic acid amide, oleic acid amide, behenic acid amide, N-stearyl butyric acid amide, N-stearyl lauric acid amide, N-stearyl stearic acid amide, N-stearyl behenic acid amide, N-oleyl oleic acid Amides, N-oleyl behenic acid amides, N-butylerucic acid amides, N-octylerucic acid amides, N-laurylerucic acid amides, ethylenebisstearic acid amides, ethylenebisoleic acid amides, hexamethylenebisoleic acid amides, N, N '-Dioleoyl adipic acid amide, N, N'-dioleyl sebacic acid amide, paraffin, polyethylene wax, stearic acid, butyl stearate, stearyl alcohol and hydrogenated castor oil;

<Antistatic agent>
Cationic antistatic agents such as primary amine salts, tertiary amine salts, quaternary amine salts and pyridine derivatives,
Sulfated oil, soap, sulfated ester oil, sulfated amide oil, sulfated olefin salt of olefin, fatty alcohol sulfate, alkyl sulfate, fatty acid ethyl sulfonate, alkyl naphthalene sulfonate, alkyl benzene sulfonate Anionic antistatic agents such as oxalate sulfonates and phosphate esters,
Partial fatty acid ester of polyhydric alcohol, ethylene oxide adduct of fatty alcohol, ethylene oxide adduct of fatty acid, ethylene oxide adduct of fatty amino or fatty acid amide, ethylene oxide adduct of alkylphenol, partial fatty acid ester of polyhydric alcohol Nonionic antistatic agents such as ethylene oxide adducts and polyethylene glycol,
Amphoteric antistatic agents such as carboxylic acid derivatives and imidazoline derivatives;
<Pigment>
Carbon black, titanium oxide, dial, phthalocyanine pigment, azo pigment, etc .;

  Furthermore, the blending amount of phenolic antioxidant, phosphorus antioxidant, lubricant, neutralizing agent, antistatic agent and pigment other than the antioxidant (I) that can be used in the present invention is 100 parts by weight of thermoplastic resin. It is preferable to use in the range of 0.001 to 10 parts by weight.

  Further, in the present invention, the thermoplastic resin includes one or more phenolic antioxidants other than the antioxidant (I), the inorganic antiblocking agent, and the antioxidant (I), a phosphorus antioxidant, A neutralizer, a lubricant, an antistatic agent and a pigment may be blended, but it is desirable not to blend a hindered amine light stabilizer. When the hindered amine light stabilizer is blended with the thermoplastic resin, the degree of coloring in the thermoplastic resin due to the influence of NOx gas, heating, wet heat, heat, combustion gas, etc. during storage in the warehouse may be hindered amine light stabilizer. It may increase compared with the case where it is not blended.

In the present invention, the apparatus used for the production of the thermoplastic resin composition is not particularly limited. Examples of the apparatus include a mixer such as a tumbler blender, a Henschel mixer or a super mixer, a single-screw or multi-screw extruder, a kneader, a Banbury mixer, and the like.
The thermoplastic resin composition comprises a thermoplastic resin, an antioxidant (I), an inorganic antiblocking agent having a solid acid amount of 100 μmol or less per gram, and the antioxidant (I) used as necessary. Non-phenolic antioxidants, phosphorus antioxidants, lubricants, neutralizing agents, antistatic agents and pigments are mixed uniformly in advance with a mixer such as a tumbler blender, Henschel mixer or super mixer, and then uniaxial Examples thereof include a method of melt-kneading and granulating with an extruder or a multiaxial extruder, or a method of granulating with an extruder after melt-kneading with a kneader or a Banbury mixer.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited by these examples.

[Inorganic anti-blocking agent used in each example]
B-1: “Silton JC-30” (sodium calcium aluminosilicate) manufactured by Mizusawa Chemical Co., Ltd.
B-2: “Silton AMT-30” (sodium aluminosilicate) manufactured by Mizusawa Chemical Co., Ltd.
B-3: “Insulite MC-6” (aluminosilicate) manufactured by Mizusawa Chemical Co., Ltd.
B-4: “Dikalite WF” (diatomaceous earth) manufactured by Grefco Co., Ltd.
B-5: “Mizukasil P-707” (synthetic silica) manufactured by Mizusawa Chemical Co., Ltd.

[Preparation of Resin Composition of Example 1]
In 100 parts by weight of unstabilized polyethylene powder, 0.2 part by weight of antioxidant A-2 according to paragraph 0015, 0.1 part by weight of B-1 above, and 0.1 part by weight of calcium stearate After blending, the mixture was granulated using a single screw extruder to obtain pellets.

[Measurement example 1 of solid acid amount of inorganic antiblocking agent]
2 g of the above B-1 was placed in a centrifugal sedimentation tube, and 30 ml of a 0.01 N diethanolamine methyl isobutyl ketone solution was added, followed by ultrasonic dispersion for 1 hour. The liquid obtained after ultrasonic dispersion was centrifuged at 13000 rpm for 30 minutes, and 10 ml of the obtained supernatant was collected.
The collected supernatant was diluted with 100 ml of methyl isobutyl ketone. This diluted solution was back titrated with 0.01N perchloric acid in methyl isobutyl ketone to calculate the amount of solid acid (μmol) per gram of Sample B-1.

[Measurement example 2 of solid acid amount of inorganic antiblocking agent]
1 g of the above B-5 was placed in a centrifugal settling tube, 50 ml of a methyl isobutyl ketone solution of 0.02N diethanolamine was added, and ultrasonic dispersion was performed for 1 hour. The liquid obtained after ultrasonic dispersion was centrifuged at 13000 rpm for 30 minutes, and 10 ml of the obtained supernatant was collected. The collected supernatant was diluted with 100 ml of methyl isobutyl ketone. This diluted solution was subjected to back titration with a methyl isobutyl ketone solution of 0.01N perchloric acid to calculate the amount of solid acid (μmol) per 1 g of Sample B-5.

[Storage stability test]
The pellets obtained in the preparation examples of the thermoplastic resin composition were stored at 50 ° C. and 80% relative humidity. After storage, the liquid containing the antioxidant obtained by Soxhlet extraction was analyzed by gas chromatography or liquid chromatography to determine the content of the antioxidant in the pellets. The content after the end of storage when the content of the antioxidant in the pellet at the start of storage was set to 100 was expressed as a residual rate (%).

[Antioxidation performance of the thermoplastic resin composition after storage]
The pellets obtained in the preparation examples of the thermoplastic resin composition were stored at 50 ° C. and 80% relative humidity. The time until the heat generation of the resin started was measured using DSC (differential scanning calorimeter) in the air atmosphere of the thermoplastic resin composition after storage. The longer the time until the heat generation of the resin starts, the better the antioxidant performance.

Examples 1-9 and Comparative Examples 1-3
In Examples 2 to 8 and Comparative Examples 1 to 3, pellets were produced according to the preparation of the resin composition of Example 1. In Example 9, pellets were produced according to the preparation of the resin composition of Example 1 except that 0.3 parts by weight of calcium stearate was added. Furthermore, Example 10 produced pellets according to the preparation of the resin composition of Example 1 except that 0.3 parts by weight of calcium hydroxide was added. And the solid acid amount in the inorganic antiblocking agent used in the Example was measured according to the measurement example 1 of the said solid acid amount. The amount of solid acid per gram of the inorganic antiblocking agent used in Comparative Examples 1 and 2 was measured according to Measurement Example 2 for measuring the amount of solid acid.

The thermoplastic resin composition obtained by this invention is used for uses, such as a film for packaging materials, for example.

Claims (6)

Heat comprising the thermoplastic resin, 0.001-1 parts by weight of the following (A), and 0.001-150 parts by weight of the following (B) per 100 parts by weight of the thermoplastic resin Plastic resin composition (however, hindered amine light stabilizer is not included).
(A) Antioxidant represented by the following formula (I) (B) Inorganic antiblocking agent having a solid acid amount of 100 μmol or less per 1 g

(I)
[Wherein R ¹ , R ² , R ⁴ and R ⁵ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, or an alkylcyclohexane having 6 to 12 carbon atoms. An alkyl group, an aralkyl group having 7 to 12 carbon atoms, or a phenyl group is represented, and R ³ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. X represents a single bond, a sulfur atom or a —CHR ⁶ — group. R ⁶ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms.
A is an alkylene group or a * -COR ⁷ 2 to 8 carbon atoms - group. R ⁷ represents a single bond or an alkylene group having 1 to 8 carbon atoms, and the —COR ⁷ — group marked with * represents that it is bonded to the oxygen atom of the phosphite structure in formula (I).
One of Y and Z represents a hydroxyl group, an alkoxy group having 1 to 8 carbon atoms or an aralkyloxy group having 7 to 12 carbon atoms, and the other represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.
However, when Y is a hydroxyl group, one of R ⁴ and R ⁵ is an alkyl group having 3 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an alkylcycloalkyl group having 6 to 12 carbon atoms, carbon It represents an aralkyl group or a phenyl group of formula 7-12.
Moreover, two R < ¹ > in Formula (I) may mutually be same, and may differ. Furthermore, two R ² in the formula (I) may be the same or different. And two R < ³ > in Formula (I) may mutually be same, and may differ. ] Furthermore, the thermoplastic resin composition of Claim 1 containing the following (C).
(C) One or more additives selected from the group consisting of phenolic antioxidants, phosphorus antioxidants, lubricants, neutralizing agents, antistatic agents, and pigments   The thermoplastic resin composition according to claim 1 or 2, wherein the thermoplastic resin is a polyolefin resin or a polystyrene resin.   A thermoplastic resin and 0.001 to 1 part by weight of (A) according to claim 1 and 0.001 to 150 parts by weight of (B) are blended per 100 parts by weight of the thermoplastic resin (however, a hindered amine type) A process for producing a thermoplastic resin composition, which does not contain a light stabilizer and is melt-kneaded.   Furthermore, the manufacturing method of the thermoplastic resin composition of Claim 4 which mix | blends (C) of Claim 2. The method for producing a thermoplastic resin composition according to claim 4 or 5, wherein the thermoplastic resin is a polyolefin resin or a polystyrene resin.