JPH06832B2 - Method for producing oxymethylene copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Prior Art] It is known, for example, from JP-B-44-5234 to obtain a polyacetal homopolymer or copolymer by bulk polymerization of trioxane alone or trioxane and a cyclic ether.

Since the obtained polymer is thermally unstable as it is, in the case of a homopolymer, the terminal group is blocked by esterification or the like, and in the case of a copolymer, the unstable terminal portion is decomposed and removed. Although stabilized, it is necessary to deactivate the catalyst and stop the polymerization reaction prior to the stabilization.

That is, oxymethylene homopolymers and copolymers obtained by cationically polymerizing trioxane, etc., gradually depolymerize unless a catalyst remaining in them is deactivated, and a remarkable decrease in molecular weight occurs, or thermal It becomes an extremely unstable polymer.

Regarding the deactivation of boron trifluoride-based polymerization catalyst, Japanese Patent Publication No. 55
-45087 and Japanese Patent Publication No. 55-50485 disclose a method in which a trivalent phosphorus compound is added after bulk polymerization of trioxane and the like with a boron trifluoride-based catalyst.

<Problems to be Solved by the Invention> However, even if the boron trifluoride-based polymerization catalyst is deactivated with a trivalent phosphorus compound, the deactivation effect is not sufficient, and depolymerization still occurs when the polymer is melted. Occurs and a decrease in molecular weight is seen. Particularly when the polymer is melted at a high temperature of 230 ° C. or higher, the molecular weight is remarkably reduced.

Therefore, the inventors of the present invention have achieved the present invention as a result of solving the above-mentioned problems of the prior art and earnestly examining a method for producing an oxymethylene copolymer having excellent thermal stability.

<Means for Solving the Problems> That is, the present invention provides a mixture of trioxane and a cyclic ether with boron trifluoride, boron trifluoride hydrate, and an organic compound containing boron trifluoride and an oxygen atom or a sulfur atom. In the presence of at least one polymerization catalyst selected from the group consisting of coordination compounds with and in the production of oxymethylene copolymers containing oxymethylene units and other oxyalkylene units by bulk polymerization, the following general formula
(I) Addition of a hindered amine compound represented by (I) to deactivate the boron trifluoride-based catalyst, further addition of a stabilizer, and heating at a temperature range of 100 to 260 ° C to produce an oxymethylene copolymer. Is the way.

(In the formula, Y is a hydrogen atom, -O ^·, alkyl group, substituted alkyl group, an alkenyl group, an aralkyl group, an aryl group, a substituted aryl group or an acyl group.

A is And R ¹ represents a lower alkyl group. Z is -O- or And R ² represents a hydrogen atom or a lower alkyl group.
n shows the valence of and shows the integer of 1-6. Represents a residue derived from an organic carboxylic acid or an inorganic oxygen acid.
Also, when n = 1, R ³ and R ^{4 each} represent a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group, an aryl group, a substituted aryl group or an acyl group. ).

The cyclic ether used in the present invention, the following general formula (II)
Means a compound represented by.

(However, Y ^{1 to} Y ^{4 in the} formula represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen-substituted alkyl group having 1 to 6 carbon atoms, and they may be the same or different.
X represents a methylene or oxymethylene group, which may be substituted with an alkyl group or a halogen-substituted alkyl group, and m represents an integer of 0 to 3. Alternatively, X is - (CH ₂₎
p-O-CH ₂ - or _{-O-CH 2 - (CH 2} ) p-O-CH 2 - is a even better, in this case a m = 1, p is an integer from 1 to 3 . ) Among the cyclic ethers represented by the general formula (II), as particularly preferable compounds, ethylene oxide, propylene oxide, 1,3-dioxolane, 1,3-dioxane,
1,3-dioxepane, 1,3,5-trioxepane,
1,3,6-trioxycan, epichlorohydrin and the like can be mentioned.

The copolymerization amount of the cyclic ether of the present invention needs to be in the range of 0.1 to 10 mol%, particularly preferably 0.2 to 5 mol% with respect to trioxane, and if it is 0.1 mol% or less, unstable terminal parts are decomposed. When removed and stabilized, the polymer yield is low and productivity is reduced, which is not preferable. Also, 10 mol%
The above is not preferable because the melting point and crystallinity of the polymer are lowered and the mechanical strength and moldability are deteriorated.

The polymerization catalyst of the present invention comprises one or more compounds selected from the group consisting of boron trifluoride, a boron trifluoride hydrate and a coordination compound of an organic compound having an oxygen or sulfur atom and boron trifluoride, a gas. Used in the form of a liquid, a liquid or a suitable organic solvent.

Examples of the organic compound having an oxygen atom or a sulfur atom which forms a coordination compound with boron trifluoride include alcohol, ether, phenol and sulfide.

Among these catalysts, a coordination compound of boron trifluoride is particularly preferable, and boron trifluoride / diethyl etherate and boron trifluoride / dibutyl etherate are particularly preferably used.

Examples of the solvent for the polymerization catalyst of the present invention include benzene, toluene, aromatic hydrocarbons such as xylene, n-hexane,
Aliphatic hydrocarbons such as n-heptane and cyclohexane, alcohols such as methanol and ethanol, halogenated hydrocarbons such as chloroform, dichloromethane, 1,2-dichloroethane, ketones such as acetone and methyl ethyl ketone are used. .

The addition amount of the polymerization catalyst is 5 × with respect to 1 mol of trioxane.
It is in the range of 10 ⁻⁶ to 1 × 10 ⁻¹ mol, particularly preferably in the range of 1 × 10 ⁻⁵ to 1 × 10 ⁻² mol.

Various devices for polymerizing trioxane alone or trioxane and cyclic ether in a bulk are known, but the bulk polymerization used in the present invention is not particularly limited by the device, and 10% by weight or less based on trioxane. Then,
It can also be applied to a polymerization reaction carried out in the presence of an organic solvent such as cyclohexane.

In the bulk polymerization, an apparatus having a strong stirring ability and capable of controlling the reaction temperature is particularly preferably used because rapid solidification and heat generation occur during the polymerization.

As the bulk polymerization apparatus of the present invention having such performance, a kneader having a sigma type stirring blade, a cylindrical barrel as a reaction zone, and a screw having coaxial and many interrupted peaks in the barrel, A mixer that operates so that the interruption and the teeth protruding on the inner surface of the barrel engage.
Ordinary screw extruder with a pair of intermeshing parallel screws in a long case with a jacket for heating or cooling, two horizontal stirring shafts with multiple paddles, and the shafts rotating simultaneously in the same direction In this case, a self-cleaning mixer or the like that rotates while maintaining a slight clearance between the paddle surface and the inner surface of the case of each other can be mentioned.

Also, in bulk polymerization, a strong stirring ability is required because it solidifies rapidly in the initial stage of the polymerization reaction, but once it is pulverized, a large stirring ability is not required thereafter, so the bulk polymerization step is performed twice. It may be divided into stages.

The bulk polymerization reaction temperature is preferably in the temperature range from the melting point to the boiling point of trioxane, that is, in the range of 60 to 115 ° C, particularly preferably in the range of 60 to 90 ° C.

At the initial stage of the polymerization, the temperature in the polymerization reaction device tends to rise particularly due to the reaction heat and the frictional heat caused by solidification, so it is desirable to control the reaction temperature by passing cooling water through the jacket. .

In the present invention, a hindered amine compound represented by the following general formula is used to deactivate the boron trifluoride-based catalyst.

(In the formula, Y is a hydrogen atom, -O ^·, alkyl machines, substituted alkyl group, an alkenyl group, an aralkyl group, an aryl group, .A showing a substituted aryl group or an acyl group And R ¹ represents a lower alkyl group. Z is -O- or And R ² represents a hydrogen atom or a lower alkyl group.
n shows the valence of and shows the integer of 1-6. Represents a residue derived from an organic carboxylic acid or an inorganic oxygen acid.
Also, when n = 1, R ³ and R ^{4 each} represent a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group, an aryl group, a substituted annealing group or an acyl group. ).

In the compound represented by the general formula (I) used in the present invention, examples of the alkyl group include methyl, ethyl, propyl, butyl, hexyl, octyl and the like, and examples of the substituted alkyl group include chloroethyl, hydroxyethyl, epoxypropyl, Examples include cyanoethyl, examples of alkenyl groups include vinyl and allyl, examples of aralkyl groups include benzyl and phenylethyl, and examples of aryl groups and substituted aryl groups include phenyl group, α-naphthyl group, β-naphthyl group. Group, p-tolyl group, o-tolyl group, chlorophenyl group and the like, and the acyl group includes formyl, acetyl and the like. Examples of the lower alkyl group include methyl, ethyl, propyl, butyl and the like.

Examples of the organic carboxylic acid residue represented by are the following carboxylic acid residues.

Acetic acid, propionic acid, butyric acid, caproic acid, caprylic acid,
Capric acid, lauric acid, myristic acid, stearic acid, behenic acid, acrylic acid, methacrylic acid, crotonic acid, oleic acid, linolenic acid, ricinolenic acid, hydroxyacetic acid, aminoacetic acid, aminocrotonic acid, phenylacetic acid, phenoxyacetic acid, 3 , 5-di-tert-butyl-4-hydroxyphenylpropionic acid, laurylthiopropionic acid, benzoic acid, toluic acid, p-tert-butylbenzoic acid, p-hydroxybenzoic acid, salicylic acid, p-chlorobenzoic acid, p -Methoxybenzoic acid, p-nitrobenzoic acid, 3,5-di-tert-butyl-4-hydroxybenzoic acid, nicotinic acid, isonicotinic acid, thiophene-2-carboxylic acid, pyrrolidonecarboxylic acid, piperidine-4-carboxylic acid Acid, orotic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, Belin acid, sebacic acid, decamethylene dicarboxylic acid, maleic acid, itaconic acid, acetylene dicarboxylic acid, bis (3,5-di - third
Butyl-4-hydroxybenzyl) malonic acid, thiodipropionic acid, thiodiglycolic acid, methylenebisthioglycolic acid, iminodiacetic acid, tartaric acid, malic acid, thiomalic acid, dihydrotartaric acid, epoxysuccinic acid, 3,4-
Dioxythiophene dicarboxylic acid, 1,4-biscarboxyethylpiperazine, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, 5-bicyclo [2.2.1] heptene-2,3-dicarboxylic acid, 5-bicyclo [2.2.2.] Heptene-2,3-dicarboxylic acid, propanetricarboxylic acid, butanetricarboxylic acid, butenetricarboxylic acid, nitrilotriacetic acid, citric acid, triscarboxyethyl isocyanurate, triscarboxymethyl isocyanurate, trimellitate Acid, butanetetracarboxylic acid, ethylenetetracarboxylic acid, ethylenediaminetetraacetic acid, pyromellitic acid, 1
3-bis (aminomethyl) cyclohexane-N, N,
Examples thereof include N ', N'-tetraacetic acid.

Examples of the inorganic oxygen acid residue represented by are the following inorganic oxygen acid residues.

Phosphoric acid, phosphorous acid, phosphonic acid, phosphonous acid, substituted phosphonic acid, substituted phosphonous acid, silicic acid, diorganosilicic acid,
Examples thereof include boric acid and carbonic acid.

Further, a part of the acid groups of the organic carboxylic acid and the inorganic oxygen acid may be an ester of monovalent or polyvalent phenols or alcohols.

When it is an ester of polyhydric phenol or polyhydric alcohol, two or more organic carboxylic acids or inorganic oxygen acids are linked by polyhydric phenol or polyhydric alcohol as shown in the following formula. It may have been done.

(P is an integer of 1 to 10 and m is an integer of 0 to 2 is a polyhydric phenol or polyhydric alcohol residue.) Examples of the polyhydric phenol or polyhydric alcohol residue represented above include the following. The polyhydric phenol or polyhydric alcohol residue of is mentioned.

Examples of polyhydric phenols include hydroquinone, 4,
4'-isopropylidene diphenol (bisphenol A), 4,4'-cyclohexylidene diphenol,
4,4'-methylenebisphenol, 4,4'-sulfobisphenol, 2,5-di-tert-butylhydroquinone, 2,3,6-trimethylhydroquinone, 2-methylresorcin, 2,2'-methylenebis (4- Methyl-
6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 2,2 '
-Methylenebis [4-methyl-6- (α-methylcyclohexyl) phenol], 2,2'-n-butylidenebis (4,6-di-methylphenol), bis-1,1-
(2'-Hydroxy-3 ', 5'-di-methylphenyl) -3,5,5-trimethyl, 2,2'-cyclohexylidenebis (4-ethyl-6-tert-butylphenol), 2,2 ′ -Isopropylbenzylidene-bis (4
-Ethyl-6-tert-butylphenol), 2,2'-thiobis (4-tert-butyl-6-methylphenol),
2,2'-thiobis (4-methyl-6-tert-butylphenol), 2,2'-thiobis (4,6-tert-butylphenol), 4,4'-methylenebis (2-methyl-6)
-Tert-butylphenol), 4,4'-isopropylidenebis (2-phenylphenol), 4,4'-n-butylidenebis (3-methyl-6-tert-butylphenol), 4,4'-cyclohexylidenebis (2-tert-butylphenol), 4,4'-cyclohexylidenebis (2-cyclohexylphenol), 4,4'-benzylidenebis (2-tert-butyl-5-methylphenol), 4,4'-oxobis (3-methyl-6-isopropylphenol), 4,4'-thiobis (2-methyl-6-tert-butylphenol), 4,4'-thiobis (3-methyl-6-tert-butylphenol), 4,4 ′
-Sulfobis (3-methyl-6-tert-butylphenol), bis (2-methyl-4-hydroxy-5-tert-butylbenzyl) sulfide, 1,1,3-tris (2 ')
-Methyl-4'-hydroxy-5'-tert-butylphenyl) butane, 2,2-bis (3'-tert-butyl-4'-
Hydroxyphenyl) -4- (3 ″, 5 ″ -di-tert-butyl 4 ″ -hydroxyphenyl) butane, 2,2-bis- (2′-methyl-5′-tert-butyl-4′-hydroxyphenyl) ) -4- (3 ", 5" -di-tert-butyl 4 "
-Hydroxyphenyl) butane and the like.

Examples of the polyhydric alcohol include ethylene glycol,
Diethylene glycol, triethylene glycol, 1,
2-propanediol, 1,3-propanediol,
1,2-butanediol, 1,3-butanediol,
1,4-butanediol, neopentyl glycol, thiodiethylene glycol, 1,6-hexanediol,
1,10-decanediol, 1,4-cyclohexanediol, 1,4-dicyclohexanedimethanol, 1,4
-Phenylene dimethanol, hydrogenated bisphenol A, glycerin, trimethylolmethane, trimethylolethane, tris (2-hydroxyethyl) isocyanurate and the like.

Examples of monohydric phenols include phenol, cresol, 4-tert-butylphenol, octylphenol, nonylphenol, 2,4-tert-butylphenol, 2-cyclohexylphenol and the like.

Examples of monohydric alcohols include methanol, ethanol, octanol, 2-ethylhexanol, cyclohexanol, decanol, lauryl alcohol, tetradecal, hexadecanol, octadecanol, methoxyethanol, ethoxyethanol, butoxyethanol, phenoxyethanol, ethoxyethoxy. Examples include ethanol and butoxyethoxyethanol.

Examples of the compound represented by the formula (I) used in the present invention include the following compounds (I-1 to 30).

I-1 3-n-butyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro [4.5] decane-2,
4-dione, I-2 3-n-butyl-7,7,8,9,9-pentamethyl-1,3,8-triazaspiro [4.5] decane-
2,4-dione, I-3 3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro [4.5] decane-
2,4-dione, I-4 3-n-octyl-7,7,8,9,9-pentamethyl-1,3,8-triazaspiro [4.5] decane-2,4-dione, I-5 3-allyl-7,7,9,9-tetramethyl-
1,3,8-Triazaspiro [4.5] decane-2,4-
Dione, I-6 3-glycidyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro [4.5] decane-2,
4-dione, I-7 3-glycidyl-7,7,8,9,9-pentamethyl-1,3,8-triazaspiro [4.5] decane-
2,4-dione, I-8 3-octadecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro [4.5] decane-
2,4-dione, I-9 3-cyclohexyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro [4.5] decane-
2,4-dione, I-10 1,3,7,7,8,9,9-heptamethyl-
1,3,8-Triazaspiro [4.5] decane-2,4-
Dione, I-11 7,7,8,9,9-pentamethyl-1,3,3
8-triazaspiro [4.5] decane-2,4-dione, I-12 3-n-octyl-8-benzyl-7,7,
9,9-Tetramethyl-1,3,8-triazaspiro [4.5] decane-2,4-dione, I-13 bis (9-aza-8,8,10,10-tetramethyl-3-ethyl -1,5-Dioxaspiro [5.5] -3
-Undecylmethyl) methyliminodiacetate, I-14 bis (9-aza-8,8,10,10-tetramethyl-3-ethyl-1,5-dioxaspiro [5.5] -3
-Undecylmethyl) -pentaerythritol diphosphite, I-15 tetrakis (9-aza-3,8,8,10,
10-pentamethyl-1,5-dioxaspiro [5,5
5] -3-undecylmethyl) .4,4'-butylidene bis (2-tert-butyl-5-methylphenol) .diphosphite, I-16 tetrakis (9-aza-8,8,10,10-tetramethyl) -3-Ethyl-1,5-dioxaspiro [5.
5] -3-undecylmethyl) / hydrogenated bisphenol A
Diphosphite, I-17 hexakis (9-aza-8,8,10,10-tetramethyl-1,5-dioxaspiro [5.5] -3-undecylmethyl) -1,1,3-tris (2 -Methyl-4
-Hydroxy-5-tert-butylphenyl) butane triphosphite, I-18 bis (9-aza-8,8,10,10-tetramethyl-3-ethyl-1,5-dioxaspiro [5.5]- Three
-Undecylmethyl) -pentaerythritol diphosphate, I-19 bis (9-aza-8,8,10,10-tetramethyl-3-ethyl-1,5-dioxaspiro [5.5] -3
-Undecylmethyl) carbonate, I-20 bis (9-aza-8,8,10,10-tetramethyl-3-ethyl-1,5-dioxaspiro [5.5] -3
-Undecylmethyl) -hydrogenated bisphenol A dicarbonate, I-21 bis (9-aza-3,8,8,10,10-pentamethyl-1,5-dioxaspiro [5.5] -3-undecyl Methyl) -ethylene glycol dicarbonate, I-22 3-allyl-7,7,8,9,9-pentamethyl-1,3,8-triazaspiro [4.5] decane-2,
4-dione, I-23 3-octadecyl-7,7,8,9,9-pentamethyl-1,3,8-triazaspiro [4.5] decane-2,4-dione, I-24 3-cyclohexyl- 7,7,8,9,9-pentamethyl-1,3,8-triazaspiro [4.5] decane-2,4-dione, I-25 bis (9-aza-8,8,9,10,10 -Pentamethyl-3-ethyl-1,5-dioxaspiro [5.5]
-3-undecylmethyl) -pentaerythritol diphosphite I-26 bis (9-aza-8,8,9,10,10-pentamethyl-3-ethyl-1,5-dioxaspiro [5.5]
-3-undecylmethyl) methyliminodiacetate, I-27 tetra (9-aza-3,8,8,9,10,10-
Hexamethyl-1,5-dioxaspiro [5.5] -3-
Undecylmethyl) -4,4'-butylidene bis (2-
Tertiary butyl-5-methylphenol) diphosphite, I-28 tetra (9-aza-8,8,9,10,10-pentamethyl-3-ethyl-1,5-dioxaspiro [5.
5] -3-undecylmethyl) / hydrogenated bisphenol A
-Diphosphite, I-29 hexakis (9-aza-8,8,9,10,10-
Pentamethyl-1,5-dioxaspiro [5.5] -3-
Undecylmethyl) -1,3-tris (2-methyl-4)
-Hydroxy-5-tert-butylphenyl) butane-triphosphite, I-30 bis (9-aza-8,8,9,10,10-pentamethyl-3-ethyl-1,5-dioxaspiro [5.5]
-3-undecylmethyl) -hydrogenated bisphenol A dicarbonate.

Among these hindered amine compounds, a tertiary amine type hindered amine compound is particularly preferably used because the obtained polymer has an excellent color tone.

The hindered amine compound of the present invention may be added as it is, but may be added as a solution of an organic solvent in order to promote contact with the polymerization catalyst. Examples of the organic solvent at that time include aromatic hydrocarbons such as benzene, toluene and xylene, aliphatic hydrocarbons such as n-hexane, n-heptane and cyclohexane, alcohols such as methanol and ethanol, chloroform, dichloromethane and the like.
Halogenated hydrocarbons such as 1,2-dichloroethane,
Ketones such as acetone and methyl ethyl ketone may be mentioned.

The addition amount of the hindered amine compound is preferably such that the number of nitrogen atoms forming the hindered amine structure is equal to or more than the number of boron atoms of the boron trifluoride-based catalyst used. Even if the number of nitrogen atoms is less than the number of boron atoms, the catalyst deactivating effect can be seen, but the heat resistance stability of the obtained polymer is slightly lowered. Therefore, the addition amount is adjusted according to the desired degree of heat stability. There is a need.

Examples of the stabilizer used in the present invention include antioxidants, and specific examples thereof include triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], Pentaerythrityl-
Tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-)
Hydroxyphenyl) propionate], N, N'-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-
4-Hydroxyphenyl) propionate], 2,4-
Bis- (n-octylthio) -6- (4-hydroxy-
3,5-di-tert-butylanilino) -1,3,5-triazine, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2,
2-thiobis (4-methyl-6-tert-butylphenol), 3,5-di-tert-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5
-Tris (4-tert-butyl-4-hydroxy-2,6
-Dimethylbenzyl) isocyanuric acid, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1-bis (2-methyl-4-hydroxy-5-tert- 3-butylphenyl) butane, 2,
2'-methylene-bis (4-methyl-6-tert-butylphenol), N, N'-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl]
Hindered phenol compounds such as hydrazine, tetrakis (2,4-di-tert-butylphenyl) -4,4 '
-Biphenylenephosphonite, tris (2,4-di-tert-butylphenyl) phosphite, tetrakis (2,2
4-di-tert-butylphenyl) -4,4'-biphenylene diphosphonite, distearyl pentaerythritol diphosphite, ditridecyl pentaerythritol diphosphite, dinonylphenyl pentaerythritol diphosphite, tris (nonylphenyl) ) Phosphite, bisphenol A pentaerythritol phosphite, trilauryl trithiophosphite, tetraphenyl tetra (tridecyl) pentaerythritol tetraphosphite, hydrogenated bisphenol A phosphite polymer, tris (2,4-di-tert-butylphenyl) ) Phosphite, diphenyl monodecyl phosphite, didecyl monophenyl phosphite, phosphorus compounds such as tridecyl phosphite, dilauryl thiodipropionate, distearyl thiophene Sulfur such as dipropionate, ditridecylthiodipropionate, 4,4'-thio-bis (3-methyl-5-tert-butylphenol) and tridecylthiopropionic acid ester, pentaerythritol and dodecylthiopropionic acid ester The system compounds are listed.

Further, a so-called formaldehyde absorbent capable of reacting with formaldehyde to absorb formaldehyde can also be used as the stabilizer of the present invention, and an amide compound, a urethane compound, a pyridine derivative, a pyrrolidone derivative, a urea derivative, a triazine derivative. , Hydrazine derivatives, and amidine compounds, specifically, N, N
-Dimethylformamide, N, N-dimethylacetamide, N, N-diphenylformamide, N, N-diphenylacetamide, N, N-diphenylbenzamide,
Homopolymers of lactams such as N, N, N ', N'-tetramethyladipamide, oxalic acid dianilide, adipic acid dianilide, α- (N-phenyl) acetanilide, nylon 6, nylon 11 and nylon 12 or Copolymer, adipic acid, sebacic acid, decanedicarboxylic acid,
Divalent carboxylic acids such as dimer acid and ethylenediamine,
Polyamide homopolymers or copolymers derived from diamines such as tetramethylenediamine, hexamethylenediamine, metaxylylenediamine, polyamide copolymers derived from lactams and dicarboxylic acids and diamines, polyacrylamide, polymethacryl Amide, N, N-bis (hydroxymethyl) suberamide,
Poly (γ-methylglutamate), poly (γ-ethylglutamate), poly (N-vinyllactam), poly (N
-Derived from amide compounds such as vinylpyrrolidone), diisocyanates such as toluene diisocyanate and diphenylmethane diisocyanate, and glycols such as 1,4-butanediol and polymer glycols such as poly (tetramethylene oxide) glycol, polybutylene adipate, and polycaprolactone. Polyurethane,
Melamine, benzoguanamine, acetoguanamine, N-
Butylmelamine, N-phenylmelamine, N, N'-diphenylmelamine, N, N'-N "-triphenylmelamine, N-methylolmelamine, N, N'-dimethylolmelamine, N, N ', N"- Trimethylolmelamine, 2,4-diamino-6-benzyloxytriazine, 2,4-diamino-6-butoxytriazine, 2,
Triazine derivatives such as 4-diamino-6-cyclohexyltriazine, melem and melam, N-phenylurea, N, N'-diphenylurea, thiourea, N-phenylthiourea, N, N'-diphenylthiourea, nonamethylene poly Urea derivatives such as urea, phenylhydrazine,
Diphenylhydrazine, benzaldehyde hydrazone, semicarbazone, 1-methyl-1-phenylhydrazone, thiosemicarbazone, 4- (dialkylamino)
Hydrazones of benzaldehyde, 1-methyl-1-phenylhydrazone, hydrazine derivatives such as thiosemicarbazone, dicyandiamide, guanzidine, guanidine, aminoguanidine, guanine, guanacrine, guanoclor, guanoxane, guanosine, amiloride,
Amidine compounds such as N-amidino-3-amino-6-chloropyrazinecarboxamide, poly (2-vinylpyridine), poly (2-methyl-5-vinylpyridine),
Poly (2-ethyl-5-vinylpyridine), 2-vinylpyridine-2-methyl-5-vinylpyridine copolymer,
Examples thereof include pyridine derivatives such as 2-vinylpyridine-styrene copolymer.

Among these stabilizers, especially triethylene glycol-bis [3- (tertiary-butyl-5-methyl-4-hydroxyphenyl) propionate], pentaerythrityl-tetrakis [3- (3,5-di-tertiary] 3-butyl-4-
Hydroxyphenyl) propionate], 1,3,5-
Tris (4-tert-butyl-3-hydroxy-2,6-
Dimethylbenzyl) isocyanuric acid, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, N, N'-hexamethylenebis (3 , 5-Di-tertiary-butyl-4-hydroxy-hydrocinnamide) are preferred, and these compounds and formaldehyde absorbents, especially dimer acid polyamide, melamine, guanamine, benzoguanamine, N. -Methylolated melamine, N-methylolated benzoguanamine, thermoplastic polyurethane resin, dicyandiamide, guanidine, poly (N-vinylpyrrolidone), poly (2-vinylpyridine), polyurea, melem, and melam are particularly preferable.

The amount of stabilizer added is 0 based on the oxymethylene copolymer.
01 to 10.0% by weight, preferably 0.02 to 5.0% by weight, more preferably 0.05 to 3.0% by weight, if less than 0.01% by weight, the effect of improving heat resistance is not sufficient, and if it exceeds 10.0% by weight, the stabilizer is It is not preferable because it deposits in the form of white powder on the surface of the methylene copolymer and reduces the commercial value.

In the production method of the present invention, although not particularly necessary, it is preferable to use a terminal decomposition accelerator in combination with the stabilizer because the stable terminal is rapidly decomposed and removed. As the terminal decomposition accelerator, alkali metal hydroxide, alkali metal weak inorganic acid salt,
Alkali metal organic acid salt, alkali metal alkoxide, alkali metal phenoxide, alkaline earth metal hydroxide,
Examples thereof include alkaline earth metal weak inorganic acid salts, alkaline earth metal organic acid salts, alkaline earth metal alkoxides, and alkaline earth metal phenoxides. Specifically, lithium, sodium, potassium, magnesium, calcium, or barium Hydroxide, carbonate, phosphate, silicate,
Borate, formate, acetate, propionate, butyrate,
Oxalate, malonate, glutarate, succinate,
Adipate, benzoate, phthalate, isophthalate, terephthalate, P-toluate, benzenesulfonate, P-toluenesulfonate, P-sulfobenzoate, sulfoisophthalate, Sulfoterephthalate, methoxide, ethoxide, isopropoxide, n-
Examples include butoxide and phenoxide.

Preferred are magnesium hydroxide, calcium hydroxide and barium hydroxide.

The amount of the terminal decomposition accelerator added is 0.01 to 10.0% by weight, preferably 0.02 to 5.0% by weight, based on the oxymethylene copolymer.
More preferably, it is 0.05 to 3.0% by weight. 0.01% by weight
If it is less than 10% by weight, the effect of addition is not obtained, and if it exceeds 10% by weight, the hydrolysis resistance of the polymer is deteriorated.

In the present invention, a mixture of trioxane and a cyclic ether and / or a cyclic acetal is bulk polymerized using a boron trifluoride-based catalyst, and after deactivating the catalyst by adding a hindered amine compound to the obtained polymer, Add Stabilizer 10
Temperature range of 0 to 260 ° C, preferably melting point of copolymer to 240
The oxymethylene copolymer is produced by heating in the temperature range of ° C. At temperatures lower than 100 ° C, decomposition of unstable terminals is slow, and it takes a long time for the polymer to stabilize. On the other hand, if the temperature exceeds 260 ° C, not only the unstable terminal but also the polymer main chain is severely decomposed, which is not preferable.

The present invention provides a method for producing a polymer having excellent thermal stability by deactivating a polymerization catalyst of an oxymethylene copolymer with a hindered amine compound, and even if a deactivated contact exists in the polymer. The stabilizer of the present invention effectively acts on a compound deactivated by a compound to produce an oxymethylene copolymer excellent in heat resistance which cannot be obtained by a polymer deactivated by a conventional phosphorus compound. It provides a method.

The oxymethylene copolymer produced according to the present invention is excellent in moldability, mechanical properties, melt stability and heat aging resistance, so that it can be used in a wide range of applications such as mechanical mechanism parts, automobile parts, and electric / electronic parts. You can

<Example> Next, the present invention will be described with reference to Examples and Comparative Examples. In addition,
Surface condition, mechanical properties, relative viscosity ηr, thermal decomposition rate K, polymer melting point (Tm) of molded articles shown in Examples and Comparative Examples
And the crystallization temperature (Tc) were measured as follows.

Surface condition of molded product: ASTM No. 1 dumbbell test piece and Izod impact test piece using an injection molding machine having an injection capacity of 5 ounces, with a cylinder temperature of 230 ° C., a mold temperature of 60 ° C. and a molding cycle of 50 seconds. Was injection molded. The surface state of the obtained ASTM No. 1 dumbbell test piece was visually observed.

Mechanical Properties: Using the ASTM No. 1 dumbbell test piece obtained by the above injection molding, the tensile properties were measured according to the ASTM D-638 method. Also, using the Izod impact test piece, ASTM D-
The impact strength was measured according to the 256 method.

Relative viscosity ηr: p-chlorophenol 100m containing 2% α-pinene
In 1 l, 0.5 g of polymer was dissolved and measured at a temperature of 60 ° C.

Thermal decomposition rate Kx: Kx means the decomposition rate when left at x ° C for a certain period of time. Using a thermobalance device, leave about 10 mg of sample at x ° C in an air atmosphere, and use the following formula. I asked.

Kx = (Wo−Wl) × 100 / Wo% where Wo is the sample weight before heating and Wl is the sample weight after heating.

The thermal balance device used was a thermal analyzer 1090/1091 manufactured by Dupont.

Polymer melting point (Tm), crystallization temperature (Tc): Using a differential scanning calorimeter, the temperature was raised at a heating rate of 10 ° C./min in a nitrogen atmosphere, and after measuring the polymer melting point (Tm), 10 ℃ /
The temperature was lowered in minutes, and the crystallization temperature (Tc) was measured.

Reference Example 1 A 3-liter kneader having two Σ-type stirring blades was heated to 60 ° C., and 3.0 kg of trioxane and 75 of 1,3-dioxolane were used.
g, and further, boron trifluoride / diethyl etherate as a catalyst was added at 200 ppm as a 10% benzene solution based on the weight of trioxane, and the mixture was stirred at 30 rpm.

The contents solidified within a few minutes and the temperature inside the system rose due to reaction heat and frictional heat, so cooled air was passed through the Σ-type stirring blade, and the rotation speed was further reduced to 10 rpm to a maximum temperature of 80 ° C.
Controlled by.

The stirring was continued as it was, and after 60 minutes, the polymer was taken out. The obtained polymer was a white powder with ηr = 2.45.

This polymer is referred to as oxymethylene copolymer A.

Reference Example 2 In Reference Example 1, instead of 1,3-dioxolane,
The polymer was bulk polymerized in the same manner as in Reference Example 1 except that 44 g of ethyloxide was used.

The obtained polymer was a white powder with ηr = 2.44.

This polymer is referred to as oxymethylene copolymer B.

Examples 1 to 6 and Comparative Examples 1 to 3 Various hindered amine compounds were added to the oxymethylene copolymer A obtained in Reference Example 1 as a 15 to 20% benzene solution at the ratio shown in Table 1, and two sheets were added. The catalyst was deactivated by stirring in a kneader with a Σ-type stirring blade at 35 ° C for 15 minutes at 30 rpm. As a stabilizer (antioxidant), 0.5% by weight of pentaerythrityl-tetrakis [3- (3,5
-Di-t-butyl-4-hydroxyphenyl) propionate] ("Irganox" 1010 manufactured by Ciba-Geigy) and added in 210 minutes over 10 minutes.
After the temperature was raised to ° C, the mixture was stirred at the same temperature and 30 rpm for 20 minutes.

For comparison, polymers were made using triphenylphosphine instead of hindered amine compounds.

The results of measuring the physical properties of the obtained polymer are summarized in Table 1.

From the measurement results in Table 1, particularly the thermal decomposition rates K222 and K240, it is apparent that the polymer deactivated by the use of the hindered amine compound is superior in heat resistance stability to the polymer deactivated by the use of triphenylphosphine. Further, the larger the added amount of the hindered amine compound, the more excellent the heat resistance stability. It can be seen that even if the kind of the hindered amine compound changes, the heat resistance stability of the obtained polymer does not change and the mechanical properties are not affected.

Examples 7-14 Pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] as stabilizer (antioxidant) (Ciba Geigy (Ci
ba-Geigy) "Irganox" 1010)
A polymer was produced in the same manner as in Example 2 except that the addition amount of was changed.

In addition, as a stabilizer (antioxidant) other than "Irganox" 1010, triethylene glycol-bis- [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] (Ciba・ Geigy (Ci
ba-Geigy) "Irganox" 24
5), 1,6-hexanediol-bis- [3- (3,
5-di-t-butyl-4-hydroxyphenyl) propionate] (“Irganox” 259 manufactured by Ciba-Geigy), dinonylphenyl pentaerythritol diphosphite (Adeka Argus ( AdekaArgus) "Mark" PEP-4),
1,3,5-Tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid ("Cyanox" 1790, manufactured by American Cyanamid), 2, 2'-methylene-
A polymer was produced using bis (4-methyl-6-t-butylphenol) ("Sumilizer" MDP-S manufactured by Sumitomo Chemical Co., Ltd.).

The results of measuring the physical properties of these polymers are summarized in Table 2.

It is apparent from Table 2 that a polymer having excellent heat resistance stability can be obtained as the amount of the antioxidant added is increased. Also,
The use of antioxidants other than "Irganox" 1010 will result in polymers with heat resistance comparable to that of "Irganox" 1010.

Examples 15 to 18 Polymers were produced in the same manner as in Example 2 except that calcium hydroxide was used as a terminal decomposition accelerator in a ratio shown in Table 3 in addition to the stabilizer (antioxidant) (Example 15). .

A polymer was produced in the same manner as in Example 15, except that magnesium hydroxide (Example 16), barium hydroxide (Example 17) and potassium carbonate (Example 18) were used instead of calcium hydroxide.

Table 3 shows the results of measuring the physical properties of the obtained polymer. From Table 3, it can be seen that the use of the terminal decomposition accelerator in red increases the heat resistance stability of the obtained polymer.

Examples 19 to 22 Pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] as a stabilizer (antioxidant) (Ciba Geigy
-Geigy) "Irganox" 1010) in addition to using a stabilizer (formaldehyde absorber) such as dicyandiamide, melamine, diamic acid polyamide, polyether ester amide in addition to Example 15 and A polymer was produced in the same manner.

The results of measuring the physical properties of these polymers are summarized in Table 4. Table 4
Clearly, it can be seen that heat resistance stability is further improved by using two kinds of stabilizers together.

Examples 23 to 26 Polymers were produced in the same manner as in Examples 2, 10, 16 and 19 except that the copolymer B obtained in Reference Example 2 was used.

Table 5 shows the results of measuring the physical properties of the obtained polymer. It is clear from Table 5 that even when the copolymer B is used, a polymer having the same physical properties as when the copolymer A is used can be obtained.

<Effects of the Invention> As shown in the examples, by using the production method according to the present invention, an oxymethylene copolymer excellent in heat stability can be produced by an extremely simple process without removing the catalyst by washing. be able to.

Claims (1)

[Claims] 1. A mixture of trioxane and a cyclic ether is selected from the group consisting of boron trifluoride, boron trifluoride hydrate and a compounded compound of boron trifluoride and an organic compound containing an oxygen atom or a sulfur atom. In the presence of at least one polymerization catalyst, in bulk polymerization to produce an oxymethylene copolymer containing oxymethylene units and other oxyalkylene units, the following general formula (I) after completion of the polymerization
The hindered amine compound represented by is added to deactivate the boron trifluoride-based catalyst, and a stabilizer is further added.
A method for producing an oxymethylene copolymer, which comprises heating in a temperature range of 0 to 260 ° C. (In the formula, Y is a hydrogen atom, -O ^·, alkyl group, substituted alkyl group, an alkenyl group, an aralkyl group, an aryl group, .A showing a substituted aryl group or an acyl group And R ¹ represents a lower alkyl group. Z is -O- or And R ² represents a hydrogen atom or a lower alkyl group.
n shows the valence of and shows the integer of 1-6. Represents a residue derived from an organic carboxylic acid or an inorganic oxygen acid.
Also, when n = 1, R ³ and R ^{4 each} represent a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group, an aryl group, a substituted aryl group or an acyl group. ).