JP2003026745A - Method for manufacturing polyacetal copolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a polyacetal copolymer having quite a few unstable terminal portions, exhibiting remarkable thermal stability and emitting quite a little amount of formaldehyde at a high polymerization yield by a simple process where deactivation of a catalyst is easy and a washing step is unnecessary. SOLUTION: In manufacturing using a cationically active catalyst (c) a polyacetal copolymer comprising trioxane as a main monomer (a) with a comonomer (b) comprising a cyclic ether and/or a cyclic formal having at least one carbon-carbon bond, an amino-substituted triazine ring-containing compound (d) is added to a reaction product and followed by a melt kneading treatment to deactivate the catalyst (c).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyacetal for deactivating a catalyst by copolymerizing trioxane and a comonomer in the presence of a polymerization catalyst and then adding an amino-substituted triazine ring-containing compound to the copolymerization reaction product. The present invention relates to a method for producing a copolymer. ADVANTAGE OF THE INVENTION According to this invention, the manufacturing process is simplified and the polyacetal copolymer excellent in quality, such as heat stability and a low formaldehyde emission amount, is obtained.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a polyacetal copolymer, a cationic copolymerization using trioxane as a main monomer and a cyclic ether or cyclic formal having at least one carbon-carbon bond as a comonomer is known. Among these cationically active catalysts used for copolymerization, boron trifluoride or a coordination compound of boron trifluoride and an organic compound such as ethers is the most common as a copolymerization catalyst containing trioxane as a main monomer. Widely used industrially.

However, generally used polymerization catalysts such as boron trifluoride require a relatively large amount (for example, 40 ppm or more based on all monomers), and it is difficult to sufficiently deactivate the catalyst after polymerization. However, even if the deactivation treatment is carried out, the decomposition of the substance derived from the catalyst is promoted, the polymerization yield and the degree of polymerization are limited, and a considerable amount of unstable terminal portions are present, which is complicated. There were problems such as the need for a stabilization process.

Japanese Unexamined Patent Publication (Kokai) No. 1-170610 discloses a production method using a heteropolyacid as a catalyst, and the reaction system after completion of polymerization is preferably ammonia, triethylamine, tri-n-butylamine, hindered amine, or the like. Addition and mixing of amines, alkali metal, alkaline earth metal hydroxides, organic acid salts (eg fatty acid salts) and other known catalyst deactivators, or addition and treatment of solutions containing these deactivators It is disclosed that the polymerization catalyst is thereby neutralized and deactivated. However, in this method, a solution of a quenching agent such as water containing 0.1% of tributylamine is added to stop the reaction, and at the same time, it is ground to 200 mesh or less, and washed with acetone and dried.

That is, in the copolymerization method using a catalyst as described above, it is important to deactivate the catalyst after polymerization. If the deactivation is insufficient, the decomposition of the produced copolymer is promoted and the subsequent production is It is a major cause of impairing the stability of the copolymer. Therefore,
In order to sufficiently deactivate the catalyst, a large amount of a deactivator solution is added to the product after the polymerization, and the product is thoroughly washed to remove residual monomers and residues derived from the catalyst, and then the copolymer. Is required to be separated from the treatment liquid, dried, or the monomer is recovered from the cleaning liquid, which is extremely economically disadvantageous.

In order to save the complexity involved in the deactivation treatment of such a catalyst, a method of adding a trivalent phosphorus compound to the resulting copolymer (Japanese Patent Publication No. 55-42085) or a method of adding a hindered amine compound (special Kai 62-257922
However, according to the study of the present inventor, sufficient deactivation cannot be performed, and it is extremely difficult to obtain a copolymer having good thermal stability. In particular, if the polymerization yield at the time of polymerization is increased, the produced polymer becomes more unstable, and complicated stabilization treatment is required in the post process, which does not simplify the process and the stability There is a limit and it is not desirable in terms of quality.

[0007]

The object of the present invention is a simple process which can easily deactivate a catalyst and does not require a washing step, and also has a high polymerization yield and extremely stable unstable end portions. It is an object of the present invention to provide a method for producing a polyacetal copolymer which is low in amount, is extremely stable in terms of heat, and has an extremely small amount of formaldehyde emission.

[0008]

Means for Solving the Problems As a result of earnest studies on the deactivation method in order to achieve the above object, the present inventor has found that an amino-substituted triazine ring-containing compound is added to a reaction product (also referred to as a crude copolymer). It was found that the catalyst can be deactivated extremely easily and reliably by simply adding the mixture as it is and not performing the solution state, and performing melt kneading treatment, and the above object can be achieved, and the present invention has been completed. It was

That is, the first aspect of the present invention is to use a trioxane as a main monomer (a), a cyclic ether and / or a cyclic formal having at least one carbon-carbon bond as a comonomer (b), and a cationic active catalyst (c). In producing a polyacetal copolymer by using, a polyacetal copolymer characterized in that an amino-substituted triazine ring-containing compound (d) is added to a reaction product and melt-kneaded to deactivate the catalyst (c). A method for producing a polymer is provided. The second aspect of the present invention is that the comonomer (b) is 1,3-dioxolane, diethylene glycol formal, 1,4.
Provided is a method for producing a polyacetal copolymer according to the first aspect of the present invention, which is at least one selected from butanediol formal, 1,3-dioxane, and ethylene oxide. The third aspect of the present invention is that the amino-substituted triazine ring-containing compound (d) is melamine, melamine resin, and / or
Also provided is a method for producing the polyacetal copolymer according to the first or second aspect of the present invention, which is an amino-substituted triazine ring-containing spiro compound. A fourth aspect of the present invention provides a method for producing the polyacetal copolymer according to the third aspect of the present invention, wherein the amino-substituted triazine ring-containing spiro compound is a compound represented by the following formula (1).

[0010]

[Chemical 2]

(In the formula, R ¹ and R ² may be the same or different, and are an alkylene group having 1 to 10 carbon atoms and 6 carbon atoms.
The arylene group of 10 or the aralkylene group which these alkylene groups and the arylene group couple | bonded are shown. ) A fifth aspect of the present invention is the polyacetal copolymer according to the fourth aspect of the present invention, wherein in the formula (1), R ¹ and R ² are linear or branched alkylene groups having 1 to 6 carbon atoms. A manufacturing method is provided. A sixth aspect of the present invention is that the amino-substituted triazine ring-containing spiro compound is CTU guanamine, CMTU guanamine, and 3,9-bis [1- (3,5-diamino-
2,4,6-Triazaphenyl) -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5]
5] A method for producing the polyacetal copolymer according to the fourth aspect of the present invention, which is at least one selected from undecane. A seventh aspect of the present invention provides a method for producing a polyacetal copolymer according to any one of the first to sixth aspects of the present invention, wherein the catalyst (c) is inactivated by melt-kneading in the presence of an antioxidant. To do.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. In the present invention, trioxane which is a cyclic trimer of formaldehyde is used as the main monomer (a).

In the present invention, as the comonomer (b),
Cyclic ethers and / or cyclic formal having at least one carbon-carbon bond are used, and any of the known comonomers used for conventional copolymerization with trioxane can be used. Typical examples of such cyclic ethers and cyclic formal include 1,3-dioxolane, diethylene glycol formal, 1,4-butanediol formal, 1,3-dioxane, ethylene oxide, propylene oxide, epichlorohydrin and the like. . Among them, 1,3-dioxolane, diethylene glycol formal, 1,4-butanediol formal, 1,3-dioxane, ethylene oxide and the like are preferable. In addition, cyclic esters such as β-broviolactone and vinyl compounds such as styrene are also used. It is also possible to use a compound having two or more polymerizable cyclic ether groups or cyclic formal groups such as alkylene-diglycidyl ether or diformal as a comonomer for forming a branched or crosslinked molecular structure in the copolymer. . Examples thereof include butanediol dimethylidene glyceryl ether and butanediol diglycidyl ether.

The amount of the comonomer (b) used in the present invention is 0.1 to 20 mol%, preferably 0.2 to 10 mol% based on trioxane. If it is less than 0.1 mol%, the number of unstable terminals increases and the stability deteriorates. If it is too large, the copolymer produced becomes soft and the melting point lowers, which is not preferable.

In the polymerization method of the present invention, a known chain transfer agent, for example, a linear acetal having a low molecular weight such as methylal may be added in order to adjust the degree of polymerization according to the purpose. Further, it is desirable that the polymerization reaction system is substantially free of impurities having active hydrogen, such as water, methanol, formic acid, etc.

As the cation active catalyst (c), known catalysts are used. That is, Lewis acids, especially boron, tin, titanium, phosphorus, arsenic and antimony halides such as boron trifluoride, tin tetrachloride, titanium tetrachloride, phosphorus pentachloride, phosphorus pentafluoride, arsenic pentafluoride and Compounds such as antimony pentafluoride and complex compounds or salts thereof; protic acids such as trifluoromethanesulfonic acid and perchloric acid; isopoly acids; esters of protic acids,
In particular, esters of perchloric acid with lower aliphatic alcohols, such as perchloric acid tert-butyl ester; anhydrides of protic acids, especially trifluoromethanesulfonic anhydride or mixed anhydrides of perchloric acid with lower aliphatic carboxylic acids, Examples thereof include acetyl perchlorate; or ion pair catalysts such as triethyloxonium hexafluorophosphate, triethyloxonium hexafluoroborley, triphenylmethylhexafluorophosphate, and the like.

The amount of the catalyst (c) used varies depending on the kind thereof and can be appropriately changed to control the polymerization reaction. Generally, it is 0.1 to the total amount of the monomers to be polymerized. It is in the range of 500 ppm (hereinafter, weight / weight ppm is shown), preferably 0.5 to 30 ppm.
Is.

The polymerization method of the present invention can be carried out using the same equipment and method as those used for the conventionally known copolymerization of trioxane.
That is, any of a batch type, a continuous type and a semi-continuous type is possible, and a method of using a liquid monomer to obtain a solid powdery lump polymer as the polymerization proceeds is common. As the polymerization apparatus used in the present invention, a reaction vessel with a stirrer which is generally used in a batch system can be used, and as a continuous system, a co-kneader, a twin-screw type continuous extrusion mixer,
The axial paddle type continuous mixer and other continuous polymerization devices such as trioxane proposed so far can be used, and two or more types of polymerization machines can be used in combination.

The polymerization method is not particularly limited, but the trioxane, the comonomer and the polymerization catalyst are sufficiently mixed while maintaining the liquid phase state in advance, and the obtained reaction raw material mixed solution is supplied to the polymerization apparatus and co-produced. If the polymerization reaction is performed,
It is an advantageous and more preferable polymerization method for obtaining a polyacetal copolymer that releases less formaldehyde. In addition, some or all of the monomers and molecular weight regulators,
It is also a preferable method to add a predetermined amount of the catalyst as a solution in which the catalyst is dissolved in advance to the polymerization system. The polymerization temperature is 60 to 120.
It is carried out in the temperature range of ° C.

In the present invention, the amount of unreacted monomer is preferably as small as possible in deactivating the catalyst after polymerization, and the unreacted monomer (the total of the main monomer (a) and the comonomer (b)) is coarse. It is 10% by weight or less, more preferably 5% by weight or less, and particularly preferably 3% by weight or less in the copolymer. Since the main purpose of the present invention is not to wash the crude copolymer, a large amount of residual monomer is not preferable. To reduce unreacted monomer,
Generally, the polymerization rate may be increased to a certain level or more, and in the present invention, this can be easily achieved by appropriately adjusting the amount of the catalyst used and the polymerization time (residence time in the continuous system). Also, after the copolymerization reaction, some residual monomer is evaporated,
It may be vaporized and removed to obtain a predetermined residual monomer amount.

Next, the crude copolymer obtained after the completion of the copolymerization reaction is directly added with the amino-substituted triazine ring-containing compound (d) as a deactivator without washing or the like,
Usually, a melt-kneading process is performed to complete the deactivation of the polymerization catalyst. Examples of the amino-substituted triazine ring-containing compound (d) include melamine, melamine resin, and / or amino-substituted triazine ring-containing spiro compound. The number of triazine rings is not particularly limited, but preferably 1 to 4 and more preferably It is preferable to contain 1 to 2, especially 2 pieces. In particular, a compound having a structure in which two triazine rings are linked by a spiro compound (that is, a compound having a triazine ring at both ends of the spiro compound) is preferable. The triazine ring contains 1,2,3-triazine, 1,
Includes 2,4-triazine and 1,3,5-triazine. Of these, 1,3,5-triazine is preferable. The triazine ring may have a substituent such as an alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 10 carbon atoms, an amino group or a substituted amino group. As the triazine ring, 1,3,5-triazine having an amino group or a substituted amino group as a substituent, particularly a guanamine ring is preferable. The spiro ring part may be a spiro ring composed only of carbon, but a spiro ring having a hetero atom (particularly an oxygen atom) as a constituent atom of the ring is preferable. Examples of such spiro compounds include spiro compounds represented by the above formula (1) and having a guanamine ring at both ends.

In the above formula (1), examples of the alkylene group represented by R ¹ and R ² include linear or branched ones such as methylene, ethylene, propylene, isopropylene, butylene and isobutylene groups. Examples of the arylene group include phenylene and naphthylene groups.
Examples of the aralkylene group include groups in which the alkylene group and the arylene group are linked. Preferred R ¹ and R ² are alkylene groups having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, and particularly preferably ethylene groups. Further, R ¹ and R ² may further have a substituent such as an alkyl group having 1 to 4 carbon atoms such as a methyl group, a phenyl group, an amino group, an N-substituted amino group or the like. Examples of such spiro compound (d) include:
3,9-bis [2- (3,5-diamino-2,4,6-
[Uriazaphenyl) ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane (CTU guanamine), 3,9-bis [1- (3,5-diamino-2,
4,6-Triazaphenyl) methyl] -2,4,8,1
0-Tetraoxaspiro [5,5] undecane (CMT
U guanamine), 3,9-bis [1- (3,5-diamino-2,4,6-triazaphenyl) -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [ 5,5] undecane, 3,9-bis [3- (3,5-
Diamino-2,4,6-riazaphenyl) -1,1-
Dimethylpropyl] -2,4,8,10-tetraoxaspiro [5,5] undecane and other 3,9-bis [(3,5-diamino-2,4,6-triazaphenyl) C1-6 alkyl ] -2,4,8,10-Tetraoxaspiro [5,5] undecane and the like can be mentioned.
These spiro compounds may be water-containing crystallization compounds or anhydrous compounds. Such a spiro compound (d) is, for example, a method of reacting a dioxonitrile having a tetraoxospiro ring with dicyandiamide in an alcoholic organic solvent at high pressure in the presence of a basic catalyst (JP-A-5-32664). ), In an ether organic solvent,
Method of reacting in the presence of a basic catalyst (Japanese Patent Publication No. 44-8)
676) and the like.

Next, the crude copolymer obtained after the completion of the copolymerization reaction is directly added with the amino-substituted triazine ring-containing compound (d) as a deactivator without washing or the like,
Usually, it is melt-kneaded to complete the deactivation of the polymerization catalyst (c). The amount of the amino-substituted triazine ring-containing compound (d) in the present invention is not particularly limited as long as it is an amount sufficient to neutralize and deactivate the catalyst, but is usually 1 with respect to the crude copolymer.
Used at 0-10,000 ppm.

In addition, when the amino-substituted triazine ring-containing compound (d) is added, it is preferable that the crude polymer is a fine powder, and for this purpose, the reactor has a function of sufficiently pulverizing the bulk polymer. It is preferable that the reaction product after polymerization is separately crushed by using a crusher and then contacted with the amino-substituted triazine ring-containing compound (d). Regarding the particle size of the crude copolymer in the deactivation treatment, at least 90% by weight or more is 10 mm or less, preferably 4 mm or less, more preferably 2 mm or less.

In the present invention, the crude copolymer to which the amino-substituted triazine ring-containing compound (d) is added is directly subjected to melt-kneading treatment without washing and the like to complete the deactivation of the catalyst. Melt-kneading process should be performed above the melting point of the copolymer.
A temperature range up to 60 ° C is preferred. If the temperature is higher than 260 ° C, the polymer is decomposed and deteriorated, which is not preferable.

The heat treatment device is not particularly limited, but a device having a function of kneading the melted polymer and preferably a vent function is required, and for example, a uniaxial or multiaxial having at least one vent hole is required. A shaft continuous extrusion kneader, a co-kneader and the like can be mentioned. In the present invention, the polymerization catalyst is completely deactivated in this melt-kneading process.

The melt-kneading treatment is preferably performed in the presence of an antioxidant. As the antioxidant, a substance known as a stabilizer for conventional polyacetal resins, for example, various hindered phenol-based antioxidants and the like are used. For example, 2,6-di-t-butyl-4-methylphenol,
Triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis- [3- (3,3
5-di-t-butyl-4-hydroxyphenyl) propionate], tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) bropionate] methane, N, N′-hexamethylenebis (3 , 5-di-t-
Butyl-4-hydroxyhydrocinnamide), 2-t-
Butyl-6- (3'-t-butyl-5'-methyl-2 '
-Hydroxybenzyl) -4-methylphenyl acrylate, 3,9-bis [2-{(3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy}
Examples include -1,1'-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] -undecane. These hindered phenol-based antioxidants may be partly or wholly added in advance to the main monomer (a) or comonomer (b) before polymerization and polymerized. The antioxidant does not adversely affect the activity of the polymerization catalyst unless the added amount is particularly large, which is one of the preferred embodiments.

Further, at this stage, if necessary, a known substance as a stabilizer for various polyacetal resins may be added without any problem. Further, for example, a filler such as glass fiber, a crystallization accelerator (nucleating agent), a release agent, etc. may be added.

As described above, after the amino-substituted triazine ring-containing compound (d) is added to the crude copolymer and melt-kneaded, it is usually molded into pellets or the like to obtain a product for resin processing. The pellets are dried as needed. When drying, for example, it is dried at 140 ° C. for about 3 hours.

[0030]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited thereto. still,
The terms and measuring methods in Examples and Comparative Examples are as follows. % Or ppm: All are expressed by weight. Melt Index (MI): Shows the melt index (g / 10 min) measured at 190 ° C. This was evaluated as a characteristic value corresponding to the molecular weight. That is, the lower the MI, the higher the molecular weight. Alkaline decomposition rate (amount of unstable portion): Copolymer pellets were crushed and 1 g thereof was added to 100 ml of 50% aqueous methanol solution containing 0.5% ammonium hydroxide, and the mixture was kept in a closed container at 180 ° C. for 45 minutes. After heating, the amount of formaldehyde decomposed and eluted in the liquid was quantitatively analyzed, and is shown as% of the polymer. Heating weight loss rate: 2 g of copolymer pellets in air 2 g
The weight loss rate when heated at 30 ° C. for 45 minutes is shown.
(In Table 1, abbreviated as weight reduction rate.) Formaldehyde emission amount: A sample was filled in a cylinder kept at 200 ° C., melted for 5 minutes, and then the melt was extruded from the cylinder into a closed container. Nitrogen gas was caused to flow into this closed container, formaldehyde contained in the nitrogen gas that came out was dissolved and collected in water, and the formaldehyde concentration in the water was measured to determine the weight of formaldehyde released from the melt. This formaldehyde weight is divided by the weight of the melt to give the amount of formaldehyde (unit: pp
m).

[Examples 1 to 11 and Comparative Examples 1 and 2] As a polymerization reactor, a cross-section in which two circles partially overlap each other,
A continuous mixing reactor equipped with a jacketed barrel for passing a heat (cold) medium on the outside and a large number of paddles for stirring and propelling the inside was provided with two rotating shafts in the longitudinal direction. Hot water of 80 ° C. is passed through the jacket of the reactor, and two rotating shafts are rotated at a constant speed, and one end thereof contains 3.5% of the comonomer shown in Table 1 and 700 ppm of methylal as a chain transfer agent. A mixed solution of trioxane was continuously supplied, and at the same time, a 0.5% cyclohexane solution of boron trifluoride dibutyl etherate (BF ₃ · Bu ₂ O) shown in Table 1 and trifluoromethanesulfonic acid (CF ₃ SO ₃
H) in 0.2% diglyme (ie, diethylene glycol dimethyl ether), acetyl perchlorate (CH ₃ COClO ₄ ) in 0.2% diglyme, or triethyloxonium hexafluorophosphate (Et ₃ O).
A 0.5% methylene chloride solution of PF ₆ ) was continuously added to all the monomers in an amount shown in Table 1 to carry out copolymerization.
However, in Table 1, the addition amount of the polymerization catalyst is a weight ratio (ppm) with respect to the total of all monomers, and in the case of boron trifluoride dibutyl etherate, it is a value as boron trifluoride (BF ₃ ). Then, to the reaction product discharged from the discharge port, the triazine ring-containing spiro compound, melamine, or melamine resin shown in Table 1 was added as a catalyst deactivator, and triethylene glycol- was added as an antioxidant.
Bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] 0.3% was added,
Using a twin-screw extruder with a vent, the mixture was melt-kneaded at a temperature of 220 ° C. and a vacuum degree of the vent portion of 5 mmHg and extruded to prepare pellets. However, in Table 1, the addition amount of the quenching agent is the weight ratio (ppm) to the crude copolymer. After drying the pellets at 140 ° C. for 3 hours, MI measurement, thermal decomposition rate measurement, heating weight loss rate measurement, and formaldehyde emission amount measurement were performed. The results are shown in Table 1. Further, for comparison, boron trifluoride butyl etherate 0.
The same procedure is performed using a 5% cyclohexane solution and using known triphenylphosphine as a quenching agent and bis (2,2,6,6-tetramethyl-4-piperidinyl) sebacate as a hindered amine. It was

Comparative Example 3 A cyclohexane solution of boron trifluoride butyl etherate was used as a catalyst in Example 1.
Polymerization was carried out in the same manner as above, and the reaction product discharged from the discharge port was prepared into a 20% by weight slurry in a 0.1% aqueous solution of triethylamine, deactivated at 80 ° C. for 1 hour, and treated flakes. Was filtered and dried at 100 ° C. for 1 hour. Then, as an antioxidant, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-
Hydroxyphenyl) propionate] 0.3% was added, and the same extrusion and evaluation as in Example 1 were performed.

[0033]

[Table 1]

Abbreviations for comonomers in Table 1 indicate the following. DOXO: 1,3-dioxolane BDFM: 1,4-butanediol formal DEFFM: diethylene glycol formal DXN: 1,3-dioxane EO: ethylene oxide

The following compounds or methods were used as the quenching agent. A: CTU guanamine B: CMTU guanamine C: 3,9-bis [1- (3,5-diamino-2,4,
6-Triazaphenyl) -1,1-dimethylethyl]-
2,4,8,10-Tetraoxaspiro [5,5] undecane D: melamine E: melamine resin F: triphenylphosphine G: bis (2,2,6,6-tetramethyl-4-piperidinyl) sebacate H: Wet quench where 20% of crude copolymer flakes are slurried in 0.1% triethylamine aqueous solution

[0036]

According to the present invention, as compared with the conventional wet method, the dry method simplifies the deactivation step and the washing step is omitted in a very streamlined step, thereby completely removing the polymerization catalyst. Can deactivate. As a result, it is possible to economically produce a polyacetal copolymer of excellent quality that does not cause any troubles such as decomposition and deterioration due to the catalyst, has few unstable portions, is thermally stable, and has an extremely small amount of formaldehyde released. I can.

Claims (7)

[Claims] 1. A main monomer (a) is trioxane,
A cyclic ether and / or cyclic formal having at least one carbon-carbon bond as a comonomer (b),
In producing the polyacetal copolymer using the cationic active catalyst (c), the amino-substituted triazine ring-containing compound (d) is added to the reaction product, and the mixture is melt-kneaded,
A method for producing a polyacetal copolymer, which comprises deactivating the catalyst (c). 2. The comonomer (b) is at least one selected from 1,3-dioxolane, diethylene glycol formal, 1,4-butanediol formal, 1,3-dioxane, and ethylene oxide. Method for producing polyacetal copolymer. 3. The method for producing a polyacetal copolymer according to claim 1, wherein the amino-substituted triazine ring-containing compound (d) is a melamine, a melamine resin, and / or an amino-substituted triazine ring-containing spiro compound. 4. The method for producing a polyacetal copolymer according to claim 3, wherein the amino-substituted triazine ring-containing spiro compound is a compound represented by the following formula (1). [Chemical 1] (In the formula, R ¹ and R ² may be the same or different,
It represents an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, or an aralkylene group in which these alkylene groups and arylene groups are bonded. ) 5. The method for producing a polyacetal copolymer according to claim 4, wherein R ¹ and R ² in the formula (1) are linear or branched alkylene groups having 1 to 6 carbon atoms. 6. The amino-substituted triazine ring-containing spiro compound is CTU guanamine, CMTU guanamine, and 3,9-bis [1- (3,5-diamino-2,4,6-).
Triazaphenyl) -1,1-dimethylethyl] -2,
The method for producing a polyacetal copolymer according to claim 4, which is at least one selected from 4,8,10-tetraoxaspiro [5,5] undecane. 7. The method for producing a polyacetal copolymer according to claim 1, wherein the catalyst (c) is inactivated by melt-kneading in the presence of an antioxidant.