Polyacetal resin composition

Abstract

To provide a polyacetal resin composition which can reduce formaldehyde gas emissions in the course of production and molding and from the resin product, which is free from mold deposits during molding, and which prevents additive bleed-out from the resin product.SOLUTION: A polyacetal resin composition of the present invention comprises a compound having at least one structure represented by the following formula (1), and a polyacetal resin. (In formula (1), *1 to *4 represent bonding sites).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a polyacetal resin composition. [Background technology]

[0002] Polyacetal resin is a material with excellent rigidity, strength, toughness, sliding properties and creep resistance. It is used in a wide range of applications as a resin material for various mechanical parts such as automobile parts, electrical and electronic parts and industrial parts.

[0003] Polyacetal resin generates formaldehyde when it decomposes. In particular, there are concerns that formaldehyde gas generated by thermal decomposition during manufacturing and molding processes can worsen the working environment, and that formaldehyde gas generated from resin products can worsen the indoor environment.

[0004] As a method for suppressing the generation of formaldehyde from polyacetal resin, a method of adding a formaldehyde-reactive substance is known. Since polyacetal resin is easily decomposed by the action of acid or alkali, a formaldehyde scavenger that has the effect of suppressing the emission of formaldehyde without decomposing polyacetal resin is required.

[0005] In addition, polyacetal resin is highly crystalline and therefore difficult to mix with other substances. In order to stabilize the performance of polyacetal resin over a long period of time, it is important to select additives that are compatible with polyacetal resin and do not bleed out or aggregate in the usage environment.

[0006] For example, when a large amount of conventionally known formaldehyde-reactive substances such as hydrazide, guanamine, urea, and amide is added, mold deposits may occur during molding processing or bleed out under high temperature and humidity conditions, and there are cases in which the generation of formaldehyde cannot be sufficiently suppressed. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in view of the above circumstances, and has an object to provide a polyacetal resin composition that can suppress formaldehyde gas emission during production, molding, and from resin products, does not cause mold deposits during molding, and does not cause bleed-out of additives from resin products. [Means for solving the problem]

[0008] As a result of intensive research by the present inventors, they have found that adding a compound having a structure represented by the following formula (1) to a polyacetal resin effectively captures formaldehyde generated from the polyacetal resin, thereby reducing the amount of formaldehyde gas generated during production, molding, and from resin products, and that the compound having the above structure has good compatibility with polyacetal resin and is less likely to cause mold deposits or bleed-out, thereby completing the present invention. That is, the present invention is as follows.

[0009] [1] A polyacetal resin composition comprising a compound having at least one structure represented by the following formula (1) and a polyacetal resin: [ka] (In formula (1), *1 to *4 represent bonds.) [2] The polyacetal resin composition according to [1], comprising 0.01 to 100 mmol of the compound per 100 g of the polyacetal resin. [3] The compound is A part or all of the structure contained in the compound is Any two of *1 to *4 in the structure are bonded directly or via a linking moiety to form a ring structure. The polyacetal resin composition according to [1] or [2]. [4] The compound is A part or all of the structure contained in the compound is In the structure, *3 and *4 are bonded directly or via a linking moiety to form a ring structure, and the linking moiety is an optionally substituted alkylene group or heteroalkylene group. The polyacetal resin composition according to [1] or [2]. [5] The compound is A part or all of the structure contained in the compound is The *3 and *4 in the structure are bonded directly or via a linking moiety to form a ring structure, the linking moiety is an optionally substituted alkylene group or heteroalkylene group, and at least one of the *1 and *2 in the structure is a hydrogen atom. The polyacetal resin composition according to [1] or [2]. [6] The compound is having one of the above structures, The *1 and *2 are each independently a hydrogen atom, an alkyl group, a halogenated alkyl group, an aryl group, or an ester group, The *3 is a hydrogen atom, an alkyl group, a halogenated alkyl group, a thioalkyl group, an ether group, or an alkoxy group, The *4 is a hydrogen atom, an alkyl group, a thioalkyl group, an aryl group, a heteroaryl group, an amino group, an aminoalkyl group, an ether group, or an alkoxy group. The polyacetal resin composition according to claim 1 or 2. [7] The polyacetal resin composition according to [6], wherein at least one of *1 and *2 in the structure is a hydrogen atom. [8] The compound is The polyacetal resin composition according to [1] or [2], which has two or more of the above structures, and any of *1 to *4 in the different structures is bonded directly or via a linking portion. [9] The compound is It has two or more of the above structures, and the *4 in the different structures are bonded to each other via a linking portion, and the linking portion is a structure consisting of at least one selected from the group consisting of an optionally substituted ether group, a thioether group, an ester group, and an alkylene group. The polyacetal resin composition according to [1] or [2].

[10] The compound is It has two or more of the above structures, the *4 in different structures are bonded to each other via a linking moiety, and the linking moiety is a structure consisting of at least one selected from the group consisting of an optionally substituted ether group, a thioether group, an ester group, and an alkylene group, The above *1 and *2 are each independently a hydrogen atom, an alkyl group, a halogenated alkyl group, an aryl group, or an ester group. The above *3 is a hydrogen atom, an optionally substituted alkyl group, a halogenated alkyl group, a thioalkyl group, or an alkoxy group. The polyacetal resin composition according to [1] or [2],

[11] The polyacetal resin composition according to [1] or [2], except for the case where the compound is a compound in which all of the structures contained in the compound are compounds in which the nitrogen atom in formula (1) and the carbon atom at the alpha position of the carbonyl group form a 6-membered aromatic ring.

[12] The polyacetal resin composition according to [1] or [2], except when the compound is uracil.

[13] A method for suppressing formaldehyde emission from a polyacetal resin, comprising mixing a compound having at least one structure represented by the following formula (1) with the polyacetal resin. [ka] (In formula (1), *1 to *4 represent bonds.)

[14] A use of a compound having at least one structure represented by the following formula (1) for suppressing formaldehyde emission from a polyacetal resin. [ka] (In formula (1), *1 to *4 represent bonds.) Effect of the Invention

[0010] Since the polyacetal resin composition of the present invention has the above-mentioned constitution, it is possible to suppress formaldehyde gas during production, etc., and also to prevent mold deposits from being generated during molding processing, and additives from bleeding out from resin products. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment for carrying out the present invention (hereinafter, referred to as "the present embodiment") will be described in detail. Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to the embodiment. In other words, the present invention can be modified in various ways without departing from the gist of the present invention.

[0012] [Polyacetal resin composition] The polyacetal resin composition of the present embodiment contains a compound having at least one structure represented by the following formula (1) and a polyacetal resin. [ka] (In formula (1), *1 to *4 represent bonds.) The polyacetal resin composition of the present embodiment may be a composition consisting of only the above compound and the above polyacetal resin, or may further contain other components. In this specification, a compound having at least one structure represented by formula (1) may be simply referred to as a "compound." Also, a structure represented by formula (1) may be simply referred to as a "structure."

[0013] The above structure may be in the E form or in the Z form. [ka] When a plurality of the above structures are contained, all may be either E- or Z-isomers, or both E- and Z-isomers may be contained.

[0014] When two of the above structures are included, they may be symmetrical or asymmetrical. [ka] [ka]

[0015] In the above structure, *1 to *4 may be bonded to each other to form a ring. [ka] When a plurality of the above structures are contained, any of *1 to *4 in different above structures may be bonded to each other to form a ring.

[0016] <Compound> The number of the above structures contained in the above compound may be 1, 2, 3, 4, or 5. Among them, from the viewpoint of further suppressing formaldehyde emission, it is preferable that the number is 2 or less, and more preferably 1. The above structures contained in the above compounds may be the same structure or different structures.

[0017] Examples of *1 and *2 above include a hydrogen atom, an alkyl group, a halogenated alkyl group, an aryl group, an ester group, and the like. The alkyl group may be an alkyl group having 1 to 10 carbon atoms, such as a methyl group or an ethyl group (preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 2 carbon atoms). The alkyl group may be linear or branched. The halogenated alkyl group may be a chloroethyl alkyl group. Examples of the aryl group include a phenyl group, a phenylmethyl group, a dichlorophenyl group, a 2-chloro-5-nitrophenyl group, a naphthyl group, an anthryl group, a phenanthryl group, and a pyrenyl group. Examples of the ester group include a 2-methyl-1-oxopropyl group and a 1,1-dimethylethylaminocarbonyl group.

[0018] The above *3 includes a hydrogen atom, an optionally substituted alkyl group, a halogenated alkyl group, a thioalkyl group, an ether group (for example, a monovalent group containing an ether group such as an alkyl ether group), an alkoxy group, and the like. Examples of the alkyl group include an alkyl group having 1 to 10 carbon atoms, such as a methyl group or an ethyl group (preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 2 carbon atoms). The alkyl group may be linear or branched. The alkyl group may be substituted to have an ether structure or an ester structure. For example, the alkyl group may have an ester structure, such as 1,5-Dimethyl 3-[(2-chloroethyl)amino]-2-pentendioate, or an ether structure, such as Ethyl 3-amino-4-[2-(1,3dihydro-1,3-dioxo-2H-isoindol-2-yl)ethoxy]-2-butenoate. Examples of the halogen in the halogenated alkyl group include fluorine, chlorine, bromine, and iodine, with fluorine and bromine being preferred, and examples of the alkyl group include linear or branched alkyl groups having 1 to 10 carbon atoms, such as methyl and ethyl groups (preferably alkyl groups having 1 to 5 carbon atoms, and more preferably alkyl groups having 1 to 2 carbon atoms), etc. Among these, a trifluoromethyl group is preferred. The thioalkyl group may have 1-10 carbon atoms, or may have 1-5 carbon atoms. The alkoxy group may have a structure in which an alkyl group having 1 to 10 carbon atoms (preferably an alkyl group having 1 to 5 carbon atoms) is bonded to an oxygen atom.

[0019] Examples of the above *4 include a hydrogen atom, an alkyl group, a thioalkyl group, an optionally substituted aryl group, a heteroaryl group, an amino group, an aminoalkyl group, an ether group (for example, a monovalent group containing an ether group such as an alkyl ether group), an optionally substituted alkoxy group, and the like. The alkyl group may be an alkyl group having 1 to 10 carbon atoms (preferably an alkyl group having 1 to 5 carbon atoms), such as a methyl group or an ethyl group. The alkyl group may be linear or branched. The thioalkyl group may have 1-10 carbon atoms, or may have 1-5 carbon atoms. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group, etc. The aryl group may be substituted, such as N-[3-[3-(Dimethylamino)-1-oxo-2-propenyl]phenyl]-N-methylacetamide, N-[3-[3-(Dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide, and N-[3-[3-(Dimethylamino)-1-oxo-2-propen-1-yl]phenyl]acetamide. Examples of the heteroaryl group include those having a heteroatom (eg, oxygen atom, nitrogen atom, sulfur atom, etc.) between the carbon atoms of the aryl group, such as a pyridiyl group or a thienyl group. The aminoalkyl group may have 1-10 carbon atoms, or may have 1-5 carbon atoms. The alkoxy group may be a structure in which an alkyl group having 1 to 20 carbon atoms (preferably an alkyl group having 1 to 10 carbon atoms) is bonded to an oxygen atom. The alkoxy group may be substituted to have an ether structure such as 2-butenoic acid, 3-amino, 2-methoxyethyl ester, a hydroxyl group such as 4-hydroxybutyl 3-amino-2-butenoate, or a substituted amino group such as 2-[Methyl(phenylmethyl)amino]ethyl 3-amino-2-butenoate or 2-[4-(Diphenylmethyl)-1-piperazinyl]ethyl 3-amino-2-butenoate.

[0020] As the above compound, 3-(Dimethylamino)-2-propenal, 4-Amino-3-penten-2-one, Methyl 3-amino-2-butenoate, 2-Butenoic acid,3-amino-, ethyl ester, 3-Amino-2-butenamide, Ethyl 3-(dimethylamino)acrylate, 2-Butenoic acid, 3-amino-, 1-methylethyl ester, Ethyl 3-(ethylamino)-2-propenoate, 2-Butenoic acid, 3-amino-, 2-methoxyethyl ester, 4-Hydroxybutyl 3-amino-2-butenoate, 3-(Methylphenylamino)-2-propenal, 2-Butenoic acid, 3-amino-, 2-methylpropyl ester, Ethyl 3-(dimethylamino)-2-butenoate, Tetradecyl 3-amino-2-butenoate, 3-Dimethylamino-1-(3-pyridyl)-2-propen-1-one, Hexadecyl 3-amino-2-butenoate, Octadecyl 3-amino-2-butenoate, N-Methyl-3-(methylamino)-2-butenamide, 3-Dimethylamino-1-(2-pyridyl)prop-2-en-1-one, 3-(Dimethylamino)-1-(2-thienyl)-2-propen-1-one, Ethyl 3-amino-4,4,4-trifluoro-2-butenoate, 2-Butenoic acid, 4,4,4-trifluoro-3-(methylamino)-, ethyl ester, Ethyl 3-(phenylamino)-2-butenoate, 1,5-Dimethyl 3-[(2-chloroethyl)amino]-2-pentenedioate, 2-[Methyl(phenylmethyl)amino]ethyl 3-amino-2-butenoate, 3-[(2-Methyl-1-oxopropyl)amino]-2-butenamide, Propanoic acid, 3-ethoxy-3-imino-, ethyl ester, Methyl 3-[[[(1,1-dimethylethyl)amino]carbonyl]amino]-2-butenoate, N-[3-[3-(Dimethylamino)-1-oxo-2-propenyl]phenyl]-N-methylacetamide, N-[3-[3-(Dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide, N-[3-[3-(Dimethylamino)-1-oxo-2-propen-1-yl]phenyl]acetamide, Phenyl 3-ethoxy-3-iminopropanoate, Ethyl 3-[(2-chloro-5-nitrophenyl)amino]-3-ethoxy-2-propenoate, 2-[4-(Diphenylmethyl)-1-piperazinyl]ethyl 3-amino-2-butenoate, Ethyl 3-amino-4-[2-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)ethoxy]-2-butenoate, etc. compounds whose above structures do not form a ring structure; 4-(1-Pyrrolidinyl)-3-buten-2-one, 4-(1-Pyrrolidinyl)-3-penten-2-one, 4-Methyl-1-(4-morpholinyl)-1-penten-3-one, 2-(Formylmethylene)-1,3,3-trimethylindoline, Ethyl 2-(3-ethyl-4-oxo-2-thiazolidinylidene)acetate, 1-(3-Ethyl-2(3H)-benzothiazolylidene)-2-propanone, 1,Compounds in which the above structures such as 2-Dihydro-2-phenyl-3H-pyrazol-3-one, 2-(3-Methyl-2(3H)-benzothiazolylidene)-1-phenylethanone, 3-Amino-2-cyclohexen-1-one, 3-Amino-5-methyl-2-cyclohexen-1-one, 3-amino-5,5-dimethyl-2-cyclohexen-1-one, 3-(Dimethylamino)-2-cyclohexen-1-one, 3-(Dimethylamino)-5,5-dimethyl-2-cyclohexen-1-one, 5-Amino-2H-pyran-3(6H)-one, 3-Amino-cyclopenten-1-one, 2,3-Dihydro-4(1H)-pyridinone, 4-Amino-5-methyl-2(1H)-pyridinone, Uracil, etc. form a ring structure; 2-Butenoic acid, 3-amino-, 1,2-ethanediyl ester, 2-Butenoic acid, 3-amino-, 1,1’-(1,4-butanediyl) ester, 2-Butenoic acid, 3-amino-, 1-methyl-1,3-propanediyl ester, 2-Butenoic acid, 3-amino-, 1,1’-(thiodi-2,1-ethanediyl) ester, 2-Butenoic acid, 3-amino-, oxybis(1-methyl-2,1-ethanediyl) ester, N,N’-1,6-Hexanediylbis[3-amino-2-butenamide], 4-([3-[(3-Oxobut-1-en-1-yl)amino]propyl]amino)but-3-en-2-one, 4,4‘-(1,2-Ethanediyldiimino)bis[3-penten-2-one], 4,4’-(1,6-Hexanediyldiimino)bis[3-penten-2-one], 4,4‘-[(1-Methyl-1,2-ethanediyl)diimino]bis[3-penten-2-one], 2,12-Diamino-2,Examples of compounds having multiple of the above structures include 11-tridecadiene-4,10-dione, 1,6-Diamino-1,6-diethoxy-1,5-hexadiene-3,4-dione, 4-Amino-2-oxo-3-penten-1-yl 5-amino-3-oxo-4-hexenoate, 2-Butenoic acid, 3-amino-, 1-ethyl-1,2-ethanediyl ester, and 2-Butenoic acid, 3-amino-, 1,1'-(1,4-butanediyl) ester. Examples of the compound in which the above structure does not form a ring structure include the compound (b) described below. Examples of the compound in which the above structure forms a ring structure include the compound (a) described below. An example of a compound having a plurality of the above structures is the compound (c) described below.

[0021] From the viewpoint of further suppressing formaldehyde emission, the compound in which the structure forms a ring structure is preferable. Among them, from the viewpoint of being particularly excellent in suppressing formaldehyde emission, the compound in which the structure forms a ring structure in which *1 and *2 are both hydrogen atoms is preferable, and 3-Amino-2-cyclohexen-1-one, 3-Amino-5-methyl-2-cyclohexen-1-one, and 3-Amino-5,5-dimethyl-2-cyclohexen-1-one are more preferable.

[0022] In compounds in which the above structure does not form a ring structure, from the viewpoint of suppressing formaldehyde emission, compounds having the above structure in which either *1 or *2 is a hydrogen atom are preferred, and compounds in which both *1 and *2 are hydrogen atoms are more preferred.

[0023] The compound is preferably a compound having a plurality of the above structures, from the viewpoint of being able to suppress bleeding out even under high temperature and high humidity conditions.

[0024] The above compounds include (a) A compound in which a part or all of the above structures contained in the compound are such that any two of the above *1 to *4 in one and the same structure are bonded to each other directly or via a linking portion to form a ring structure, (b) A compound having one of the above structures, in which *1 and *2 are each independently a hydrogen atom, an alkyl group, a halogenated alkyl group, an aryl group, or an ester group functional group, *3 is a hydrogen atom, an alkyl group, a halogenated alkyl group, a thioalkyl group, an ether group (e.g., a monovalent group containing an ether group such as an alkyl ether group), or an alkoxy group, and *4 is a hydrogen atom, an alkyl group, a thioalkyl group, an aryl group, a heteroaryl group, an amino group, an aminoalkyl group, an ether group (e.g., a monovalent group containing an ether group such as an alkyl ether group), or an alkoxy group, (c) A compound having two or more of the above structures, in which any of *1 to *4 in different above structures is bonded directly or via a linking portion. is preferred. In this specification, the above compounds (a), (b), and (c) may be referred to as compound (a), compound (b), and compound (c), respectively.

[0025] (Compound (a)) The compound (a) preferably has one of the above structures.

[0026] In the compound (a), any two of the above *1 to *4 in one of the above structures are bonded to each other directly or via a linking portion to form a ring structure, and it is preferable that *1 or *2 and *4 form a ring structure, or *3 and *4 form a ring structure. It is more preferable that *3 and *4 form a ring structure. The number of the ring structure is preferably one.

[0027] The ring structure of the compound (a) is preferably formed via a linking group. Examples of the linking group include an optionally substituted alkylene group (e.g., an alkylene group having 1 to 10 carbon atoms) and a heteroalkyl group (e.g., an alkoxyl group having 1 to 10 carbon atoms and containing a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom between bonds, which may be substituted with a substituent such as an amino group). The alkylene group may be linear or branched. Here, examples of the substituent include an alkyl group having 1 to 10 carbon atoms.

[0028] The ring structure may be a ring structure in which the above *3 and the above *4 are linked via a linking group. In this case, the linking group is preferably a linear or branched alkylene group having 2 to 5 carbon atoms, or a heteroalkylene group in which one carbon atom of an alkylene group having 2 to 5 carbon atoms is replaced with a heteroatom, and more preferably a linear or branched alkylene group having 2 to 5 carbon atoms.

[0029] The ring structure may be a ring structure in which the above *1 or the above *2 and the above *4 are bonded via a linking group, and in this case, the linking group is preferably a linear alkylene group having 2 to 5 carbon atoms.

[0030] In the compound (a), it is preferable that at least one of the *1 to the *2 that do not form a ring structure is a hydrogen atom, and it is more preferable that all of the *1 to the *2 that do not form a ring structure are hydrogen atoms.

[0031] (Compound (b)) The compound (b) has one of the above structures. It is preferable that the compound (b) does not have a ring structure in which any two of the above *1 to *4 are bonded to each other directly or via a linking portion.

[0032] In the compound (b), the above *1 and *2 may be the same or different. Among them, it is preferable that they are the same from the viewpoint of further suppressing the generation of formaldehyde gas.

[0033] In the compound (b), it is preferable that the *1 and *2 are a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a phenyl group. From the viewpoint of further suppressing the generation of formaldehyde gas, it is preferable that at least one of the *1 and *2 is a hydrogen atom, and it is more preferable that the *1 and *2 are both hydrogen atoms.

[0034] In the compound (b), the above *3 is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 5 carbon atoms from the viewpoint of further suppressing the generation of formaldehyde gas.

[0035] In the compound (b), the above *4 is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a heteroaryl group having a nitrogen atom and having 5 to 8 carbon atoms, an amino group, or an alkoxy group having 1 to 5 carbon atoms.

[0036] From the viewpoint that excellent effects can be obtained even with a small amount of addition, the above compound (b) is preferably a compound in which the above *1 and the above *2 are both hydrogen atoms, the above *3 is an alkyl group having 1 to 5 carbon atoms (preferably an alkyl group having 1 to 2 carbon atoms), and the above *4 is an alkoxy group having 1 to 5 carbon atoms (preferably an alkoxy group having 1 to 2 carbon atoms).

[0037] (Compound (c)) The compound (c) preferably has two or more of the above structures, more preferably has two. For example, two of the above structures may be directly bonded, two of the above structures may be bonded via a divalent linking moiety, three of the above structures may be directly bonded, or three of the above structures may be bonded via a trivalent linking moiety. It is preferable that the compound (c) does not have a ring structure (for example, a ring structure in which any two of the above *1 to *4 in one of the above structures are bonded to each other directly or via a linking portion, or a ring structure in which any of the above *1 to *4 in two different structures are bonded to each other directly or via a linking portion).

[0038] From the viewpoint of further suppressing the generation of formaldehyde gas, the compound (c) is preferably such that the *1's, 2's, 3's, and 4's of two different structures are bonded directly or via a linking moiety, and more preferably such that the *4's are bonded directly or via a linking moiety. It is preferable that the *1 to *3 of the two structures are the same.

[0039] The linking portion is preferably an optionally substituted alkylene group (e.g., an alkylene group having 1 to 10 carbon atoms), an ether (-O-), a thioether (-S-), an ester (-C(=O)O-), or a combination thereof. From the viewpoint of further suppressing the generation of formaldehyde gas, it is preferable that the above *4 in the two above structures is bonded to an ether (-O-), and the two ethers are a structure sandwiching only an optionally substituted alkylene group (e.g., an alkylene group having 1 to 10 carbon atoms), a thioether (-S-), or a combination thereof, and it is more preferable that the above *4 in the two above structures is bonded to an ether (-O-), and the two ethers are a structure sandwiching only an optionally substituted alkylene group (e.g., an alkylene group having 1 to 10 carbon atoms). Here, examples of the substituent include an alkyl group having 1 to 10 carbon atoms.

[0040] The *1 and *2 in the above structure of the compound (c) are preferably a hydrogen atom, an alkyl group, a halogenated alkyl group, an aryl group, an ester group, or a combination thereof, more preferably a hydrogen atom, an alkyl group, an aryl group, or an ester group. The *1 and *2 in all of the above structures are preferably a hydrogen atom. The alkyl group may be an alkyl group having 1 to 10 carbon atoms (preferably an alkyl group having 1 to 5 carbon atoms), such as a methyl group or an ethyl group. The alkyl group may be linear or branched. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, and a pyrenyl group. Examples of the ester group include a 2-methyl-1-oxopropyl group and a 1,1-dimethylethylaminocarbonyl group.

[0041] The *3 in the above structure of the compound (c) is preferably a hydrogen atom, an optionally substituted alkyl group, a halogenated alkyl group, a thioalkyl group, an alkoxy group, or a combination thereof, and more preferably a hydrogen atom, an optionally substituted alkyl group, a halogenated alkyl group, a thioalkyl group, or an alkoxy group. The alkyl group may be an alkyl group having 1 to 10 carbon atoms (preferably an alkyl group having 1 to 5 carbon atoms), such as a methyl group or an ethyl group. The alkyl group may be linear or branched. Examples of the halogen in the halogenated alkyl group include fluorine, chlorine, bromine, and iodine, and examples of the alkyl group include linear or branched alkyl groups having 1 to 10 carbon atoms (preferably alkyl groups having 1 to 5 carbon atoms), such as a methyl group or an ethyl group. The thioalkyl group may have 1-10 carbon atoms, or may have 1-5 carbon atoms. The alkoxy group may have a structure in which an alkyl group having 1 to 10 carbon atoms (preferably an alkyl group having 1 to 5 carbon atoms) is bonded to an oxygen atom. The above *3 in the above two structures of the compound (c) is preferably an alkyl group having 1 to 10 carbon atoms (preferably an alkyl group having 1 to 5 carbon atoms), such as a methyl group or an ethyl group. The alkyl group may be linear or branched. Examples of the substituent in the alkyl group, halogenated alkyl group, and thioalkyl group include an alkyl group having 1 to 10 carbon atoms, a hydroxy group, a carboxy group, and a halogen atom.

[0042] From the viewpoint of further suppressing the generation of formaldehyde gas, the above compound is preferably a compound other than uracil, more preferably a compound other than uracil which may be substituted with an alkyl group having 1 to 5 carbon atoms, still more preferably a compound other than a compound in which all of the above structures contained in the above compound are compounds in which the nitrogen atom in formula (1) and the carbon atom at the alpha position of the carbonyl group form a 6-membered aromatic ring, and particularly preferably a compound other than a compound containing the above structure in which the nitrogen atom in formula (1) and the carbon atom at the alpha position of the carbonyl group form a 6-membered aromatic ring.

[0043] <Polyacetal resin> Examples of the polyacetal resin include polyacetal homopolymers and polyacetal copolymers. The polyacetal resins may be used alone or in combination of two or more.

[0044] The polyacetal homopolymer is not particularly limited, but a representative example is one that is obtained by homopolymerizing a formaldehyde monomer or a cyclic oligomer of formaldehyde such as its trimer (trioxane) or tetramer (tetraoxane), and is substantially composed of only oxymethylene units. In addition, the polyacetal homopolymer may also have a block component obtained by polymerizing a formaldehyde monomer or a cyclic oligomer of formaldehyde in the presence of a compound having a functional group such as a hydroxyl group at both or one end, such as polyalkylene glycol.

[0045] The polyacetal copolymer is not particularly limited, but a representative example is one obtained by copolymerizing a cyclic oligomer of formaldehyde, such as a formaldehyde monomer or its trimer (trioxane) or tetramer (tetraoxane), with a cyclic ether and / or cyclic formal, such as ethylene oxide, propylene oxide, epichlorohydrin, 1,3-dioxolane, 1,4-butanediol formal, or a cyclic formal of glycol or diglycol. In addition, the polyacetal copolymer may have a block component obtained by copolymerizing a formaldehyde monomer or a cyclic oligomer of formaldehyde with a cyclic ether and / or cyclic formal in the presence of a compound having a functional group such as a hydroxyl group at both ends or one end, such as hydrogenated polybutadiene glycol. Furthermore, as the polyacetal copolymer, for example, a branched polyacetal copolymer obtained by copolymerizing a monofunctional glycidyl ether, or one having a crosslinked structure obtained by copolymerizing a polyfunctional glycidyl ether can also be used.

[0046] When the polyacetal resin contains a polyacetal copolymer, it is preferable to use trioxane, a formaldehyde trimer, for copolymerization of the polyacetal copolymer.

[0047] As the polymerization catalyst in the polymerization of polyacetal copolymer, it is preferable to use a cationic active catalyst such as Lewis acid, protonic acid, and its ester or anhydride.As Lewis acid, for example, boric acid, tin, titanium, phosphorus, arsenic and antimony halide can be mentioned, specifically, boron trifluoride, tin tetrachloride, titanium tetrachloride, phosphorus pentafluoride, phosphorus pentachloride, antimony pentafluoride and its complex compound or salt can be mentioned.In addition, specific examples of protonic acid, its ester or anhydride can be mentioned perchloric acid, trifluoromethanesulfonic acid, perchloric acid-tertiary butyl ester, acetyl perchlorate, trimethyloxonium hexafluorophosphate, etc.

[0048] The polymerization method for the polyacetal copolymer is not particularly limited, but is generally performed by bulk polymerization, and either a batch type or a continuous type is possible. The polymerization apparatus used is a self-cleaning type extrusion kneader such as a co-kneader, a twin-screw type continuous extrusion kneader, or a twin-screw type continuous mixer, and a molten monomer is supplied to the polymerization apparatus, and a solid bulk polyacetal copolymer is obtained as the polymerization proceeds.

[0049] The MFR of the polyacetal resin is preferably 1 to 50 g / 10 min from the viewpoint of further suppressing the generation of formaldehyde gas. The MFR can be measured by the method described in the Examples below.

[0050] The mass ratio of the polyacetal resin to 100 mass% of the polyacetal resin composition of the present embodiment is preferably 80 mass% or more, more preferably 90 mass% or more, and even more preferably 95 mass% or more, and may be 95 mass% or less, 99 mass% or less, or less than 100 mass%.

[0051] The mass proportion of the above compound relative to 100 mass% of the polyacetal resin composition of the present embodiment is preferably more than 0 mass% and not more than 20 mass%, more preferably 0.01 to 10 mass%, and even more preferably 0.05 to 3 mass%.

[0052] The total mass proportion of the polyacetal resin and the above compounds relative to 100 mass% of the polyacetal resin composition of the present embodiment is preferably 95 mass% or more, more preferably 97 mass% or more, and even more preferably 100 mass%.

[0053] The mass ratio of the polyacetal resin relative to 100 mass% of the resin components contained in the polyacetal resin composition of the present embodiment is preferably 70 mass% or more, more preferably 90 mass% or more, and even more preferably 100 mass%.

[0054] In the polyacetal resin composition of the present embodiment, the molar ratio of the above compound to 100 g of the above polyacetal resin is preferably 0.01 to 100 mmol, more preferably 0.1 to 50 mmol, and even more preferably 0.3 to 20 mmol.

[0055] The amount of formaldehyde generated from the polyacetal resin composition of the present embodiment is preferably less than 15 mg / kg, and more preferably 10 mg / kg or less. The amount of formaldehyde generated can be measured by the method described in the Examples below.

[0056] The polyacetal resin composition of the present embodiment can be produced, for example, by a known melt kneading method. For example, the polyacetal resin and the compound may be mixed in a stirrer such as a Henschel mixer and then supplied to a single-screw or twin-screw melt kneading device (extruder) for melt kneading, or the polyacetal resin may be supplied from the upstream of a single-screw or twin-screw extruder and brought to a molten state, and then the compound may be supplied downstream and melt kneaded.

[0057] The polyacetal resin composition of the present embodiment can be used as a raw material for molded products. It can be molded into any shape, and can be used for, for example, injection molded products, fibers / nonwoven fabrics, sheets / films, profile extrusion products, etc.

[0058] [Method to suppress formaldehyde emissions from polyacetal resin] The above compound can capture formaldehyde generated from polyacetal resin. The method for suppressing formaldehyde emissions from a polyacetal resin according to the present embodiment includes mixing the above-described compound with the polyacetal resin. For example, when the polyacetal resin and the compound are mixed to form a polyacetal resin composition and then molded or the like, the compound captures formaldehyde gas generated by decomposition of the polyacetal resin during molding, thereby making it possible to reduce the amount of formaldehyde gas generated.

[0059] In the method of suppressing formaldehyde emission from a polyacetal resin of the present embodiment, the molar ratio of the compound to 100 g of the polyacetal resin is preferably 0.01 to 100 mmol, more preferably 0.1 to 50 mmol, and even more preferably 0.3 to 20 mmol.

[0060] [How to use the compound] The method of using the compound of the present embodiment is a method of using the compound to suppress formaldehyde emission from a polyacetal resin. The method of using the compound of the present embodiment may be the method of using the compound described above.

[0061] The compound in the method of using the compound of the present embodiment is the compound contained in the polyacetal resin composition of the present embodiment described above. The compound of the present embodiment is used in an amount of preferably 0.01 to 100 mmol, more preferably 0.1 to 50 mmol, and even more preferably 0.3 to 20 mmol, per 100 g of the polyacetal resin. EXAMPLES

[0062] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0063] The raw material components used in the examples and comparative examples are as follows.

[0064] (Polyacetal resin) Copolymer A polyacetal resin copolymer (MFR=9.0g / 10min) was used, which was obtained by copolymerizing trioxane and 1,3-dioxolane (4.2 mol% relative to the resin). The MFR value was measured in accordance with ISO 1133-1 using a MELT INDEXER manufactured by Toyo Seiki Seisakusho Co., Ltd., at a cylinder temperature of 190° C. and a load of 2.16 kg. Homopolymer A polyacetal resin homopolymer (MFR = 20.0 g / 10 min) obtained by polymerizing formaldehyde was used. The MFR value was measured in accordance with ISO 1133-1 using a MELT INDEXER manufactured by Toyo Seiki Seisakusho Co., Ltd., at a cylinder temperature of 190°C and a load of 2.16 kg.

[0065] (compound) B1: 3-(Dimethylamino)-2-propenal (Tokyo Chemical Industry Co., Ltd.) B2:3-Dimethylamino-1-(3-pyridyl)-2-propen-1-one (Santa Cruz Biotechnology, Inc.) B3:3-(Methylphenylamino)-2-propenal (Santa Cruz Biotechnology, Inc.) B4:Ethyl 3-(ethylamino)-2-propenoate (Alfa Chemistry) B5: 4-amino-3-penten-2-one (Tokyo Chemical Industry Co., Ltd.) B6: Methyl-3-amino-2-butenoate (Tokyo Chemical Industry Co., Ltd.) B7:3-Amino-2-butenamide (Angene Chemical) B8: 2-Butenoic acid, 3-amino-, 1-methylethylester (Tokyo Chemical Industry Co., Ltd.) B9: Ethyl 3-amino-4,4,4-trifluoro-2-butenoate (Tokyo Chemical Industry Co., Ltd.) B10: 2-butenoic acid, 3-amino-, 1,1'-(1,4-butanediyl) ester (Tokyo Chemical Industry Co., Ltd.) B11:2-butenoic acid,3-amino-,1,1'-(thiodi-2,1-ethanediyl) ester (Finetech Industry) B12:2-Butenoic acid, 3-amino-, 1-methyl-1,3-propanediyl ester (Alfa Chemistry) B13: 3-amino-2-cyclohexen-1-one (Tokyo Chemical Industry Co., Ltd.) B14: 3-amino-5-methyl-2-cyclohexen-1-one (Tokyo Chemical Industry Co., Ltd.) B15: 3-amino-5,5-dimethyl-2-cyclohexen-1-one (Tokyo Chemical Industry Co., Ltd.) B16:5-Amino-2H-pyran-3(6H)-one (Combi-Blocks) B17:3-Amino-2-cyclopenten-1-one (Ambeed) B18:2,3-Dihydro-4(1H)-pyridinone (Combi-Blocks) B19: 6-Methyluracil (Tokyo Chemical Industry Co., Ltd.) B20: Adipic acid dihydrazide (Tokyo Chemical Industry Co., Ltd.) B21: Hydantoin (Tokyo Chemical Industry) B22: Bexoguanamine (Tokyo Chemical Industry Co., Ltd.)

[0066] The measurement and evaluation methods are as follows.

[0067] (1) Amount of formaldehyde emitted Using an injection molding machine (Toshiba Machine IS-100GN), test pieces (100 mm x 40 mm x 3 mm flat plates) were molded from the polyacetal resin compositions obtained in the Examples and Comparative Examples under the following conditions: mold temperature 80°C, cylinder temperature 220°C, injection pressure 35 MPa, injection time 15 seconds, and cooling time 20 seconds. The amount of formaldehyde emitted from the test piece was measured according to the method described in the German Automotive Industry Association standard VDA275. Specifically, the test piece was hung in a 1L polyethylene bottle containing 50mL of distilled water and sealed so as not to touch the distilled water. This was heated at 60°C for 3 hours and left to stand at room temperature for 60 minutes. The formaldehyde in the distilled water was reacted with acetylacetone in the presence of ammonium ions, and the absorption peak at a wavelength of 412 nm was measured using a UV spectrometer for the reaction product to determine the amount of formaldehyde generated. The amount of formaldehyde generated was expressed as the amount of formaldehyde (μg / g) per 1g of polyacetal resin. The smaller this value, the more suppressed the amount of formaldehyde generated, which is preferable.

[0068] (2) Bleed-out properties Using an injection molding machine (Toshiba Machine IS-100GN), test pieces (100 mm x 40 mm x 3 mm flat plates) were molded from the polyacetal resin compositions obtained in the Examples and Comparative Examples under the following conditions: mold temperature 80°C, cylinder temperature 220°C, injection pressure 35 MPa, injection time 15 seconds, and cooling time 20 seconds. Using a thermo-hygrostat (PL-2KT manufactured by Espec), the molded products were treated for 24 hours at 60°C and 95% RH or for 168 hours at 85°C and 95% RH. The surfaces of the molded products were then visually observed and the amount of bleeding was evaluated according to the following criteria. 〇(Excellent): No bleeding out observed △(Good): The surface becomes slightly cloudy overall. × (Poor): Dark bleeding is observed throughout, and the color appears powdery.

[0069] [Examples 1 to 33, Comparative Examples 1 to 5] The compositions shown in Tables 1 and 2 were mixed and fed to a twin-screw extruder (PCM30 manufactured by Ikegai), melt-kneaded at a screw rotation speed of 60 rpm and a cylinder temperature setting of 200°C, and then pelletized. The pellets obtained were dried for 3 hours using a hot air dryer at a temperature of 80°C, and then molded and evaluated by the above method. The evaluation results are summarized in Tables 1 and 2.

[0070]

Table 1

[0071]

Table 2

Claims

1. A polyacetal resin composition comprising a compound having at least one structure represented by the following formula (1) and a polyacetal resin: 【Chemistry 1】 (In formula (1), *1 to *4 represent bonds.)

2. The polyacetal resin composition according to claim 1, comprising 0.01 to 100 mmol of the compound per 100 g of the polyacetal resin.

3. The compound is A part or all of the structure contained in the compound is Any two of *1 to *4 in the structure are bonded directly or via a linking portion to form a ring structure. The polyacetal resin composition according to claim 1 or 2.

4. The compound is A part or all of the structure contained in the compound is In the structure, *3 and *4 are bonded directly or via a linking moiety to form a ring structure, and the linking moiety is an optionally substituted alkylene group or heteroalkylene group. The polyacetal resin composition according to claim 1 or 2.

5. The compound is A part or all of the structure contained in the compound is The *3 and the *4 in the structure are bonded directly or via a linking moiety to form a ring structure, the linking moiety is an optionally substituted alkylene group or heteroalkylene group, and at least one of the *1 and the *2 in the structure is a hydrogen atom. The polyacetal resin composition according to claim 1 or 2.

6. The compound is having one of the above structures, The *1 and *2 are each independently a hydrogen atom, an alkyl group, a halogenated alkyl group, an aryl group, or an ester group, The *3 is a hydrogen atom, an alkyl group, a halogenated alkyl group, a thioalkyl group, an ether group, or an alkoxy group, The *4 is a hydrogen atom, an alkyl group, a thioalkyl group, an aryl group, a heteroaryl group, an amino group, an aminoalkyl group, an ether group, or an alkoxy group. The polyacetal resin composition according to claim 1 or 2.

7. The polyacetal resin composition according to claim 6, wherein at least one of *1 and *2 in the structure is a hydrogen atom.

8. The compound is The polyacetal resin composition according to claim 1 or 2, which has two or more of the structures, and any of *1 to *4 in the different structures are bonded directly or via a linking portion.

9. The compound is A compound having two or more of the above structures, wherein the *4 in different structures are bonded to each other via a linking moiety, and the linking moiety is a structure consisting of at least one selected from the group consisting of an optionally substituted ether group, a thioether group, an ester group, and an alkylene group. The polyacetal resin composition according to claim 1 or 2.

10. The compound is has two or more of the above structures, the *4 in different structures are bonded to each other via a linking moiety, and the linking moiety is a structure consisting of at least one selected from the group consisting of an optionally substituted ether group, a thioether group, an ester group, and an alkylene group, The above *1 and *2 are each independently a functional group selected from the group consisting of a hydrogen atom, an alkyl group, a halogenated alkyl group, an aryl group, and an ester group, The *3 is a hydrogen atom, an optionally substituted alkyl group, a halogenated alkyl group, a thioalkyl group, or an alkoxy group. The polyacetal resin composition according to claim 1 or 2.

11. 3. The polyacetal resin composition according to claim 1 or 2, except for the case where the compound is a compound in which all of the structures contained in the compound are compounds in which a nitrogen atom and a carbon atom at the alpha position of a carbonyl group in formula (1) form a 6-membered aromatic ring.

12. The polyacetal resin composition according to claim 1 or 2, except where the compound is uracil.

13. A method for suppressing formaldehyde emission from a polyacetal resin, comprising mixing a compound having at least one structure represented by the following formula (1) with the polyacetal resin. 【Chemistry 2】 (In formula (1), *1 to *4 represent bonds.)

14. A use of a compound having at least one structure represented by the following formula (1) for suppressing formaldehyde emission from a polyacetal resin. 【Chemistry 3】 (In formula (1), *1 to *4 represent bonds.)

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