WO2014137126A1 - Method for preparing polyoxymethylene polymer, and polyoxymethylene polymer prepared thereby - Google Patents

Abstract

The present invention relates to a method for preparing a polyoxymethylene polymer, and a polyoxymethylene polymer prepared thereby, and more specifically, to: a method for preparing a polyoxymethylene polymer capable of omitting or simplifying the inactivation of a catalyst, having remarkable thermal stability and enable to reduce the formaldehyde discharged during a preparation process by preparing a polyoxymethylene polymer by using a novel polymerization catalyst and a polymerization terminator; and a polyoxymethylene polymer prepared thereby.

Description

Method for preparing polyoxymethylene polymer and polyoxymethylene polymer prepared therefrom

The present invention relates to a method for producing a polyoxymethylene polymer and a polyoxymethylene polymer prepared therefrom, and more particularly, to prepare a polyoxymethylene polymer using a novel polymerization catalyst and a polymerization terminator, thereby inactivating a catalyst. The present invention relates to a method for preparing a polyoxymethylene polymer and a polyoxymethylene polymer prepared therefrom, which may be omitted or simplified, which is excellent in thermal stability, and which can reduce formaldehyde released in the manufacturing process.

Generally, polyoxymethylene resins are prepared by bulk polymerization, solution polymerization or suspension polymerization of trioxane alone or trioxane with cyclic ethers and / or cyclic acetals to prepare oxymethylene homopolymers or copolymers. Such a method is disclosed in Korean Unexamined Patent Publication No. 10-2002-0074490 (Patent Document 1).

However, the polymer obtained by such bulk polymerization, solution polymerization or suspension polymerization is thermally unstable in itself, so in the case of the homopolymer, the end group is blocked by esterification or the like, and in the case of the copolymer, the unstable end group is decomposed. The polymer is stabilized by removal, and it is necessary to deactivate the catalyst to stop the polymerization reaction before such stabilization step. That is, if the catalyst remaining in the reaction product in the oxymethylene homopolymer and copolymer obtained by cation polymerization of trioxane or the like is not deactivated, depolymerization gradually occurs and the molecular weight of the polymer is significantly lowered, resulting in thermal instability.

In connection with such deactivation of the catalyst, Japanese Unexamined Patent Publication No. 1994-211953 (Patent Document 2) proposes the use of an amine compound and an alkali metal fluoride as the BF ₃ polymerization catalyst deactivator. In the case of inactivation, depolymerization can be prevented only by removing the deactivator through a separate washing step, and the polymer is stabilized so that molecular weight does not decrease during long-term storage.

As such, in order to solve the conventional problems, a polymerization catalyst that can be completely deactivated and a deactivator capable of effectively and completely deactivating such a polymerization catalyst are developed so that a cleaning step for removing the polymerization catalyst or deactivator is not necessary. The method for producing polyoxymethylene polymer having low thermal stability and unstable portion is required.

[Preceding technical literature]

(Patent Document 1) Republic of Korea Patent Publication No. 10-2002-0074490

(Patent Document 2) Japanese Unexamined Patent Publication No. 1994-211953

In order to solve the above problems, an object of the present invention is to provide a method for producing a polyoxymethylene polymer that can omit or simplify the deactivation process by using a novel polymerization catalyst capable of complete deactivation.

It is also an object of the present invention to provide a method for producing a polyoxymethylene polymer which is capable of perfect deactivation of a polymerization catalyst, excellent thermal stability, and minimized unstable portions by using a polymerization terminator optimized for deactivation of a novel polymerization catalyst. .

The present invention for achieving the above object is an oxymethylene homopolymer consisting of a repeating unit represented by the following formula (2) using a polymerization catalyst and a carbodiimide-based polymerization terminator represented by the following formula (1) or formula (2) It relates to a method for producing a polyoxymethylene polymer for producing an oxymethylene copolymer in which the repeating unit represented by the following and the repeating unit represented by the following formula (3) is bonded randomly.

[Formula 1]

(In Formula 1, X is nitrogen or oxygen, Y is SiR ₁ R ₂ R ₃ , n is 1 or 2.)

[Formula 2]

[Formula 3]

(In Formula 3, X ₁ and X ₂ are each independently hydrogen or (C 1 -C 6) alkyl, not hydrogen at the same time, x is an integer selected from 2 to 6, n of formula 2 and m of formula 3 is 1 Is an integer selected from to 200.)

The carbodiimide-based polymerization terminator may be a compound represented by the following formula (4).

[Formula 4]

(In Formula 4, R ₁ and R ₂ are each independently (C1-C20) alkyl, (C6-C20) aryl, (C1-C20) alkoxy, (C3-C20) cycloalkyl, (C2-C7) alkenyl , (C3-C20) heterocycloalkyl, (C4-C20) heteroaryl, wherein the alkyl, aryl, alkoxy, cycloalkyl, alkenyl, heterocycloalkyl of R ₁ and R ₂ are (C1) One or more selected from alkyl, halogen, nitro, cyano, amino may be further substituted, provided that at least one of R ₁ and R ₂ is (C 3 -C 20) cycloalkyl, (C 6 -C 20) Cyclic substituents selected from aryl, (C3-C20) heterocycloalkyl, (C4-C20) heteroaryl.)

The polymerization catalyst of Chemical Formula 1 may be selected from the following chemical formulas.

The carbodiimide-based polymerization terminator may be selected from one or two or more of the following Chemical Formulas 4-1 and 4-2.

[Formula 4-1]

(N in Formula 4-1 is an integer selected from 50 to 200.)

[Formula 4-2]

The polymerization catalyst may be included in an amount of 0.03 to 200 ppm based on the total monomer content, and the content of the polymerization terminator may be included in an amount of 10 to 5000 ppm based on the total monomer content.

The polymerization catalyst may be dissolved and added with an organic solvent, and the organic solvent may be ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, or di One kind or two or more kinds may be selected from the group consisting of ethylene glycol methyl butyl ether, triethylene glycol butyl ether, propylene glycol dimethyl ether and dipropylene glycol dimethyl ether.

In addition, the present invention for achieving the above object relates to a polyoxymethylene polymer prepared by the above-described manufacturing method.

The terminal Formate content of the polyoxymethylene polymer is 3.0 to 8.0 μmol / g-POM, and the amount of formaldehyde released may be 50 to 200 ppm.

The present invention can omit or simplify the deactivation process using a novel polymerization catalyst, and effectively deactivate the polymerization catalyst by using a polymerization terminator optimized for the new polymerization catalyst, and have excellent thermal stability and low polyunsaturation. There is an advantage to prepare oxymethylene polymers.

Hereinafter, preferred embodiments of the polyoxymethylene polymer of the present invention and the polyoxymethylene polymer prepared therefrom will be described in detail with reference to preferred embodiments. The invention can be better understood by the following examples, which are intended for purposes of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Hereinafter, each structure of this invention is demonstrated more concretely.

The polyoxymethylene polymer polymerized by the present invention is a homopolymer composed of an oxymethylene repeating unit represented by the following Chemical Formula 2, using a polymerization catalyst represented by the following Chemical Formula 1 and a carbodiimide polymerization terminator, or The repeating unit of and the repeating unit of Formula 3 may be a copolymer bonded randomly.

[Formula 1]

(In Formula 1, X is nitrogen or oxygen, Y is SiR ₁ R ₂ R ₃ , n is 1 or 2.)

In Formula 1, R ₁ , R ₂ and R ₃ may be each independently selected from (C1-C20) alkyl, (C6-C20) aryl, (C1-C20) alkoxy, and (C4-C20) heteroaryl There is,

Alkyl, aryl, alkoxy and heteroaryl of R ₁ , R ₂ and R ₃ may be further substituted with one or more selected from (C 1 -C 5) alkyl, halogen, nitro, cyano, amino.

Specifically, in Chemical Formula 1, X is oxygen, and R ₁ , R _2, and R ₃ are each independently (C 1 -C 20) alkyl, and more preferably, the polymerization catalyst of Chemical Formula 1 is selected from the following Chemical Formula: It is effective because it can omit or simplify the deactivation process of the polymerization catalyst.

In preparing the polyoxymethylene polymer of the present invention, it is effective that the polymerization catalyst is dissolved and added to an organic solvent to induce the polymerization reaction uniformly to produce a uniform polyoxymethylene polymer.

The organic solvent is ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl butyl ether, triethylene glycol butyl ether, One kind or two or more kinds may be selected from the group consisting of propylene glycol dimethyl ether and dipropylene glycol dimethyl ether.

The content of the polymerization catalyst according to the present invention is preferably contained 0.03 to 200ppm, more preferably 0.1 to 100ppm relative to the total monomer content. If the content of the polymerization catalyst is less than 0.03ppm, the polymerization reaction may not occur sufficiently, and the reaction rate may be significantly slowed to increase the manufacturing cost. If the content is more than 200ppm, the reaction rate may be increased and polyoxy having an unstable portion. The methylene polymer may be formed, the content of the polymerization catalyst to be inactivated increases, the content of the polymerization terminator increases, and thus the production cost may increase.

[Formula 2]

[Formula 3]

(In Formula 3, X ₁ and X ₂ are each independently hydrogen or (C 1 -C 6) alkyl, not hydrogen at the same time, x is an integer selected from 2 to 6,

N in Formula 2 and m in Formula 3 are integers selected from 1 to 200.)

The polyoxymethylene polymer is not particularly limited, but may have a weight average molecular weight of 10,000 to 200,000 g / mol.

The oxymethylene homopolymer may be prepared by polymerizing formaldehyde or a cyclic oligomer thereof, that is, trioxane, and the oxymethylene copolymer in which the unit of Formula 2 and the unit of Formula 3 are combined with formaldehyde or a cyclic oligomer thereof. It can be obtained by random copolymerization of the cyclic ether represented by the following formula (5) or the cyclic formal represented by the following formula (6):

[Formula 5]

[Formula 6]

In Chemical Formulas 5 and 6,

X ₃ , X ₄ , X ₅ and X ₆ are each independently hydrogen or (C 1 -C 6) alkyl and may be bonded to the same carbon atom or to other carbon atoms, and at the same time not hydrogen, n and m are Each is an integer selected from 2 to 6.

Among the comonomers used in the random copolymerization, cyclic ethers include ethylene oxide, propylene oxide, butylene oxide, phenylene oxide, and the like, and cyclic formales include 1,3-dioxolane, diethylene glycol formal, 1 , 3-propanediol formal, 1,4-butanediol formal, 1,3-dioxepan formal, 1,3,6-trioxokan etc. are mentioned. Preferably, one or two or more monomers selected from monomers such as ethylene oxide, 1,3-dioxolane and 1,4-butanediol formal can be used.

Oxymethylene copolymers can be obtained by adding these monomers to trioxane or formaldehyde as main monomers and random copolymerization using Lewis acid as a catalyst, whereby the copolymer obtained has a melting point of at least 150 ° C. and at least two in the main chain. It has a bonding carbon atom.

In the oxymethylene copolymer, the ratio of the oxymethylene bond structure to the oxymethylene repeating unit is in the range of 0.05 to 50 mole times, preferably in the range of 0.1 to 20 mole times.

The polymerization method for preparing the polyoxymethylene polymer may be carried out in the form of bulk polymerization, suspension polymerization or solution polymerization, and is not limited as long as it is a polymerization method for producing polyoxymethylene polymer that is known in the art.

It is preferable that the temperature at the time of a polymerization reaction is 0-100 degreeC, It is effective to carry out at 20-80 degreeC more preferably.

If the polymerization temperature is less than 0 ℃ may cause a problem that the polymerization reaction does not occur, if the temperature is higher than 100 ℃ may cause a problem that the reaction rate is too fast to form a uniform polyoxymethylene polymer, the temperature of the above range The polymerization reaction at can control the reaction rate properly and can also help to effectively deactivate the polymerization catalyst.

In addition, in the polymerization reaction of polyoxymethylene, an alkyl substituted phenol or an ether may be used as a chain transferring agent, and particularly preferably, an alkyl ether such as dimethoxymethane may be used.

In order to stop the polymerization reaction of polyoxymethylene, the carbodiimide type polymerization terminator represented by following formula (4) can be added.

[Formula 4]

(In Formula 4, R ₁ and R ₂ are each independently (C1-C20) alkyl, (C6-C20) aryl, (C1-C20) alkoxy, (C3-C20) cycloalkyl, (C2-C7) alkenyl , (C3-C20) heterocycloalkyl, (C4-C20) heteroaryl,

Alkyl, aryl, alkoxy, cycloalkyl, alkenyl, heterocycloalkyl, and heteroaryl of R ₁ and R ₂ may be further substituted with one or more selected from (C1-C7) alkyl, halogen, nitro, cyano, and amino. There is,

Provided that at least one of R ₁ and R ₂ is a cyclic substituent selected from (C3-C20) cycloalkyl, (C6-C20) aryl, (C3-C20) heterocycloalkyl, and (C4-C20) heteroaryl Includes.)

Formula 4 may be one or two or more selected from the following formula 4-1 and 4-2.

[Formula 4-1]

(N in Formula 4-1 is an integer selected from 50 to 200.)

[Formula 4-2]

The content of the polymerization terminator according to the present invention is preferably contained 10 to 5000ppm, more preferably 50 to 1000ppm relative to the content of the total monomer. When the content of the polymerization terminator is less than 10ppm, the deactivation effect on the polymerization catalyst may be reduced, which may cause a problem of lowering the thermal stability. When the content of the polymerization terminator is more than 5000ppm, the content of the low molecular weight polymer is increased to increase the physical properties of the polyoxymethylene polymer. It may be reduced or cause discoloration of the polymer, so it is effective to use it in the above-mentioned range.

The carbodiimide polymerization terminator according to the present invention may be added in the form as it is, or may be dissolved in an organic solvent and added.

Organic solvents that can dissolve the carbonimide-based polymerization terminator include aromatic hydrocarbons such as benzene, toluene, xylene, aliphatic hydrocarbons such as n-hexane, n-heptane, cyclohexane, alcohols such as methanol, chloroform and dichloromethane And organic solvents capable of dissolving carbodiimide polymerization terminators such as halogenated hydrocarbons such as 1,2-dichloroethane and ketones such as acetone and methyl ethyl ketone.

Alkyl as described in the present invention. Substituents comprising alkoxy and other alkyl include both straight chain or branched forms, alkenyl includes both straight chain or branched forms having 2 to 8 carbon atoms and containing one or more double bonds.

The (C3-C20) cycloalkyl described in the present invention includes both saturated monocyclic or saturated bicyclic ring structures having 3 to 20 carbon atoms.

The aryls described in the present invention are organic radicals derived from aromatic hydrocarbons by one hydrogen removal, each containing a single or fused ring system containing 4 to 7 ring atoms, preferably 5 to 6 ring atoms, suitably for each ring. do. Specific examples include, but are not limited to, phenyl, naphthyl, biphenyl, tolyl, and the like.

Heterocycloalkyl described in the present invention is a cycloalkyl group containing 1 to 3 heteroatoms selected from N, O and S as saturated cyclic hydrocarbon backbone atoms, and the remaining saturated monocyclic or bicyclic ring backbone atoms are carbon. Means, pyrrolidinyl, azetidinyl, pyrazolidinyl, oxazolidinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, thiazolidinyl, hydantoinyl, valerolactamyl , Oxiranyl, oxetanyl, dioxolanyl, dioxanyl, oxathiolanyl, oxathanyl, ditianyl, dihydrofuranyl, tetrahydrofuranyl, dihydropyranyl, tetrahydropyranyl, tetrahydro Pyridinyl, tetrahydropyrimidinyl, tetrahydrothiophenyl, tetrahydrothiopyranyl, diazepanyl and azepanyl.

Heteroaryl described in the present invention means an aryl group containing 1 to 3 heteroatoms selected from N, O, and S as an aromatic ring skeleton atom, and the remaining aromatic ring skeleton atoms are carbons. Heteroatoms include divalent aryl groups that are oxidized or quaternized to form, for example, N-oxides or quaternary salts. Specific examples include furyl, thiophenyl, pyrrolyl, pyranyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isosazolyl, oxazolyl, oxdiazolyl, triazinyl, tetrazinyl, tria Zolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl and the like.

By adding a polymerization catalyst and a polymerization terminator of the present invention to prepare a polyoxymethylene polymer, it is possible to form a polyoxymethylene polymer having a uniform molecular weight distribution and other physical properties, which can omit or simplify the deactivation process, and after polymerization It is possible to effectively deactivate the polymerization catalyst to suppress depolymerization, thereby producing a polyoxymethylene polymer having a low molecular weight content and excellent thermal stability.

The terminal Formate content of the polyoxymethylene polymer prepared by the production method of the present invention is 3.0 to 8.0μmol / g-POM, it can be seen that formaldehyde emission is significantly reduced to 50 to 200ppm.

Hereinafter, a method for preparing a polyoxymethylene polymer of the present invention and a polyoxymethylene polymer prepared therefrom will be described in detail through Examples and Comparative Examples.

Property measurement

1. Melt Index (MI)

The weight of the polyoxymethylene polymer sample extruded at a temperature of 190 ° C. and a load of 2.16 kg for 10 minutes at an orifice of constant internal diameter was measured. This value is a measure for evaluating the depolymerization rate of the polymer. Higher values indicate higher depolymerization rates.

2. Terminal Formate Content Measurement

The polyoxymethylene polymer of the present invention was prepared in the form of a film and immersed in a chloroform solution at 100 ° C. for 6 hours, and then measured the area of 1778˜1697 cm ⁻¹ area using FT-IR (Perkin Elmer Spectrum 2000). The formate group is a representative unstable terminal of the polyoxymethylene polymer, and the higher the value, the easier the depolymerization and the poor the thermal stability.

3. Formaldehyde generation amount measurement (HS-GC method)

3g of the polyoxymethylene polymer sample pellet of the present invention is quantitatively analyzed for formaldehyde gas generated after 1 hour residence at 185 ° C using Headspace GC (7890A, Agilent). The higher the value, the worse the thermal stability.

4. Acetic acid resistance measurement

Emission amount of formaldehyde using UV / VIS (Perkin-Elmer, Inc.) was extracted from the polyoxymethylene polymer of the present invention by making a test piece having a surface area of 100 cm ² and immersing it in 3 wt% acetic acid solution at 40 ° C. for 10 days. Qualitative analysis This value represents the degree of depolymerization of the polyoxymethylene polymer by acetic acid, and the higher the value, the higher the degree of depolymerization.

Example 1

After maintaining a 600cc polymerizer at 50 ° C, 500 g of trioxane and 20 g of 1,3-dioxolane were injected into a comonomer using a metering device, followed by 0.0015 g of trimethylsilyl trifluoromethanesulfonate (TMST) as a polymerization catalyst. Dilution with 3 ppm per trioxane) was added. After 10 minutes after the addition of the polymerization catalyst, PCDI (Poly- (1,3,5-triisopropyl-phenylene-2,4-carbodiimide, Mw: 20,000)) was converted to 100 ppm (benzene) with respect to the polyoxymethylene copolymer. 10 minutes after the completion of the reaction, the resultant polymer was obtained, and the above-described melt index, terminal Formate content, formaldehyde generation rate, and acid resistance were measured for the resulting polyoxymethylene polymer. Table 2 shows.

[Examples 2 to 11]

As shown in Table 1, the polyoxymethylene polymer was obtained in the same manner as in Example 1 except that the solvent and content of the polymerization catalyst and the type and content of the polymerization terminator were changed. For the produced polyoxymethylene polymer, the melt index, the terminal Formate content, the amount of formaldehyde generated, and the acid resistance of the above-described polymers were measured and the results are shown in Table 2.

Comparative Example 1

As shown in Table 1 below, Boron trifluoride diethyl etherate was dissolved in benzene as a polymerization catalyst and contained 70 ppm of trioxane, except that 500 ppm of TPP (Triphenylphosphine) was added to the polyoxymethylene copolymer as a polymerization terminator. In the same manner as in Example 1, a polyoxymethylene polymer was obtained. For the produced polyoxymethylene polymer, the melt index, the terminal Formate content, the amount of formaldehyde generated, and the acid resistance of the above-described polymers were measured and the results are shown in Table 2.

Comparative Example 2

As shown in Table 1, TIN 765 (Bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate + methyl 1,2,2,6,6-pentamethyl-4-piperidyl as a polymerization terminator sebacate) Except that the addition of 3000ppm was carried out in the same manner as in Example 1 to obtain a polyoxymethylene polymer. For the produced polyoxymethylene polymer, the melt index, the terminal Formate content, the amount of formaldehyde generated, and the acid resistance of the above-described polymers were measured and the results are shown in Table 2.

[Comparative Examples 3-4]

As shown in Table 1, except that the content of the polymerization catalyst was changed, the same procedure as in Example 1 to obtain a polyoxymethylene polymer. For the produced polyoxymethylene polymer, the melt index, the terminal Formate content, the amount of formaldehyde generated, and the acid resistance of the above-described polymers were measured and the results are shown in Table 2.

TABLE 1

TABLE 2

As shown in Table 2, Comparative Examples 1 to 4 can be seen that the melt index, the terminal Formate content, formaldehyde emission amount and Acetic acid resistance is significantly lower than that of Examples 1 to 10.

Therefore, the polyoxymethylene polymers of Examples 1 to 10 of the present invention can polymerize a polyoxymethylene polymer having sufficient physical properties even with a small amount of a novel polymerization catalyst, and use a polymerization terminator suitable for such a polymerization catalyst. By doing so, it can be seen that the polymerization catalyst can be effectively deactivated, and the unstable portion can be significantly reduced to significantly improve durability and heat resistance.

Although the preferred embodiment of the present invention has been described above, it is clear that the present invention can use various changes and equivalents, and can be applied in the same manner by appropriately modifying the above embodiment. Accordingly, the above description is not intended to limit the scope of the invention as defined by the following claims.

Claims (9)

1. The oxymethylene homopolymer composed of the repeating unit represented by the following formula (2) or the repeating unit represented by the following formula (2) and the following formula (3) using a polymerization catalyst represented by the following formula (1) and a carbodiimide-based polymerization terminator Method of producing a polyoxymethylene polymer for producing an oxymethylene copolymer bonded randomly repeating units.

   [Formula 1]

   

   (In Formula 1, X is nitrogen or oxygen, Y is SiR ₁ R ₂ R ₃ , n is 1 or 2.)

   [Formula 2]

   

   [Formula 3]

   

   (In Formula 3, X ₁ and X ₂ are each independently hydrogen or (C 1 -C 6) alkyl, not hydrogen at the same time, x is an integer selected from 2 to 6,

   N in Formula 2 and m in Formula 3 are integers selected from 1 to 200.)
2. The method of claim 1,

   The carbodiimide-based polymerization terminator is a method for producing a polyoxymethylene polymer is a compound represented by the following formula (4)

   [Formula 4]

   

   (In Formula 4, R ₁ and R ₂ are each independently (C1-C20) alkyl, (C6-C20) aryl, (C1-C20) alkoxy, (C3-C20) cycloalkyl, (C2-C7) alkenyl , (C3-C20) heterocycloalkyl, (C4-C20) heteroaryl,

   Alkyl, aryl, alkoxy, cycloalkyl, alkenyl, heterocycloalkyl, and heteroaryl of R ₁ and R ₂ may be further substituted with one or more selected from (C1-C7) alkyl, halogen, nitro, cyano, and amino. There is,

   Provided that at least one of R ₁ and R ₂ is a cyclic substituent selected from (C3-C20) cycloalkyl, (C6-C20) aryl, (C3-C20) heterocycloalkyl, and (C4-C20) heteroaryl Includes.)
3. The method of claim 1,

   The polymerization catalyst of Formula 1 is a method for producing a polyoxymethylene polymer is selected from the following formula

   
4. The method of claim 2,

   The carbodiimide-based polymerization terminator is a method for producing a polyoxymethylene polymer is one or two or more selected from formulas (4-1) and (4-2).

   [Formula 4-1]

   

   (N in Formula 4-1 is an integer selected from 50 to 200.)

   [Formula 4-2]

   
5. The method of claim 1,

   The content of the polymerization catalyst is included 0.03 to 200ppm relative to the total monomer content,

   The content of the polymerization terminator is a method for producing a polyoxymethylene polymer containing 10 to 5000ppm relative to the total monomer content.
6. The method of claim 1,

   The polymerization catalyst is a method for producing a polyoxymethylene polymer dissolved in an organic solvent and added.
7. The method of claim 6,

   The organic solvent may be ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl butyl ether, triethylene glycol butyl ether, A method for producing a polyoxymethylene polymer, which is one or two or more organic solvents selected from the group consisting of propylene glycol dimethyl ether and dipropylene glycol dimethyl ether.
8. A polyoxymethylene polymer prepared by the method of any one of claims 1 to 7.
9. The method of claim 8,

   The terminal Formate content of the polyoxymethylene polymer is 3.0 to 8.0 μmol / g-POM, formaldehyde emission amount is 50 to 200 ppm polyoxymethylene polymer.