JPH07324155A - Polyacetal resin composition - Google Patents

Abstract

PURPOSE:To provide a polyacetal resin composition excellent in thermal aging resistance and heat stability and reduced in mold deposit and aging discoloration. CONSTITUTION:This composition is prepared by adding 0.01-1 pt.wt. calcium aliphatic carboxylate having a calcium ion content of 1-50ppm and a chloride ion content of 10-100ppm to 100 pts.wt. polyacetal resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention provides a polyacetal resin by adding an aliphatic carboxylic acid calcium salt having a calcium ion content of 1 to 50 ppm and a chlorine ion content of 10 to 100 ppm to the polyacetal resin. The present invention relates to improving heat aging resistance, aging discoloration property, heat stability and mold deposit property.

[0002]

2. Description of the Related Art Polyacetal resins have a good balance of mechanical properties, chemical resistance, and slidability and are easy to process. Widely used mainly for mechanical parts. When using polyacetal resin for automobile parts, heat aging resistance is an essential property. As a method of improving the heat aging resistance of the polyacetal resin, a method of adding an alkaline earth metal salt of an aliphatic carboxylic acid to the polyacetal resin is generally known. (Japanese Patent Publication 55-2250
No. 8, Japanese Patent Publication No. 60-56748)

[0003]

However, when an alkaline earth metal salt of an aliphatic carboxylic acid is added to a polyacetal resin, the heat aging resistance is improved but the aging discoloration is poor, and the heat stability during molding is improved. Also, the mold deposit property is poor. Therefore, the appearance of the product is impaired,
Further, there is a problem that the molding work environment is deteriorated, and there is a strong demand for improvement.

[0004]

Means for Solving the Problems As a result of extensive studies to solve the above problems, the present invention found a polyacetal resin composition excellent in heat aging resistance, heat stability and mold deposit property, and having good aging discoloration property. It was
In order to improve the heat aging resistance, aging discoloration property, thermal stability and mold deposit property of the polyacetal resin, an aliphatic carboxylic acid having a calcium ion content of 1 to 50 ppm and a chlorine ion content of 10 to 100 ppm. It was found that an excellent effect can be obtained by adding a calcium salt, and the present invention has been reached.

That is, the present invention is based on the polyacetal resin 100.
Calcium ion content is 1 to 50 pp with respect to parts by weight
m, and the chlorine ion content is 10 to 100 pp
It is a polyacetal resin composition obtained by adding 0.01 to 1 part by weight of the aliphatic carboxylic acid calcium salt of m. Calcium ion content of polyacetal resin is 1-50p
pm and the chlorine ion content is 10 to 100p
The polyacetal resin composition obtained by adding the aliphatic carboxylic acid calcium salt of pm has a higher thermal stability, mold deposit property, and aging discoloration than the polyacetal resin composition containing the aliphatic calcium carboxylate outside the above range. Is remarkably excellent. If either the calcium ion content or the chlorine ion content exceeds the content referred to in the present invention, it cannot have both the aging discoloration property, the thermal stability and the mold deposit property. For example, even if the calcium ion content is 1 to 50 ppm, a polyacetal composition to which an aliphatic carboxylic acid calcium salt having a chlorine ion content of more than 100 ppm is added has poor thermal stability and poor mold depositability. . Further, when the chlorine ion content is 10 ppm or less, the mold deposit property deteriorates. On the other hand, when the calcium ion content exceeds 50 ppm even if the chlorine ion content is 10 to 100 ppm, the aging discoloration property is not improved and the mold deposit property is also poor. 1ppm again
When it is less than 1, the heat aging resistance is deteriorated. This fact solves the problem of poor appearance of the molded product, which is a problem when the polyacetal resin composition is used in a high temperature atmosphere, and also significantly improves the molding work environment.
Further, the composition of the present invention is also excellent in heat-resistant aging property, and is therefore suitable as a material for mechanical parts around an automobile engine.

The present invention will be described in detail below. The polyacetal resin of the present invention refers to an oxymethylene homo-substantially composed of oxymethylene units, which is produced from a formaldehyde monomer or a cyclic oligomer such as a trimer (trioxane) or a tetramer (tetraoxane) thereof. Polymers and the above raw materials and sterically hindered hindered phenolic antioxidants such as ethylene oxide, propylene oxide, epichlorohydrin, 1,3-dioxolane, 1,4-butanediol, glycol formal and diglycol formal added in an amount of 10 to 500 ppm. An oxymethylene copolymer containing 0.1 to 20% by weight of an oxyalkylene unit having 2 to 8 carbon atoms, which is produced from a cyclic formal. Above all, the amount of formaldehyde gas generated when heated at 230 ° C. for 60 minutes under a nitrogen stream is 500 ppm or less, and more preferably 300 ppm or less. Also included are oxymethylene copolymers having branched molecular chains and oxymethylene block copolymers containing less than 50% by weight of different polymer units containing 50% by weight or more of oxymethylene repeating units.

The method for producing the polyacetal resin is not particularly limited, and it can be produced by a conventionally known method. For example, formaldehyde or trioxane cyclic ether, obtained by copolymerization with cyclic formal, subjected to a stabilization treatment of the molecular ends immediately after the polymerization, then injecting a hydroxyl group-containing compound or a mixture thereof in a molten state, and then kneading, And continuously supplying and treating by a counter-rotating non-intermeshing twin-screw extruder or the like comprising at least two steps having a degassing step for releasing the injected vapor of the hydroxyl group-containing compound and free formaldehyde, By removing volatile components from the molten polyacetal, the amount of formaldehyde gas generated when heated under a nitrogen stream at 230 ° C for 60 minutes was 5
A polyacetal resin of less than 00 ppm is obtained. When injecting the above-mentioned hydroxyl group-containing compound or a mixture thereof and then kneading, it is preferable to add a basic substance such as triethylamine as a pH adjusting agent. A sterically hindered hindered phenolic antioxidant may be added during the polyacetal polymerization or before the unstable terminal treatment.

As the aliphatic carboxylic acid calcium salt,
It is a calcium salt of a saturated or unsaturated aliphatic carboxylic acid having 10 to 36 carbon atoms. These carboxylic acids may be substituted with hydroxyl groups. As the saturated aliphatic carboxylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid,
Examples thereof include behenic acid, lignoceric acid, cerotic acid, montanic acid, melissic acid, and ceroplastic acid. Unsaturated aliphatic carboxylic acids include undecylenic acid, oleic acid,
Examples thereof include elaidic acid, cetoleic acid, erucic acid, brassic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid, propiolic acid and stearolic acid. Among these aliphatic carboxylic acids, lauric acid, stearic acid and behenic acid are particularly preferable.

The method for producing the calcium salt of an aliphatic carboxylic acid is not particularly limited, and the calcium ion content is substantially 1 to 50 ppm, and the chloride ion content is 10 to 100 ppm. Any method of producing a salt may be used. For example, in the case of producing an aliphatic calcium carboxylate by the reaction of an aliphatic sodium carboxylate and calcium chloride, the number of washing with water is increased, and the calcium ion is washed with 1 to 50 ppm and chlorine ion to 10 to 100 ppm,
Just remove it. Also in the case of producing an aliphatic calcium carboxylate by the reaction of an aliphatic carboxylic acid and calcium hydroxide, the number of times of washing with water is increased in the same manner as above, and the washing with water is repeated until the calcium ion becomes 1 to 50 ppm and the chlorine ion becomes 10 to 100 ppm. , It should be removed. Alternatively, calcium hydroxide having a low chlorine ion content may be used.

The calcium ion content in the aliphatic carboxylic acid calcium salt can be quantified by ion chromatography. For example, an aliphatic carboxylic acid calcium salt is added to a methanol / water mixed solution and sonicated. The filtrate filtered with the back paper is quantified by ion chromatography. The method for quantifying the chlorine ion content is also quantified by the same ion chromatography as the method for quantifying the calcium ion content.

The calcium ion content and the chloride ion content in the aliphatic carboxylic acid calcium salt were quantified by the above method, and the calcium ion content was 1 to 50 ppm.
In addition, the polyacetal resin to which the calcium salt of aliphatic carboxylic acid having a chlorine ion content of 10 to 100 ppm is added has excellent heat aging resistance, aging discoloration property, heat stability, and mold deposit property. More preferably, the calcium ion content is 1 to 30 ppm and the chloride ion content is 10 to 60 ppm. Calcium ion content of aliphatic carboxylic acid calcium salt is 50p
When the content is more than pm, the aging discoloration of the polyacetal resin composition containing the calcium salt of an aliphatic carboxylic acid is remarkably poor, the appearance of the molded product is deteriorated, and the mold deposit property is also poor. Further, if it is less than 1 ppm, there is a problem in heat aging resistance. When the chlorine ion content is more than 100 ppm, the polyacetal resin composition containing the calcium salt of an aliphatic carboxylic acid has poor thermal stability and mold deposit properties, and when it is less than 10 ppm, the mold deposit is less than 100 ppm. The sex becomes worse.

The calcium ion content is 1 to 50 p
pm, and the chlorine ion content is 10 to 100 ppm
The addition amount of the aliphatic carboxylic acid calcium salt is 0.01 to 1 part by weight with respect to 100 parts by weight of the polyacetal resin. It is preferably 0.01 to 0.5 parts by weight. It is more preferably 0.01 to 0.3 parts by weight. When the amount of the aliphatic carboxylic acid calcium salt added is less than 0.01 parts by weight, the heat aging resistance is poor, and when the amount added is more than 1 part by weight, discoloration after aging is severe and heat resistance is high. Poor stability and mold deposit.

As the other stabilizer that can be used in the present invention, any stabilizer that is usually used in polyacetal resins can be used without any limitation, and various known stabilizers can be added. Examples thereof include polymers containing formaldehyde-reactive nitrogen, hindered phenolic antioxidants, fatty acid ester compounds and the like.

Polymers containing formaldehyde-reactive nitrogen include nylon 4,6, nylon 6, nylon 6,
6, nylon 6,10, nylon 6,12, nylon 1
2 and the like and copolymers thereof, such as nylon 6/6,
6 / 6,10, nylon 6 / 6,12 and the like.
Further, acrylamide and its derivatives, and poly-β-alanine copolymers obtained by polymerizing acrylamide and its derivatives and other vinyl monomers in the presence of metal alcoholate can be mentioned. Besides this, amine, amide, urea,
A polymer having a nitrogen-containing group such as urethane and triazine may be used. These polymers containing formaldehyde-reactive nitrogen may be used alone or in combination of two or more, without any limitation. The addition amount of these polymers is 0.005 to 2.0 parts by weight. If the amount added is less than 0.005 parts by weight, the thermal stability will decrease, and if it exceeds 2.0 parts by weight, the aging discoloration property will deteriorate.

The following compounds may be mentioned as hindered phenolic antioxidants. n-octadecyl-3- (3'5'-di-t-butyl-4'-hydroxyphenyl) -propionate, n-octadecyl-3- (3 '
-Methyl-5'-t-butyl-4'-hydroxyphenyl) -propionate, n-tetradecyl-3- (3 '
5'-t-butyl-4'-hydroxyphenyl) -propionate, 1,6-hexanediol-bis- (3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate), 1,4-butanediol-bis- (3 -(3,5-di-t-butyl-4-hydroxyphenyl) -propionate), triethylene glycol-bis- (3- (3-t-butyl-5-methyl-4)
-Hydroxyphenyl) -propionate), tetrakis- (methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate methane,
3,9-bis (2- (3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy) -1,1-dimethylethyl) 2,4,8,10-tetraoxaspiro (5,5) undecane, N, N '-Bisu 3
-(3'5'-di-t-butyl-4-hydroxyphenol) prepionyl hexamethylene diamine, N, N '
-Tetramethylene bis-3- (3'-methyl-5'-t
-Butyl-4-hydroxyphenol) propionyldiamine, N, N'-bis- (3- (3,5-di-t-butyl-4-hydroxyphenol) propionyl) hydrazine, N-salicyloyl-N'-salicylidenehydrazine, 3- (N -Salicyloyl) amino-1,2,4-
Triazole, N, N'-bis (2- (3- (3,5-
Di-butyl-4-hydroxyphenyl) propionyloxy) ethyl) oxyamide and the like. These antioxidants may be used alone or in combination of two or more, without any limitation. The amount of hindered phenolic antioxidant added is 0.01 to 2.
0 parts by weight. If the added amount is less than 0.01 parts by weight, the tensile strength retention after heat aging is low,
If the addition amount exceeds 2.0 parts by weight, the mold deposit property is remarkably deteriorated. The hindered phenolic antioxidant may be added during polymerization or before polymerization of the polymer before unstable terminal treatment. It may be added at the time of extrusion granulation, which is usually added, and is not limited in any way.

The fatty acid ester compound consisting of a polyhydric alcohol and a fatty acid preferably comprises at least one saturated or unsaturated fatty acid containing 10 or more carbon atoms and a polyhydric alcohol containing 2 to 6 carbon atoms. It was induced. Examples of the polyhydric alcohol used to adjust the fatty acid ester compound include ethylene glycol, diethylene glycol, triethylene glycol,
Propylene glycol Dipropylene glycol, butanediol, pentanediol, hexanediol, glycerin, diglycerin, triglycerin, threitol, erythritol, pentaerythritol, arabitol, ribitol, xylitol, sorbite, sorbitan, sorbitol, mannitol 1
More than a seed. As fatty acids, capric acid, lauric acid, myristic acid, palmitic acid stearic acid, 12
-Hydroxystearic acid, araginic acid, behenic acid,
Examples thereof include lignoceric acid, cerotic acid, montanic acid, melissic acid, and ceroplastic acid. Unsaturated aliphatic carboxylic acid comprises undecylenic acid, oleic acid, elaidic acid, cetrainic acid, erucic acid, brassic acid, sorbic acid linoleic acid, linolenic acid, arachidonic acid, propiolic acid, stearolic acid and such components. Examples thereof include naturally occurring fatty acids and mixtures thereof. These fatty acids may be substituted with a hydroxy group. Of the above fatty acid ester compounds, preferably fatty acid ester derived from a fatty acid selected from palmitic acid, stearic acid, behenic acid, montanic acid and a polyhydric alcohol selected from glycerin, pentaerythritol, sorbitan and sorbitol. . These fatty acid ester compounds may or may not have a hydroxyl group. There is no restriction. For example, it may be a monoester or a diester or triester.
The hydroxyl group may be blocked with boric acid or the like. Examples of preferred fatty acid ester compounds include glycerin monopalmitate, glycerin dipalmitate, glycerin tripalmitate, glycerin monostearate, glycerin distearate, glycerin tristearate, glycerin monobehenate, glycerin dibehenate, glycerin triglyceride. Behenate, glycerin monomontanate, glycerin dimontanate, glycerin trimontanate, pentaerythritol monopalmitate,
Pentaerythritol dipalmitate, pentaerythritol tripalmitate, pentaerythritol tetrapalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate, pentaerythritol monobehenate, pentaerythritol Dibehenate, pentaerythritol tribehenate, pentaerythritol tetrabehenate, pentaerythritol monomontanate,
Pentaerythritol dimontanate, pentaerythritol trimontanate, pentaerythritol tetramontanate, sorbitan monopalmitate, sorbitan dipalmitate, sorbitan tripalmitate, sorbitan monostearate, sorbitan distearate,
Sorbitan tristearate, sorbitan monobehenate, sorbitan dibehenate, sorbitan tribehenate, sorbitan monomontanate, sorbitan dimontanate, sorbitan trimontanate, sorbitol monopalmitate, sorbitol dipalmitate, sorbitol tripalmitate , Sorbitol monostearate, sorbitol distearate, sorbitol tristearate, sorbitol monobehenate, sorbitol dibehenate, sorbitol tribehenate sorbitol monomontanate, sorbitol dimontanate,
Sorbitol trimontanate. Further, as an aliphatic ester compound having a hydroxyl group blocked with boric acid or the like, a boric acid ester of glycerin monofatty acid ester (Japanese Patent Laid-Open No. Sho 49-49).
-60762). These fatty acid ester compounds may be used alone or as a mixture of two or more kinds. The amount of the fatty acid ester compound added is 0.005 to 2.0 parts by weight. If the addition amount is less than 0.005 parts by weight, the mold deposit property is poor, and if the addition amount exceeds 2.0 parts by weight, the thermal stability is deteriorated.

In order to impart desired properties to the resin composition of the present invention depending on its purpose, conventionally known additives such as heat stabilizers such as amino-substituted triazines,
Amide-based release agents such as ethylene bis-stearyl amide, 12-hydroxyethylene bis-stearyl amide, erucic acid amide, and oleic acid amide, antistatic agents such as polyethylene glycol, polypropylene glycol, polyethylene glycol alkyl ether, and other surfactants, UV absorbers, light stabilizers, organic polymer materials, glass fibers, carbon fibers, potassium titanate fibers, organic fibers, inorganic or organic fibrous materials such as glass beads, talc, calcium carbonate, etc. A filler and a pigment such as carbon black may be added and contained.

Thermal stabilizers such as amino-substituted triazines include guanamine (2,4-diamino-sym-triazine) and melamine (2,4,6-triamino-sym).
-Triazine), N-butylmelamine, N-phenylmelamine, N, N-diphenylmelamine, N, N-diallylmelamine, N, N ', N "-triphenylmelamine, N-methylolmelamine, N, N'. -Dimethylolmelamine, N, N ', N "-trimethylolmelamine, benzoguanamine (2,4-diamino-6-phenyl-sym-triazine), 2,4-diamino-6-methyl-sym-triazine, 2 , 4-diamino-6-butyl-sym-triazine, 2,4-diamino-6-benzyloxy-sym-triazine, 2,4-diamino-6-butoxy-sym-triazine, 2,4-diamino-6- Cyclohexyl-sym-triazine, 2,4
-Diamino-6-chloro-sym-triazine, 2,4
-Diamino-6-mercapto-sym-triazine,
2,4-dioxy-6-amino-sym-triazine (amelite), 2-oxy-4,6-diamino-sy
Examples include m-triazine (amerine), N, N ′, N′-tetracyanoethylbenzoguanamine and the like.

The ultraviolet absorbers are benzotriazole type ultraviolet absorbers and oxalic acid anilide type ultraviolet absorbers. Examples of the benzotriazole-based ultraviolet absorber include 2- (2′-hydroxy-5′-methyl-phenyl) benzotriazole and 2- (2′-hydroxy-).
3 ', 5'-di-t-butyl-phenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-di-isoamyl-phenyl) benzotriazole, 2- (2 '
-Hydroxy-3 ', 5'-bis- (α, α-dimethylbenzyl) phenyl) benzotriazole, 2- (2'
-Hydroxy-4'-octoxyphenyl) benzotriazole and the like. On the other hand, as the oxalic acid anilide-based ultraviolet absorber, for example, 2-ethoxy-2′-ethyl oxalic acid bisanilide, 2-ethoxy-5-t-butyl-2′-ethyl oxalic acid bisanilide, 2-ethoxy-3'-dodecyl oxalic acid bisanilide and the like can be mentioned. These ultraviolet absorbers may be used alone or in combination of two or more.

As the hindered amine light stabilizer, 4
-Acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-2,2
6,6-Tetramethylpiperidine, 4- (phenylacetoxy) -2,2,6,6-tetramethylpiperidine 4
-Benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-methoxy-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,26,6-
Tetramethylpiperidine, 4-cyclohexyloxy-
2,2,6,6-tetramethylpiperidine, 4-benzyloxy-2,2,6,6-tetramethylpiperidine,
4-phenoxy-2,2,6,6-tetramethylpiperidine, 4- (ethylcarbamoyloxy) -2,2
6,6-Tetramethylpiperidine, 4- (cyclohexylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine, 4- (phenylcarbamoyloxy)-
2,2,6,6-tetramethylpiperidine, bis (2,2
2,6,6-Tetramethyl-4-piperidine) -carbonate, bis (2,2,6,6-tetramethyl-4-piperidyl) -oxalate, bis (2,2,6,6-tetramethyl-4) -Piperidyl) -malonate, bis (2,2,6,6-tetramethyl-4-piperidyl)-
Sebacate, bis (2,2,6,6-tetramethyl-4
-Piperidyl) -adipate, bis (2,2,6,6-
Tetramethyl-4-piperidyl) -terephthalate,
1,2-bis (2,2,6,6-tetramethyl-4-piperidyloxy) -ethane, α, α′-bis (2,2,2
6,6-Tetramethyl-4-piperidyloxy) -p-
Xylene, bis (2,2,6,6-tetramethyl-4-
Piperidyl) tolylene-2,4-dicarbamate, bis (2,2,6,6-tetramethyl-4-piperidyl)-
Hexamethylene-1,6-dicarbamate, tris (2,2,6,6-tetramethyl-4-piperidyl)-
Benzene-1,3,5-tricarboxylate, tris (2,2,6,6-tetramethyl-4-piperidyl)-
Examples thereof include benzene-1,3,4-tricarboxylate. The hindered amine light stabilizers may be used alone or in combination of two or more. It may also be used in combination with an ultraviolet absorber.

The form of addition of these additives may be powder or in a molten state. The addition method is generally carried out by blending the polyacetal resin and the additive together in an extruder and kneading them. The extruder at this time may be uniaxial or biaxial. It may be added during the polymerization. The temperature of the extruder is 180-2
The temperature is 40 ° C., and may be appropriately selected within this range without any limitation.

The composition of the present invention can be molded by any of molding methods such as extrusion molding, injection molding, compression molding, vacuum molding, blow molding and foam molding.

[0023]

The present invention will be described in detail with reference to the following examples. In these,% and parts by weight in the formula are based on weight. Heat aging resistance, heat stability of the resin composition of the present invention,
The aging discoloration property, the calcium ion content in the aliphatic carboxylic acid calcium salt, the quantification method of the chlorine ion content, and the mold deposit property evaluation method were evaluated according to the following methods.

(Formaldehyde gas generation amount): 3 g of the end-stabilized polyacetal resin was placed in an aluminum container and melted at 230 ° C. for 60 minutes under a nitrogen stream (6 normal liters / hour), and the formaldehyde gas generated at that time was generated. Was absorbed in a 1 mol / liter sodium sulfite solution and titrated with 0.01 N sulfuric acid to determine the amount of formaldehyde gas generated. It is expressed in ppm per unit weight of polyacetal.

(Heat resistance aging evaluation condition): 140 ° C.
A test piece molded under the following molding conditions was placed in a Gar oven under the above environment, and deterioration of physical properties was observed. Molding conditions Molding machine: Toshiba Corp. IS-80A Cylinder temperature: 200 ° C Injection pressure: 60 kg / cm ² G Injection time: 15 seconds Cooling time: 25 seconds Mold temperature: 70 ° C Physical property measurement conditions Device: Shimadzu ) Autograph AG-1000B Tensile speed: 5 mm / min Between chucks (Thermal stability): The polyacetal resin composition was retained in an injection molding machine with a cylinder temperature of 250 ° C., and the thermal stability was evaluated by the silver generation time at that time. It was

(Aging discoloration): A test piece after heat aging at 140 ° C. was observed for aging discoloration bL value (JIS Z-8730) by the following apparatus (conditions). Device: Suga Test Instruments Handy Color Tester HC-T (quantification method of calcium ion content): 1 g of aliphatic carboxylic acid calcium salt in methanol / water (2/1) 10
ml was added and sonication was carried out for 1 hour. Then, it filtered using filter paper, the filtrate was injected into the ion chromatograph, and the calcium ion content was quantified.

Apparatus: electric conductivity detector waters 431 Column: Shim-pack IC-C1 (150 mm X 5.0 mm) Injection volume: 100 μL (method for determining chlorine ion content): 1 g of aliphatic carboxylic acid calcium salt in methanol / 10 ml of water (2/1)
Was added and ultrasonic treatment was performed for 1 hour. Then, it filtered using filter paper, the filtrate was injected into the ion chromatograph, and the chlorion content was quantified.

Apparatus: electric conductivity detector WATERS 431 Column: WATERS IC-PACK Anion
HR (75mm X 4.6mm) Injection volume: 100μL (Mold deposit evaluation method): Toshiba IS-100E molding machine Molding conditions: Cylinder temperature 210 ℃ Mold temperature 40 ℃ Injection time / cooling time = 10 seconds / 10 seconds Thunk back 2mm Mold deposit property judgment standard (shot number 500) No mold deposit is generated: ○ Cavity and gas venting part is generated: ×

[0029]

Examples 1-9 and Comparative Examples 1-7 Trioxane and sterically hindered hindered phenolic antioxidant triethylene glycol-bis- (3- (3-t-butyl-5-methyl-4-hydroxyphenyl)) Propionate) 100
1,3-dioxolane (4.0% by weight) to which ppm was added was copolymerized, and then unstable terminals were obtained to obtain a polyacetal copolymer (MI (190 ° C.) 10 g / 10 min) having a formaldehyde gas generation amount of 1100 ppm. . To 100 parts by weight of this polymer, the aliphatic carboxylic acid calcium salt shown in Table 1 and triethylene glycol-bis-
As a polymer containing 0.3 part by weight of (3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate) and formaldehyde-reactive nitrogen, nylon 6 /
0.05 parts by weight of a terpolymer of 6,6 / 6,10 and 0.1 parts by weight of glycerin monostearate as a fatty acid ester compound were added, and the mixture was granulated at 200 ° C. and commercialized. After drying this at 80 ° C. for 5 hours, a test piece was molded and evaluated for heat aging resistance, aging discoloration and thermal stability. The results are shown in Tables 1 and 2.

[0030]

Examples 10 to 13 The same operations as in Examples 1 to 9 were performed except that the type of the aliphatic carboxylic acid calcium salt was changed. The results are shown in Table 3.

[0031]

Examples 14 and Comparative Examples 8 to 9 The same operations as in Examples 1 to 9 were performed except that the polyacetal copolymer having a formaldehyde gas generation amount of 410 ppm was used. The results are shown in Table 3.

[0032]

[Embodiment 15] Formaldehyde gas generation amount 150 pp
Example 1 except that the polyacetal copolymer of m was changed.
The same operation as -9 was performed. The results are shown in Table 3.

[0033]

Example 16 The same operations as in Examples 1 to 9 were performed except that the fatty acid ester compound was changed to 0.1 part by weight of glycerin monobehenate. The results are shown in Table 3.

[0034]

Example 17 Trioxane and sterically hindered hindered phenolic antioxidant triethylene glycol-bis-
(3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate) 100 ppm was added to copolymerize 1,3-dioxolane (4.0% by weight), and the unstable terminal treatment of this polymer was performed. Before carrying out, 0.3 part by weight of triethylene glycol-bis- (3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate) was added, after which end stabilization of the crude copolymer was carried out. went. The amount of formaldehyde gas generated from the resulting polyacetal copolymer is 120 ppm and MI (190 ° C) = 1
It was 0 g / 10 minutes. As a polymer containing formaldehyde-reactive nitrogen in 100 parts by weight of this end-stabilized polyacetal copolymer, nylon 6/6, 6/6, 10
0.05 parts by weight of the terpolymer of Table 1 and 0.1 parts by weight of glycerin monostearate as a fatty acid ester compound
0.1 parts by weight of the calcium salt of an aliphatic carboxylic acid shown in 1 above was added to granulate and produce a product. After this was dried, heat aging resistance, aging discoloration property and heat stability were evaluated. The results are shown in Table 3.

[0035]

Example 18 The comonomer of Example 17 was prepared from the sterically hindered hindered phenolic antioxidant triethylene glycol-bis- (3- (3-t-butyl-5-methyl-4-methyl-4-.
Hydroxyphenyl) propionate) was added to 1,4-butanediol formal (4.0% by weight), and this was copolymerized with trioxane, and triethylene glycol was added before the end stabilization treatment as in Example 17. -Bis- (3- (3-t-butyl-5-methyl-
0.3 parts by weight of 4-hydroxyphenyl) propionate) was added to carry out a terminal stabilization treatment of the polymer. The resulting polyacetal copolymer (MI (190 ° C.) = 9.
The amount of formaldehyde gas (9g / 10min) is 140
It was ppm. As a polymer containing 100 parts by weight of this terminal-stabilized polyacetal copolymer, the aliphatic carboxylic acid calcium salt shown in Table 3 and formaldehyde-reactive nitrogen, nylon 6/6, 6/6, 10 terpolymer 0.3. 05 parts by weight and 0.1 part by weight of glycerin monostearate as a fatty acid ester compound were added, respectively, and granulated, dried and molded, and evaluated for heat aging resistance, aging discoloration property and heat stability. The results are shown in Table 3.

[0036]

Example 19 Sterically hindered hindered phenolic antioxidant triethylene glycol-bis- (3- (3-t
-Butyl-5-methyl-4-hydroxyphenyl) propionate) was added to 10 ppm of 1,3-dioxolane (4.0% by weight) and trioxane were copolymerized, and the obtained polymer was terminated in the same manner as in Example 17. Prior to the stabilization treatment, 0.3 part by weight of triethylene glycol-bis- (3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate) was added to carry out a polymer end stabilization treatment. It was The resulting polyacetal copolymer (formaldehyde gas generation amount 130 ppm, MI = 10.0
g / 10 min) 0.05 part by weight of ternary copolymer of nylon 6/6, 6/6, 10 as a polymer containing 100 parts by weight of aliphatic carboxylic acid calcium salt and formaldehyde reactive nitrogen shown in Table 3. Parts, and 0.1 part by weight of glycerin monostearate as a fatty acid ester compound were added, granulated, dried and molded, and heat aging resistance, aging discoloration property and heat stability were evaluated. The results are shown in Table 3.
It was shown to.

[0037]

Example 20 Triethylene glycol-bis- (3- (3
-T-butyl-5-methyl-4-hydroxyphenyl)
Propionate) was added to the comonomer in an amount of 500 ppm, the 1,3-dioxolane and trioxane were copolymerized by the same method as in Example 17, and the obtained polymer was subjected to terminal stabilization treatment. Completed polyacetal copolymer (formaldehyde gas generation amount 130ppm,
MI = 10.0 g / 10 minutes) Nylon 6/6, 6/6, as a polymer containing 100 parts by weight of the aliphatic carboxylic acid calcium salt shown in Table 3 and formaldehyde reactive nitrogen.
0.05 parts by weight of the terpolymer of 10 and 0.1 parts by weight of glycerin monostearate as a fatty acid ester compound were added, respectively, and granulated, dried and molded to obtain heat aging resistance, aging discoloration and heat stability. An evaluation was made. The results are shown in Table 3.

As can be seen from Tables 1 to 3, the polyacetal resin composition containing an aliphatic carboxylic acid calcium salt having a calcium ion content of 1 to 50 ppm and a chlorine ion content of 10 to 100 ppm is The aging discoloration property, thermal stability, and mold deposit property were superior to those of the polyacetal resin composition containing an aliphatic calcium carboxylate outside the above range.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

[Table 3]

[0042]

EFFECT OF THE INVENTION The resin composition of the present invention is a polyacetal resin composition having a calcium ion content of 1 to 50 ppm and an aliphatic carboxylic acid calcium salt having a chlorine ion content of 10 to 100 ppm, and is heat resistant. Excellent aging, thermal stability and mold deposit,
Moreover, the aging discoloration property is also good. Therefore, the resin composition of the present invention can be provided as a material that significantly improves the molding work environment and is suitable for fields requiring heat aging resistance such as automobile applications.

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[Procedure amendment]

[Submission date] October 6, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

[0029]

Examples 1 to 9 and Comparative Examples 1 to 7 Trioxane and sterically hindered hindered phenolic antioxidant pentaeryth
Lithyl-tetrakis (3- (3,5-di-t-butyl-
4-hydroxyphenyl) propionate) 100 pp
1,3-dioxolane (4.0% by weight) to which m was added was copolymerized, and then unstable terminals were obtained to obtain a polyacetal copolymer (MI (190 ° C.) 10 g / 10 minutes) having a formaldehyde gas generation amount of 1100 ppm. . In 100 parts by weight of this polymer, the aliphatic carboxylic acid calcium salt shown in Table 1 and triethylene glycol-bis- (3-
As a polymer containing 0.3 part by weight of (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate) and formaldehyde-reactive nitrogen, nylon 6,6 was added .
05 parts by weight, and 0.1 parts by weight of glycerin monostearate as a fatty acid ester compound were added,
Granulated and commercialized at ℃. After drying this at 80 ° C. for 5 hours, a test piece was molded and evaluated for heat aging resistance, aging discoloration and thermal stability. The results are shown in Tables 1 and 2.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction content]

[0034]

Example 17 Trioxane and sterically hindered hindered phenolic antioxidant pentaerythrityl-tetrakis
(3- (3,5-di-t-butyl -4-hydroxyphenyl) propionate) 100 ppm added 1,3
-Dioxolane (4.0% by weight) was copolymerized and triethyleneglycol-bis- (3- (3-t-butyl-5-methyl-4-methyl-4-bis- (3- (3-t-butyl-5-methyl-4-methan-4-
0.3 parts by weight of hydroxyphenyl) propionate) was added, and the end of the crude copolymer was then stabilized.
The amount of formaldehyde gas generated from the resulting polyacetal copolymer is 120 ppm and MI (190 ° C) = 10 g /
There was 10 minutes. Table 3 shows that 100 parts by weight of this end-stabilized polyacetal copolymer has 0.05 parts by weight of nylon 6,6 as a polymer containing formaldehyde-reactive nitrogen, and 0.1 parts by weight of glycerin monostearate as a fatty acid ester compound. 0.1 parts by weight of aliphatic carboxylic acid calcium salt was added, and the mixture was granulated and made into a product. After this was dried, heat aging resistance, aging discoloration property and heat stability were evaluated. The results are shown in Table 3.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Correction content]

[0035]

Example 18 The comonomer of Example 17 is used as a sterically hindered hindered phenolic antioxidant pentaerythrityl-.
1,4-butanediol formal (4.0% by weight) added with 100 ppm of tetrakis (3- (3,5-di-t-butyl -4-hydroxyphenyl) propionate) was added, and this was copolymerized with trioxane. Similarly to Example 17, triethylene glycol-bis- (3- (3-t-butyl-5-methyl-4) was used before the end stabilization treatment.
-Hydroxyphenyl) propionate) was added in an amount of 0.3 part by weight to carry out terminal stabilization treatment of the polymer. The resulting polyacetal copolymer (MI (190 ° C) = 9.9
g / 10 min) formaldehyde gas generation amount is 140p
It was pm. In 100 parts by weight of this end-stabilized polyacetal copolymer , 0.05 parts by weight of nylon 6,6 as a polymer containing the aliphatic carboxylic acid calcium salt shown in Table 3 and formaldehyde reactive nitrogen, and glycerin monostea as a fatty acid ester compound 0.1 parts by weight of each rate was added, and the mixture was granulated, dried and molded, and evaluated for heat aging resistance, aging discoloration property and heat stability. The results are shown in Table 3.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction content]

[0036]

Example 19 Sterically hindered hindered phenolic antioxidant pentaerythrityl-tetrakis (3- (3,5
-Di-t-butyl -4-hydroxyphenyl) propionate) was added to 10 ppm of 1,3-dioxolane (4.0% by weight), and trioxane was copolymerized, and the obtained polymer was terminated in the same manner as in Example 17. Prior to the stabilization treatment, 0.3 part by weight of triethylene glycol-bis- (3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate) was added to carry out a polymer end stabilization treatment. It was The resulting polyacetal copolymer (formaldehyde gas generation amount 130 ppm, MI = 10.0 g
/ 10 minutes) 0.05 parts by weight of nylon 6,6 as a polymer containing 100 parts by weight of the aliphatic carboxylic acid calcium salt and formaldehyde-reactive nitrogen shown in Table 3, and glycerin monostearate as a fatty acid ester compound of 0. 1
Each part by weight was added, granulated, dried and molded, and heat aging resistance, aging discoloration and thermal stability were evaluated. The results are shown in Table 3.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0037

[Correction method] Change

[Correction content]

[0037]

Example 20 Pentaerythrityl-tetrakis (3-) added to the comonomer 1,3-dioxolane
(3,5-di-t-butyl -4-hydroxyphenyl)
Propionate) was added to the comonomer in an amount of 500 ppm, the 1,3-dioxolane and trioxane were copolymerized by the same method as in Example 17, and the obtained polymer was subjected to terminal stabilization treatment. Completed polyacetal copolymer (formaldehyde gas generation amount 130ppm,
(MI = 10.0 g / 10 minutes) 0.05 parts of nylon 6,6 as a polymer containing 100 parts by weight of the aliphatic carboxylic acid calcium salt shown in Table 3 and formaldehyde reactive nitrogen.
Parts by weight and 0.1 parts by weight of glycerin monostearate as a fatty acid ester compound were added, respectively, and granulated, dried and molded to evaluate heat aging resistance, aging discoloration property and heat stability. The results are shown in Table 3.

Claims (5)

[Claims] 1. A calcium ion content of 1 to 50 ppm relative to 100 parts by weight of a polyacetal resin,
A polyacetal resin composition obtained by adding 0.01 to 1.0 part by weight of an aliphatic carboxylic acid calcium salt having a chlorine ion content of 10 to 100 ppm. 2. The polyacetal resin is 23 under a nitrogen stream.
The polyacetal resin composition according to claim 1, which has a formaldehyde gas generation amount of 500 ppm or less when heated at 0 ° C. for 60 minutes. 3. A composition containing 0.005 to 2.0 parts by weight of a polymer containing formaldehyde-reactive nitrogen.
2. The polyacetal resin composition according to 2. 4. A hindered phenolic antioxidant 0.
The polyacetal resin composition according to claims 1 to 3, which is obtained by adding 01 to 2.0 parts by weight. 5. The polyacetal resin composition according to claim 1, wherein 0.005 to 2.0 parts by weight of a fatty acid ester compound consisting of a polyhydric alcohol and a fatty acid is added.