CN103073837A - Polyacetal resin - Google Patents

Abstract

The present invention efficiently provides a polyacetal resin composition which can effectively restrain black point foreign matter and has the advantages of high reliability, high hot water resistance and excellent practical rigidity. The retention rate of the polyacetal resin based on ISO527 tensile breaking strength after 10-day hot water experiment at a temperature of 130 DEG C is above 70%, and furthermore standard deviation sigma of the tensible breaking strength value of each experiment is within a range of 0<=sigma<=10.

Description

Polyacetal resin

Technical field

The present invention relates to polyacetal resin.

Background technology

Polyacetal resin has following advantage: processibility, productivity are good, can be shaped, melt extrude by melt injection product or parts that the manufacturing process such as shaping come efficiently production intended shape.By bringing into play above-mentioned advantage, the material that polyacetal resin is used as electric and electronic Material Field, automotive field, other various Industrial materials fields, food product pack field and parts and being used widely.For such use, high to the aging resistance of heat, wherein aging resistance performance when wall thickness is thicker of hot water is reduced sooner, and deviation also increases, and therefore expects the polyacetal resin that reliability is high.

As the characteristic of above-mentioned requirements, have the original high-performance that has of polyacetal resin, for example in the above-mentioned good mechanical characteristics balance, on the other hand, sometimes requiring to improve thermostability, aging property under harsh environment for use.In recent years, along with the densification of electric, electronics, be used for improving the battery use of environment and hot-water supply system's development, situation about using in the temperature range more than 100 ℃ increases, thereby has the balance height of thermostability and mechanical characteristics and the high characteristic of reliability and become and become more and more important.

In order to address the above problem, various schemes have been proposed up to now, for example, proposed to add by organic acid or alcohol with 2 ~ 30 carbon atoms method with the metal-salt/polymeric amide (patent documentation 2) of the method (patent documentation 1) that is selected from metal-salt that the metal in the group that is comprised of basic metal, alkaline-earth metal consists of and hydrotalcite or interpolation hindered phenol/carboxylic acid.In addition, proposed by strengthening with glass fibre can the withstand hot water test polyacetal resin (patent documentation 3).

On the other hand, the cry that requires to produce efficiently the few high purity polyacetal resin of metal content also grows to even greater heights.In the applied field of polyacetal resin, also just at miniaturization, the precise treatment of propulsion component, and advancing the thin-walled property of molding, minute sized metallic foreign body not noticeable thereby that do not become problem began to become problem in the past, in addition, sometimes make mould produce damage etc. with the die surface power friction during owing to be shaped, thereby expect to contain the still less polyacetal resin of metallic foreign body.

For example, in the industrial manufacturing process of in the past polyacetal resin, because the etch of pipe arrangement burn into pipe arrangement, the metal wearing and tearing due to being in contact with one another etc. may be sneaked into the metal take the Fe element as main component that derives from the shop equipment works.In the situation of sneaking into the metal that derives from the works that consists of above-mentioned shop equipment etc., because its amount and the opportunity of sneaking into are unfixing, therefore, high-quality in order stably to guarantee, the content of also thirsting for making magnetic substance metal is that the following metal of 1ppm is sneaked into few high purity polyacetal resin.Particularly in the purposes such as thin molded article or diaphragm, there is demand in the polyacetal resin of not sneaking into the metal more than the 150 μ m.

Therefore the proportion of metal, when the product bag internal classification, produce the part that has a large amount of tramp m.s up to more than 4 times of polyacetal resin with point-like.

Therefore think, according to using polyacetal resin as the raw material timing input in the melt-processed operation of raw material, also can produce the black foreign matter with point-like.In addition, the problem that also exists the static accumulated because of the mutual friction of polyacetal resin phase to make contained metal be difficult to remove.

As the method that is generally used for removing foreign matter, following method is arranged: when utilizing forcing machine etc. to carry out melting mixing, on the path that molten resin flows through from the metal-made net by filtering out foreign matter.The aperture of net is set to such an extent that more littlely more can remove foreign matter, difficulty flows and production efficiency is reduced but resin becomes extremely, in addition, can make the metal that flows simultaneously with raw material mixing in resin and the difficulty that becomes is extremely removed, in addition, the high metal of long-width ratio passes through from net etc. sometimes, and therefore, expectation obtains method polyacetal resin, high productivity that metal is fully removed.About making in the polyacetal resin the not technology of tramp m. foreign matter, proposed to make the content of lithium as the metal in the polyacetal resin, sodium, potassium, iron, copper, chromium, nickel to be respectively method (for example referring to Patent Document 4) below the 5 quality ppm.

In addition, as the method that the foreign matter in the polymkeric substance is removed, proposed following technology: metallic foreign body stops up hot runner when utilizing hot runner to carry out injection forming in order to be suppressed at, and utilizes magnetic grader to carrying out sorting (only take out metal and sneak into few particle) (for example referring to Patent Document 5) for the particle in injection forming.

The prior art document

Patent documentation

Patent documentation 1: Japanese JP 8-3025 communique

Patent documentation 2: Japanese kokai publication hei 3-14859 communique

Patent documentation 3: Japanese kokai publication hei 11-181231 communique

Patent documentation 4: Japanese kokai publication hei 7-188514 communique

Patent documentation 5: TOHKEMY 2004-99682 communique

Summary of the invention

Invent problem to be solved

But, do not mention the hot water performance under the high temperature in the patent documentation 1, do not mention reliability yet, thereby can not fully hold the height of reliability.In the method for patent documentation 2 record because the stabilization of polyacetal resin is insufficient, therefore, shaping add the thermostability in man-hour and generation mold deposit aspect can not be satisfactory.

In addition, the polyacetal resin of patent documentation 3 can fully be implemented hot water test, but then, must need the fibrous inorganic fillers such as glass fibre, and potentiality ground has the danger of fibre shedding, the atmosphere around may polluting during life-time service.

The metal that disclosed method stays in for reducing in the polyacetal resin in the patent documentation 4 passes through to use glass container made (not using the method for metal-made equipment fully) to reduce the method for metal, manufacturing in the time of can only realizing minute quantity from the viewpoint of industrial application is inadequate as efficient production method.

In addition; the technology that the technology of patent documentation 5 specifically makes resin particle pass through in magnetic grader; can not remove fully the metal that is included in granule interior; in addition; thereby the bump of the particle that can be passed through because of own wt and back by the particle of the temporary transient absorption of magnet drops and is difficult to thoroughly remove; for the foregoing reasons, removing of metallic foreign body is inadequate.

The inventor conducts in-depth research for the problem of above-mentioned prior art, found that, the magnetic substance metal is the reason that produces variety of issue when the melt-processed of polyacetal resin.

The present invention finishes in view of the problem of above-mentioned prior art, its purpose be to provide with high reliability have high hot water resistance, be attached to (mold deposit) on the mould in the time of can preventing injection forming, variable color due to aging is few, have practical good rigidity and have the polyacetal resin composite of high aging property.In addition, the object of the present invention is to provide the manufacture method that produces the black foreign matter in the time of effectively to suppress melt-processed, can make efficiently the polyacetal resin of high purity polyacetal resin.

For the means of dealing with problems

The inventor conducts in-depth research in order to address the above problem, and found that, by numerically determining the amount of the magnetic substance metal in the polyacetal resin, can address the above problem, thereby finish the present invention.

That is, the present invention is as described below.

[1] a kind of polyacetal resin, its after carrying out hot water test in 10 days under 130 ℃, be more than 70% based on the conservation rate of the fail in tension intensity of ISO527, and the standard deviation sigma of the fail in tension intensity level of test is the scope of 0≤σ≤10 each time.

[2] such as above-mentioned [1] described polyacetal resin, wherein, the content of magnetic substance metal is below the 1ppm.

[3] such as above-mentioned [1] described polyacetal resin, wherein, the conservation rate of above-mentioned fail in tension intensity is more than 70%, and standard deviation sigma is the scope of 0≤σ≤5.

[4] such as above-mentioned [1] described polyacetal resin, wherein, above-mentioned polyacetal resin contains at least a above fatty acid metal salt.

[5] such as above-mentioned [1] described polyacetal resin, wherein, the conservation rate of above-mentioned fail in tension intensity is more than 90%, and standard deviation sigma is the scope of 0≤σ≤5.

[6] such as above-mentioned [1] described polyacetal resin, wherein, above-mentioned polyacetal resin is the polyacetal resin multipolymer.

[7] a kind of manufacture method of polyacetal resin comprises:

Obtain the operation of polyacetal resin by polymerization, and

The powder that makes above-mentioned polyacetal resin in possessing magnetic force and produce the magnet separator in source by and thereby the magnetic substance metal in the polyacetal resin is removed the content that obtains this magnetic substance metal is the operation of the polyacetal resin below the 1ppm.

[8] such as the manufacture method of above-mentioned [7] described polyacetal resin, wherein, the volume average particle size of the powder of above-mentioned polyacetal resin is below the 3mm.

[9] such as the manufacture method of above-mentioned [7] described polyacetal resin, wherein, the powder that makes above-mentioned polyacetal resin above-mentioned possess in the magnet separator that magnetic force produces the source by the time, the magnetic force in the zone that the magnetic substance metal is removed from the powder of above-mentioned polyacetal resin is more than 0.6 tesla.

[10] such as the manufacture method of above-mentioned [7] described polyacetal resin, wherein, the magnetic force that uses in the above-mentioned magnet separator produces the source and is electro-magnet.

[11] such as the manufacture method of above-mentioned [7] described polyacetal resin, wherein, the powder of above-mentioned polyacetal resin is passed through between the above-mentioned magnetic force generation source with the arranged spaced below the 15mm.

[12] such as the manufacture method of above-mentioned [7] described polyacetal resin, wherein, the magnetic force effective separation length of above-mentioned magnet separator is more than the 100mm.

[13] such as the manufacture method of above-mentioned [7] described polyacetal resin, wherein, the content by the magnetic substance metal in the polyacetal resin after the magnet separator is below the 0.1ppm.

[14] such as the manufacture method of above-mentioned [7] described polyacetal resin, wherein, in the polyacetal resin after the magnet separator, maximum width be the above magnetic substance metal of 150 μ m be 0.1/below the kg.

[15] a kind of polyacetal resin, it obtains by each described method in above-mentioned [7] ~ [14], and the content of magnetic substance metal is below the 1ppm.

The invention effect

According to the present invention, can provide efficiently the polyacetal resin that can effectively suppress the stain foreign matter, have high hot water resistance and have practical good rigidity with high reliability.

The small shaping product material that uses in various component materials, diaphragm material, machinery or the device of polyacetal resin of the present invention as electric and electronic Material Field, automotive field, other various Industrial materials fields etc., the wrapping material of food have the utilizability on the industry.

Embodiment

Below, at length describe being used for implementing mode of the present invention (hereinafter referred to as " present embodiment ").

Need to prove that the present invention is not subjected to the restriction of following embodiment, can in its purport scope, carry out various distortion and implement.

Polyacetal resin of the present invention refer to that the homopolymerization by cyclic oligomers such as formaldehyde or trioxane or four amylene oxide obtains in fact by oxidation MU (methylene unit)-(CH ₂O)-the polyoxymethylene homopolymer that consists of and have by formaldehyde or trioxane and cyclic ether or cyclic formals or be added with that the copolymerization of cyclic formals of the hindered phenol anti-oxidants of 1 ~ 500ppm obtains by oxidation MU (methylene unit)-(CH ₂O)-randomly be inserted with the teracol base co-polymer by the structure of the alkylidene oxide unit of following general formula (1) expression in the chain that consists of.

(the R in the formula ₁And R ₂Be respectively hydrogen atom, alkyl or aryl, they can be the same or different, and n is 2 ~ 6 integer)

In addition, the polyoxymethylene that uses among the present invention also comprise molecular chain branch side chain teracol base co-polymer and with the teracol group block copolymer of the xenogenesis composition block of the repeating unit that contains the oxidation methylene radical more than 50 % by weight.

Need to prove that the insertion rate of the above-mentioned alkylidene oxide unit in the teracol base co-polymer is 0.01 ~ 50 mole with respect to 100 moles of oxidation MU (methylene unit), is preferably 0.03 ~ 20 mole scope.As this alkylidene oxide unit, can enumerate such as oxidation ethylidene unit, oxypropylene unit, oxidation tetramethylene unit, oxybutylene unit, oxidation phenyl ethylidene unit etc.In the above-mentioned alkylidene oxide unit, from the viewpoint of the physical property that improves polyacetal resin composite, particularly preferably oxidation ethylidene unit-[(CH ₂) ₂O]-and oxidation tetramethylene unit-[(CH ₂) ₄O]-.

Preferably the above-mentioned polyoxymethylene that obtains by homopolymerization or copolymerization is carried out the stabilization treatment of molecular end.As the stabilization treatment method of molecular end, can use such as: make the method for terminal hydroxy esterification, etherificate, ammonia esterification etc. or realize the method etc. of the stabilization of molecular end by the l fraction hydrolysis with molecular end.

Above-mentioned polyoxymethylene can obtain by for example following method: will be by formaldehyde or trioxane and cyclic ether, the teracol base co-polymer that the copolymerization of cyclic formals obtains carries out the stabilization treatment of molecular end immediately after polymerization, then further under molten state, supply at least continuously and comprise: 1. injected water or alcohol or their mixture and carry out mixing operation and 2. and discharge the non-occlusal pattern twin screw extruder of counter rotating of operation in these two stages of devolatilization operation of the steam of above-mentioned hydroxy-containing compounds of injection and free formaldehyde and process, from the teracol base co-polymer of melting, remove volatile component thus, etc.Need to prove, inject above-mentioned water or alcohol or their mixture and carry out when mixing, preferably add the alkaline matter such as triethylamine as pH adjusting agent.

The method for making of＜polyoxymethylene homopolymer 〉

Homopolymerization by cyclic oligomers such as formaldehyde or trioxane or four amylene oxide obtain in fact by oxidation MU (methylene unit)-(CH ₂O)-two ends of the teracol basis representation polymer chain that consists of are by the polyoxymethylene homopolymer of ester group or ether sealing, can with formaldehyde and known molecular weight regulator as raw material, use known

The salt polymerizing catalyst, utilizes the polymerization process that known slurry process for example puts down in writing in Japanese Patent Publication 47-6420 communique, the Japanese Patent Publication 47-10059 communique and obtains as solvent with hydrocarbon etc.At this, the impurity such as preferred formaldehyde is not moisture, methyl alcohol.

As polymerizing catalyst, so long as the anionic species polymerizing catalyst then is not particularly limited, for example be conduct

The catalyzer by following general formula (2) expression of salt polymerizing catalyst.

[R ₃R ₄R ₅R ₆M] ⁺X ^- …(2)

(in the formula, R ₃, R ₄, R ₅, R ₆Represent independently of one another alkyl, M represents to have the element of lone-pair electron, and X represents nucleophilic group)

Represented by above-mentioned general formula (2)

In the salt polymerizing catalyst, preferably use the tetraethyl-iodate

The iodate of tributyl ethyl

In season

The quaternary ammonium compounds such as salt compounds or 4 bromide, dimethyl distearyl ammonium acetate.More preferably use dimethyl distearyl ammonium acetate.

The import volume of polymerizing catalyst is 0.0001 ~ 0.01 mole with respect to the 1kg monomer preferably, more preferably 0.0005 ~ 0.005 mole, is particularly preferably 0.001 ~ 0.003 mole.When import volume was less than 0.0003 mole, polymerization velocity was slack-off, and yield reduces, from not preferred economically.Import volume is during more than 0.01 mole, and it is inhomogeneous that polymerization system becomes easily, thereby not preferred.As molecular weight regulator, can use alcohol, carboxylic acid anhydride or carboxylic acid, be preferably methyl alcohol, ethanol, propionic anhydride, diacetyl oxide, be particularly preferably diacetyl oxide.The import volume of molecular weight regulator is 0.005 ~ 0.008 mole scope with respect to the 1kg monomer.

As the hydrocarbon equal solvent, so long as then can not be any hydrocarbon with the compound of formaldehyde reaction, preferred pentane, iso-pentane, hexane, hexanaphthene, heptane, octane, nonane, decane, benzene etc.Be particularly preferably hexane.In addition, also can be use mixing two or more.

Poly-unit so long as can supply with simultaneously formaldehyde, molecular weight regulator,

The device of salt polymerizing catalyst then is not particularly limited, and can use known device, can be intermittent type, continous way etc.Be preferably the continous way poly-unit.

The end group of the polyacetal resin homopolymer that obtains like this mostly is greatly hydroxyl, thereby to thermally labile, therefore, need to make terminal stabilization.

As the method that makes terminal stabilization, can enumerate the method that the chemical treatment conditions with the end group under the known temperature obtains.That is, with respect to the chemical processing agent of 1kg polymkeric substance input 0.1 ~ 90kg, process under 140 ~ 150 ℃ temperature, the time is 20 ~ 100 minutes.Device can be that continous way can be intermittent type also, is preferably the continous way device.In addition, chemical processing agent can use the chemical processing agent such as esterifying agent, etherifying agent, and the end group chemical processing agent among preferred the present invention uses the method for esterifying agent.

Use esterifying agent to have as the method for chemical processing agent: the method that the gas of the use acid anhydrides of putting down in writing in No. 3172736 specification sheets of method, United States Patent (USP) that a large amount of acid anhydrides of use of putting down in writing in No. 3459709 specification sheets of United States Patent (USP) are processed under slurry state is processed under gas phase.

As the esterifying agent that uses in the end group chemical treatment, for the method for under slurry state, processing, use gas for any one method in the method for processing under the gas phase, all can enumerate by the organic acid anhydride of following general formula (3) expression or benzoyl oxide, succinyl oxide, maleic anhydride, Pyroglutaric acid, Tetra hydro Phthalic anhydride etc.

R ₇COOCOR ₈ …(3)

(in the formula, R ₇, R ₈Represent independently of one another alkyl.R ₇, R ₈Can be the same or different)

In the organic acid anhydride by above-mentioned general formula (3) expression, preferred propionic anhydride, diacetyl oxide, particularly preferably diacetyl oxide.Organic acid anhydride can use a kind of, also can use two or more.

As the method for using etherifying agent as chemical processing agent, Japanese Patent Publication 63-452 communique etc. is arranged, as the etherifying agent that uses in the terminal stabilization of the present invention, can from ortho ester, select, described ortho ester is generally the ortho ester that aliphatic acid or aromatic acid and fatty alcohol, ester ring type alcohol or aromatic alcohols form, for example original acid A ester or ethyl orthoformate, ortho-acetic acid methyl esters or ethyl orthoacetate, former methyl benzoate or former ethyl benzoate and orthocarbonic ester ethyl orthocarbonate for example.

In etherification reaction, can import with respect to the 1kg etherifying agent is the lewis acid catalysts such as middle intensity mineral acid such as the middle intensity organic acid such as tosic acid, acetic acid and Hydrogen bromide, methyl-sulfate and ethyl sulfate of 0.001 ~ 0.02kg.

The preferred solvent of etherification reaction is: lower boiling aliphatic hydrocarbon, ester ring type hydrocarbon and the aromatic hydrocarbonss such as pentane, hexane, hexanaphthene and benzene; The organic solvents such as halo lower aliphatic such as methylene dichloride, chloroform and tetracol phenixin.

The mode of polymerization is not particularly limited, and in order to obtain easily the powder of polyoxymethylene homopolymer, is preferably slurry polymerization, mass polymerization.

The method for making of＜teracol base co-polymer 〉

By formaldehyde or trioxane and cyclic ether or cyclic formals or be added with that the copolymerization of cyclic formals of the hindered phenol anti-oxidants of 1 ~ 500ppm obtains, have by oxidation MU (methylene unit)-(CH ₂O)-multipolymer of structure that randomly is inserted with the alkylidene oxide unit of following general formula (1) expression in the chain that forms is the teracol base co-polymer.

(the R in the formula ₁And R ₂Be respectively hydrogen atom, alkyl or aryl, they can be the same or different, and n is 2 ~ 6 integer)

Trioxane is the cyclic trimer of formaldehyde, generally obtains by in the presence of an acidic catalyst formalin being reacted.Contain water, methyl alcohol, formic acid, methyl-formiate etc. in this trioxane and make chain that the impurity that shifts occur, therefore, preferably remove above-mentioned impurity by methods such as distillations and carry out purifying.In this situation, the total amount that preferably makes chain that the impurity of transfer occurs is 1 * 10 with respect to 1 mole of trioxane ^-3Below the mole.More preferably 0.5 * 10 ^-3Below the mole.The total amount that makes the impurity that chain occur to shift is measured when above for this, the polymerization rate that can slow down, and can make the thermostability variation of the polymkeric substance of generation.

Cyclic ether and/or cyclic formals be can with the composition of trioxane copolymerization, particularly, can enumerate: oxyethane, propylene oxide, butylene oxide ring, Epicholorohydrin, epibromohydrin, phenyl ethylene oxide, trimethylene oxide (オ キ サ タ ソ), 1,3-dioxolane, ethylene glycol acetal, propylene glycol formal, Diethylene Glycol formal, triethylene glycol formal, 1,4-butyleneglycol formal, 1,5-pentanediol formal, 1,6-hexylene glycol formal etc.In above-mentioned cyclic ether and/or the cyclic formals, preferred 1,3-dioxolane, BDO formal.

The addition of cyclic ether and/or cyclic formals is 1 ~ 20 % by mole scope with respect to 1 mole of trioxane.Be preferably 1 ~ 15 % by mole, more preferably 1 ~ 10 % by mole, most preferably be 1 ~ 5 % by mole.

As polymerizing catalyst, preferred Lewis acids, protonic acid and the cation activity catalyzer such as ester or acid anhydrides thereof.As Lewis acid, for example can enumerate: the halogenide of boric acid, tin, titanium, phosphorus, arsenic and antimony, particularly, can enumerate: boron trifluoride, tin tetrachloride, titanium tetrachloride, phosphorus pentafluoride, phosphorus pentachloride, antimony pentafluoride and complex compound thereof or salt.In addition, as the ester of protonic acid, protonic acid or the concrete example of acid anhydrides, can enumerate: perchloric acid, trifluoromethanesulfonic acid, heteropolyacid, isopoly-acid, the perchloric acid tert-butyl ester, acetyl perchloric acid (ァ セ チ Le パ one Network ロ ラ one ト), trimethylammonium oxygen

Hexafluorophosphate etc.Wherein, preferred boron trifluoride, boron trifluoride hydrate and contain Sauerstoffatom or the co-ordination complex of the organic compound of sulphur atom and boron trifluoride formation particularly, can be enumerated boron trifluoride diethyl ether, boron trifluoride di-n-butyl ether as preference.The usage quantity of above-mentioned polymerizing catalyst is preferably 1 * 10 with respect to 1 mole of the total amount of trioxane and cyclic ether and/or cyclic formals ^-6Mole ~ 1 * 10 ^-3Mole, more preferably 5 * 10 ^-6Mole ~ 1 * 10 ^-4Mole.

Add in the monomer after using the inert solvent that polyreaction is had no adverse effect to dilute the above-mentioned catalyzer that uses among the present invention, this is being preferred aspect making that reaction evenly carries out.Solvent as being used for dilute catalyst then all can not use so long as do not participate in the Organic solvent of polyreaction.Can use such as the aromatic hydrocarbon such as benzene,toluene,xylene, the aliphatic hydrocarbons such as normal hexane, normal heptane, hexanaphthene, the halohydrocarbon such as chloroform, methylene dichloride, the ethers such as ether, diethylene glycol dimethyl ether, Isosorbide-5-Nitrae-dioxane.Above-mentioned solvent need to make moisture as mentioned above in specific scope, and uses after need to utilizing zeolite etc. fully to remove moisture.

As the polymerization process of polyacetal resin multipolymer, can adopt any one method in slurry process, substance law, the scorification.In addition, the shape of the polymerization reactor of use (structure) also is not particularly limited, and preferably uses in the chuck oar formula or the screw of twin shaft that can be by thermal medium to mix the type poly-unit.As the poly-unit that is used for carrying out the continuous bulk polymerization reaction, can use the self-clean types such as kneader, the continuous extruder and mixing roll of double-screw type, twin shaft oar formula continuous mixer to extrude mixing machine, can use in addition the continuous polymerization unit of the trioxane that proposed at present etc.The temperature of polymerization reactor preferably remains on 63 ~ 135 ℃, and more preferably 70 ~ 120 ℃ scope most preferably is 70 ~ 100 ℃ scope.Delay (reaction) time in the polymerization reactor is preferably 0.1 ~ 30 minute, more preferably 0.1 ~ 25 minute, most preferably is 0.1 ~ 20 minute.There are the tendency that continues to carry out stable polyreaction the temperature of polymerization reactor and residence time when being above-mentioned scope.

The inactivation of the polymerizing catalyst that contains in the rough methylene oxide polymer that obtains by the continuous bulk polymerization reaction of using the cation activity catalyzer carries out by the following method: rough methylene oxide polymer is put in the catalyzer such as oxyhydroxide, inorganic acid salt, organic acid salt of amines such as containing ammonia, triethylamine, tri-n-butylamine, boronic acid compounds class or basic metal or alkaline-earth metal and in the aqueous solution and/or organic solvent of deactivator, under slurry state usually stirred for several minute to a few hours.At this moment, be in the situation of relatively large shape at rough polyacetal resin multipolymer, preferably after polymerization, pulverize first and process again.Then, undertaken by filtration drying.

As in the catalyzer and deactivator, can use separately quaternary ammonium compound, can with quaternary ammonium compound and above-mentioned catalyst deactivation agent and usefulness, be preferred method for more effectively carrying out the catalyzer neutralization also perhaps.In addition, following method is useful: contact the method that makes catalyst deactivation with rough methylene oxide polymer by the steam that makes ammonia, triethylamine etc., contact the method that makes catalyst deactivation by making at least a and rough methylene oxide polymer in hindered amines, triphenylphosphine, calcium hydroxide, boronic acid compounds or the quaternary ammonium compound etc. in mixing machine.

Rough methylene oxide polymer behind the polymerizing catalyst inactivation exists heat-labile terminal portions, therefore, unsettled terminal portions is implemented to decompose remove and make its stabilization.

As unstable terminal portions is decomposed the method for removing, can enumerate the method that for example comprises at least the operation in following two stages: in the presence of alkaline matter, polymkeric substance carried out the operation of melting mixing and will decompose the operation that the formaldehyde opening of generation is removed.As device, preferred use can implement continuously above-mentioned two stages operation with the single-screw forcing machine of ventilation hole or with the twin screw extruder of ventilation hole etc.As above-mentioned alkaline matter, can enumerate: the oxyhydroxide/inorganic acid salt of the basic metal such as the amines such as ammonia, triethylamine, tri-n-butylamine, calcium hydroxide or alkaline-earth metal/organic acid salt, quaternary ammonium compound etc.When particularly using the quaternary ammonium compound of following formula (4) expression, can within the extremely short time, obtain the hardly oxidation methylene radical multipolymer of residual unstable terminal portions with the addition of minute quantity, therefore most preferably.In addition, above-mentioned alkaline matter can use with water or methyl alcohol, also can and use two or more alkaline matters.

[R ₉R ₁₀R ₁₁R ₁₂N ⁺] _mX ^-m …(4)

(in the formula, R ₉, R ₁₀, R ₁₁, R ₁₂The alkaryl that the aryl that represents independently of one another aralkyl that the not substituted alkyl of aryl, carbonatoms 1 ~ 30 of the not substituted alkyl of carbonatoms 1 ~ 30 or substituted alkyl, carbonatoms 6 ~ 20 or substituted alkyl are replaced by the aryl of at least one carbonatoms 6 ~ 20 or carbonatoms 6 ~ 20 is replaced by the not substituted alkyl of at least one carbonatoms 1 ~ 30 or substituted alkyl, substituted alkyl or substituted alkyl are not straight chain shape, chain or ring-type.The substituting group of above-mentioned substituted alkyl is halogen, hydroxyl, aldehyde radical, carboxyl, amino or amide group.In addition, the hydrogen atom of above-mentioned not substituted alkyl, aryl, aralkyl, alkaryl can be replaced by halogen.M represents 1 ~ 3 integer.X represents the carboxylic acid of hydroxyl or carbonatoms 1 ~ 20, the sour residue of the organic thioic acid sulfoacid that contains hydracid, oxygen acid, inorganic thioic acid sulfoacid or carbonatoms 1 ~ 20 beyond the haloid acid)

Quaternary ammonium compound is so long as the compound that is represented by above-mentioned formula (4) then is not particularly limited the R in the preferred above-mentioned formula (4) ₉, R ₁₀, R ₁₁And R ₁₂Be the alkyl of carbonatoms 1 ~ 5 or the hydroxyalkyl of carbonatoms 2 ~ 4 independently of one another, wherein, further R particularly preferably ₉, R ₁₀, R ₁₁And R ₁₂In at least one be the compound of hydroxyethyl.Particularly, can enumerate: tetramethyl-ammonium, tetraethyl ammonium, tetrapropyl ammonium, the tetra-n-butyl ammonium, cetyltrimethyl ammonium, the tetradecyl trimethyl ammonium, 1,6-hexa-methylene two (trimethyl ammonium), decamethylene two (trimethyl ammonium), trimethylammonium-3-chloro-2-hydroxypropyl ammonium, trimethylammonium (2-hydroxyethyl) ammonium, triethyl (2-hydroxyethyl) ammonium, tripropyl (2-hydroxyethyl) ammonium, three normal-butyls (2-hydroxyethyl) ammonium, tri methyl benzyl ammonium, the triethyl hexadecyldimethyl benzyl ammonium, the tripropyl hexadecyldimethyl benzyl ammonium, three normal-butyl hexadecyldimethyl benzyl ammoniums, the trimethylphenyl ammonium, triethyl phenyl ammonium, trimethylammonium-2-oxygen ethyl ammonium, monomethyl trihydroxyethyl ammonium, single ethyl trihydroxyethyl ammonium, octadecyl three (2-hydroxyethyl) ammonium, the oxyhydroxide such as four (hydroxyethyl) ammonium; Hydrochloric acid, Hydrogen bromide, hydrofluoric acid etc. contain hydrohalogenic acid salt; The oxysalts such as sulfuric acid, nitric acid, phosphoric acid, carbonic acid, boric acid, chloric acid, acid iodide, silicic acid, perchloric acid, chlorous acid, hypochlorous acid, chlorsulfonic acid, thionamic acid, two sulfuric acid, tripolyphosphate; The thiosalts such as thiosulfuric acid; Carboxylate salts such as formic acid, acetic acid, propionic acid, butyric acid, isopropylformic acid, valeric acid, caproic acid, sad, capric acid, phenylformic acid, oxalic acid etc.Wherein, preferred oxyhydroxide (OH ^-), sulfuric acid (HSO ₄ ^-, SO ₄ ^2-), carbonic acid (HCO ₃ ^-, CO ₃ ^2-), boric acid (B (OH) ₄ ^-), the salt of carboxylic acid.In the carboxylic acid, particularly preferably formic acid, acetic acid, propionic acid.Above-mentioned quaternary ammonium compound can use separately, perhaps also can be used in combination of two or more.In addition, also can and use the amines such as ammonia, triethylamine etc. on the basis of above-mentioned quaternary ammonium compound.

The addition of quaternary ammonium compound is preferably 0.05 ~ 50 ppm by weight with respect to the nitrogen amount that derives from quaternary ammonium compound that the teracol base co-polymer is converted into following mathematical expression (5) expression.

P×14/Q …(5)

(in the formula, P represents quaternary ammonium compound with respect to the concentration (ppm by weight) of teracol base co-polymer, and 14 is the nucleidic mass of nitrogen, and Q represents the molecular weight of quaternary ammonium compound)

When the addition of quaternary ammonium compound was less than 0.05 ppm by weight, Speed Reduction was removed in the decomposition of unstable terminal part, when surpassing 50 ppm by weight, and the tone variation of the teracol base co-polymer after unstable terminal portions solution removed.The addition means of quaternary ammonium compound is not particularly limited, have: the method for adding after the method in the method for in the operation that makes the polymerizing catalyst inactivation, adding with aqueous solution form, the oxidation methylene radical multipolymer of winding-up before the melting, the melting etc., can adopt any one addition means, as long as in the operation of polymkeric substance being carried out melting treatment, have quaternary ammonium compound.

By using the aforementioned stable method, can obtain simply at short notice considerably less, the thermally-stabilised good and weather stain of unsettled terminal part and be detained the teracol base co-polymer that tint permanence obtains improveing.

The mode of polymerization is not particularly limited, and in order easily to obtain the powder of teracol base co-polymer, is preferably slurry polymerization, mass polymerization.

Polyacetal resin of the present invention is that more than 70% and each time the standard deviation sigma of the fail in tension intensity level of test is the polyacetal resin of the scope of 0≤σ≤10 after carrying out hot water test in 10 days under 130 ℃, based on the conservation rate of the fail in tension intensity of ISO527.

After carrying out hot water test in 10 days under 130 ℃, can confirm by the following method based on the conservation rate of the fail in tension intensity of ISO527: use injection machine to make the ISO dumb-bell test piece, make in its hot water that is immersed in 130 ℃, flood and take out test film after 10 days, measure fail in tension intensity.

It is that 230 ℃, forming period are to obtain under 80 ℃ the molding condition for injection/cooling=30 seconds/15 seconds, die temperature at the barrel design temperature that the test film that uses in the hot water test for example can use injection machine " IS100GN " that Toshiba Machinery Co., Ltd. makes.From the viewpoint of the reliability of hot water test, the thickness of optimization test sheet is more than the 4mm.

Obtain conservation rate by the ratio that carries out the fail in tension intensity before 10 days fail in tension intensity after the hot water test and the hot water test.Need to prove that the mensuration of the fail in tension intensity of the ISO dumb-bell test piece before hot water test begins is carried out according to the condition determination of ISO527, just draw speed is set as 5mm/ minute and measures.

In the tension test after the hot water test, use the test film more than 20 to measure, the mean value of the fail in tension intensity level of employed test film is made as A, standard deviation is made as σ calculates.The number of test film more at most reliability is higher, more preferably more than 30, more preferably more than 50, most preferably carries out the test more than 100.

From the viewpoint of heat aging property, by the mean value A of the fail in tension intensity after the hot water test and the mean value A of the fail in tension intensity before the hot water test ₀The conservation rate of calculating (A ÷ A ₀* 100 (%)) be more than 70%.Be preferably more than 80%, most preferably be more than 90%.

The standard deviation sigma of fail in tension intensity is the scope of 0≤σ≤10.Importantly obtain the higher polyacetal resin of reliability, therefore, standard deviation sigma is preferably the scope of 0≤σ≤7, most preferably is the scope of 0≤σ≤5.

In order to obtain the high polyacetal resin of this reliability, preferably make the content of the magnetic substance metal in the polyacetal resin few.

In the polymerization process of above-mentioned polyacetal resin etc., in polyacetal resin, sneak into sometimes the magnetic substance metal of the works that derives from formation shop equipment etc. that produces because of pipe arrangement burn into wearing and tearing etc. of trace, when the mixed volume of this magnetic substance metal was many, the reliability of polyacetal resin reduced.

The magnetic substance metal ingredient refers at room temperature be the composition of solid matter.Magnetic substance metal finger simple substance, oxide compound, alloy also comprise the magnetic substance metal that is made of two or more elements.For example can enumerate the magnetic substance metal that is consisted of for the element of transition metal by at least a.As above-mentioned magnetic substance metal, can enumerate the magnetic substance metal that contains the Fe element.As the magnetic substance metal that contains the Fe element, can enumerate: the oxide compound in Fe simple substance, Fe source, contain Fe as the alloy iron of composition, contain the mineral of Fe.Can enumerate stainless steel such as: the chromium steel of iron, ferric oxide, fe-cr alloy, the chromium-nickel steel of iron-chromium-nickel alloy, 18% chromium-8% nickel, magnetite, pyrrhotite, ilmenite, rhombohedral iron ore, iron ore, spathic iron ore, arsenopyrite, limonite, pyrite, lepidocrocite, pyrrhosiderite, placer iron etc.

Need to prove that the magnetic substance metal refers to satisfy the metal of χ in the following formula＞0.In addition, χ is susceptibility, is represented by following mathematical expression (6).

χ=M/H …(6)

In the above-mentioned mathematical expression (6), M is the magnetic moment of per unit volume, and H is magnetic field.

The content of the magnetic substance metal in the preferred polyacetal resin is below the 1ppm.Surpass 1ppm and contain sometimes, it is large that the standard deviation of hot water test back draft strength at break becomes, and reliability reduces sometimes.In addition, when the content of magnetic substance metal surpassed 1ppm, a part produced the nido cavity in the test film after the hot water test, and fail in tension intensity is significantly reduced.Infer the nido cavity be the adjacent magnetic substance metal that in test film, exists near generation, high and produce in the situation in nido cavity the fail in tension strength decreased at the content of magnetic substance metal.Need to prove, observe in a part in the situation in nido cavity, need to increase the mensuration number of test film.

From the higher viewpoint of reliability, more preferably the content of magnetic substance metal is below the 0.5ppm, most preferably to be below the 0.1ppm, and preferred maximum width is that the above magnetic substance metal of 150 μ m is below 0.1 in every 1kg polyacetal resin.

In the polyacetal resin of present embodiment, be adjusted to method below the 1ppm as the content with the magnetic substance metal, can enumerate following method: (1) makes polyacetal resin contact the method for processing with strong acid; (2) utilize magnetic force the magnetic substance metal in the polyacetal resin to be carried out the method for separating treatment; Deng.

(1) with the processing that contacts of strong acid

The method is the method that the polyacetal resin that obtains by aforesaid method is contacted with strong acid.As strong acid, can enumerate: hydrochloric acid, nitric acid, sulfuric acid, chloroazotic acid etc.Particularly, can enumerate the method that strong acid that concentrated hydrochloric acid and concentrated nitric acid are mixed with the ratio of mixture of 3:1 ~ 1:3 contacts with polyacetal resin.

At least filter after contacting more than 1 minute, fully make its drying after the washing, the content that obtains thus the magnetic substance metal is the following polyacetal resin of 1ppm.Although also depend on the concentration of acid, contact makes polyacetal resin decompose sometimes for a long time.

(2) magnetic separating is processed

The method is to utilize magnetic force (magnetic force generation source) with the method for polyacetal resin with the magnetic substance metal separation that contains.Particularly, be following method: polyacetal resin is passed through, utilize magnetic force with polyacetal resin and magnetic substance metal separation in the magnet separator of regulation.

As mentioned above, polyacetal resin of the present invention can obtain by following method: the powder that obtains polyacetal by above-mentioned polymerization process, the powder that makes polyacetal in possessing magnetic force and produce the magnet separator in source by and the magnetic substance metal in the polyacetal is removed, the content that makes thus the magnetic substance metal is below the 1ppm.

The polyacetal resin that passes through in magnet separator need to be powder shaped.The polyacetal resin that obtains by above-mentioned polymerization process be shaped as the different shapes such as powder shaped, particulate state, obtaining with particulate state in the situation of polyacetal resin, can utilize pulverizer etc. to make powder shaped.In the magnet separator in the magnetic force generation source that possesses regulation, pass through as described later by the polyacetal resin that makes powder shaped, can control the content of magnetic substance metal with high efficient.Because polyacetal resin is powder shaped, therefore, the micro mist of magnetic substance metal is present in outside the polyacetal resin powder, thereby can controls the content of magnetic substance metal with high efficient.

In this situation, the volume average particle size of preferred polyacetal resin powder is below the 3mm.Although also depend on size-grade distribution, the size of powder can be stopped up magnet separator during greater than 3mm, is difficult to obtain enough treatment capacities, thereby is difficult to carry out efficient treatment process.More preferably volume average particle size is below the 2mm, and further the preferred volume median size is below the 1mm.

The particle of polyacetal resin is less, and loose apparent specific gravity described later tends to lower, and but then, the efficient of removing of small magnetic substance metal improves.On the other hand, when increasing particle diameter from the viewpoint of the treatability that improves powder, small magnetic substance metal remove Efficiency Decreasing.Therefore, from both balances, the volume average particle size of preferred polyacetal resin particle is the scope of 0.05mm ~ 2mm, more preferably the scope of 0.1mm ~ 1mm, the more preferably scope of 0.15mm ~ 1mm.

For the measuring method of volume average particle size, for example, can be with polyacetal resin powder " dispersion " in water or methyl alcohol, the laser diffraction particle size analyzer SALD3100 that then uses Shimadzu Seisakusho Ltd. to make measures.

(loose apparent specific gravity)

It is powder more than 0.4 that the polyacetal resin of present embodiment is preferably loose apparent specific gravity.Thus, make handling efficiency, the metering when polyacetal resin is processed and the treatability of powder when carrying in the container of clogging regulation reach good.Loose apparent specific gravity is more preferably more than 0.45, more preferably more than 0.50, further more preferably more than 0.55.It is that 100 milliliters metal vessel is measured that loose apparent specific gravity can utilize powder characteristic tester (ホ ソ カ ヮ ミ Network ロ ソ company make, powder characteristic tester PT-E type) to use volume.

Pass through in the magnet separator that possesses magnetic force generation source by the polyacetal resin that makes powder shaped, can utilize magnetic force with polyacetal resin and magnetic substance metal separation, thereby the magnetic substance metal in the polyacetal is removed.

Produce the magnet separator in source as possessing magnetic force, can use to have and dispose the magnet separator of formation that magnetic force produces the regulation path in source, can enumerate such as the electromagnetic separator that the magnetic force catcher (マ ヅ ッ Network キ ャ ッ チ) that the magnetic separator that ダ ィ カ Co., Ltd. makes, the ヅ ェ ィ ェ of Co., Ltd. system ァ ィ make, Japanese マ グ ネ テ ィ Network ス make etc.

By polyacetal resin is passed through in the magnet separator that possesses magnetic force generation source, contained magnetic substance metal is adsorbed on the magnetic force generation source in the polyacetal resin, thereby can control the content of magnetic substance metal.

Produce the source as above-mentioned magnetic force, have: permanent magnet, electro-magnet, the viewpoint from the recovery easness of the intensity of magnetic force, magnetic substance metal is preferably electro-magnet.

Produce the magnetic force in source as above-mentioned magnetic force, make that the magnetic force of polyacetal resin by magnetized spot in the zone of removing the magnetic substance metal is higher then more can remove the magnetic substance metal efficiently, this regional magnetic force is preferably more than 0.6 tesla, more preferably more than 0.8 tesla, more preferably more than 0.9 tesla, further more preferably more than 1.2 teslas, further be preferably more than 1.6 teslas.

By polyacetal resin is passed through in the magnetized area that is produced by above-mentioned magnetic force generation source, the magnetic substance metal is adsorbed.

As the method that polyacetal resin is supplied in the magnet separator, different because of the structure of magnet separator, can enumerate such as: use to have the path of regulation and in this path, to possess magnetic force to produce the magnet separator in source, supply with polyacetal resin and make the free-falling method of polyacetal resin etc. from top to this path.

In addition, the shape in magnetic force generation source can be the arbitrarily shape such as round shape, coil shape.

For example, as magnet separator, can use the magnet separator with following formation: be provided with the generation of columnar magnetic field and use coil, and in this cylindrical body, be provided with the magnetic substance strainer of slit-shaped.

The magnetic field that above-mentioned magnetic substance strainer produces because of coil produces the source with magnetic force thereby become magnetic force.

The interval that magnetic force that polyacetal resin passed through produces the source is the various intervals by the gap such as being spaced apart of the magnetic substance strainer grid that consists of the magnetic substance strainer, slit, coarse thread, the viewpoint of removing efficient from the magnetic substance metal, be preferably below the 15mm, more preferably below the 10mm, more preferably below the 7mm, further more preferably below the 5mm.

In addition, the shape that magnetic force produces the source is not limited to the aforesaid formation that is provided with the magnetic substance strainer of slit-shaped in cylindrical body, also can be that the tubulose that the zone passed through at polyacetal resin does not arrange the magnetic substance strainer of slit-shaped consists of.In this situation, be equivalent to magnetic force in the cylindrical body and produce the source, the caliber of this cylinder is equivalent to the interval that above-mentioned magnetic force produces the source.

From removing efficiently the viewpoint of magnetic substance metal, the quantity of preferred magnetic substance strainer is more than 10, more preferably more than 12, more preferably more than 15.

The magnetic substance strainer can be any in reticulation, slit-shaped, the coarse thread shape.

By after in above-mentioned coil, passing into electric current and producing magnetic field, polyacetal resin is imported in the cylinder, the magnetic substance metal ingredient is adsorbed on the magnetic substance strainer, thereby can be removed.

In the path that polyacetal resin is passed through, preferred magnetic force effectively plays a role and the length in the zone that the magnetic substance metal that contains in the polyacetal resin can be removed is that magnetic force effective separation length adds up to more than the 100mm.By magnetic force effective separation length is added up to more than the 100mm, can remove efficiently the magnetic substance metal.Magnetic force effective separation length is more preferably more than the 110mm, more preferably more than the 120mm.

Carrying out in retrofit or the thin molded situation, the viewpoint of the viewpoint of destroying from obstruction, cob webbing, the mould that suppresses molding die and the defective when suppressing to form diaphragm, in the polyacetal resin of preferred present embodiment maximum width be the content of the above magnetic substance metal of 150 μ m be 0.1/below the kg.

Whether the maximum width of magnetic substance metal is can be that the sieve (net) of 150 μ m is confirmed by sieve aperture by judging the magnetic substance metal more than the 150 μ m.

Particularly, polyacetal resin is dissolved in the hexafluoroisopropanol, utilizes separating centrifuge to make the magnetic substance precipitated metal, supernatant discarded makes the magnetic substance metal be dispersed in the hexafluoroisopropanol again, utilizes separating centrifuge to make the magnetic substance precipitated metal.Repeatedly should operate, and magnet was made the magnetic substance metal separation near the bottom of outside of containers.After the magnetic substance metal that obtains like this carried out drying treatment, be the sieve of 150 μ m with above-mentioned sieve aperture, calculate the number of the unsanctioned magnetic substance metal of per unit weight.

More preferably maximum width be the above magnetic substance metal content of 100 μ m be 0.1/below the kg, further preferred maximum width be the above magnetic substance metal content of 50 μ m be 0.1/below the kg.

Maximum width is that the content of the above magnetic substance metal of 150 μ m is that the following polyacetal resin of 0.1/kg can obtain by aforesaid method (method that polyacetal resin is contacted with strong acid), (polyacetal resin is carried out the method that magneticseparation is processed).

In the scope of not damaging effect of the present invention, can in polyacetal resin of the present invention, add separately or make up additive such as the thermo-stabilizer that uses in the polyacetal resin that adds in the past, weather-proof (light) stablizer, releasing agent etc.

As thermo-stabilizer, the effectively trapping agent of antioxidant, formaldehyde or formic acid or their combination.As antioxidant; preferred hindered phenol anti-oxidants; for example can enumerate: Octadecane base-3-(3 '; 5 '-di-t-butyl-4 '-hydroxyphenyl) propionic ester; Octadecane base-3-(the 3 '-methyl-5-tertiary butyl-4 '-hydroxyphenyl) propionic ester; n-tetradecane base-3-(3 '; 5 '-di-t-butyl-4 '-hydroxyphenyl) propionic ester; 1; (3-(3 for 6-hexylene glycol-two; 5-di-t-butyl-4-hydroxyphenyl) propionic ester); 1; (3-(3 for 4-butyleneglycol-two; 5-di-t-butyl-4-hydroxyphenyl) propionic ester); triethylene glycol-two (3-(the 3-tertiary butyl-5-methyl-4-hydroxyphenyl) propionic ester); four (methylene radical-3-(3 '; 5 '-di-t-butyl-4 '-hydroxyphenyl) propionic ester) methane; 3; two (the 2-(3-(3-tertiary butyl-4-hydroxy-5-aminomethyl phenyl) propionyloxy)-1 of 9-; the 1-dimethyl ethyl) 2; 4; 8; 10-four oxaspiros (5; 5) undecane; N; N '-two-3-(3 '; 5 '-di-t-butyl-4-hydroxyphenyl) propionyl hexamethylene-diamine; N; N '-tetramethylene is two-3-(3 '-methyl-the 5 '-tertiary butyl-4-hydroxyphenyl) propionyl diamines; N; N '-two-(3-(3; 5-di-t-butyl-4-hydroxyphenyl) propionyl) hydrazine; N-salicyloyl-N '-salicylidene hydrazine; 3-(N-salicylyl) amino-1; 2; the 4-triazole; N; N '-two (2-(3-(3,5-dibutyl-4-hydroxyphenyl) propionyloxy) ethyl) oxyamide etc.

In the above-mentioned hindered phenol anti-oxidants, preferred triethylene glycol-two-(3-(the 3-tertiary butyl-5-methyl-4-hydroxyphenyl) propionic ester), four (methylene radical-3-(3 ', 5 '-di-t-butyl-4 '-hydroxyphenyl) propionic ester) methane.

As the trapping agent of formaldehyde or formic acid, can enumerate: oxyhydroxide, inorganic acid salt, carboxylate salt and the alkoxide etc. that (I) contain formaldehyde reaction nitrogen compound and polymkeric substance, (II) basic metal or alkaline-earth metal.Contain the formaldehyde reaction nitrogen compound as (I), can enumerate: (1) Dyhard RU 100, (2) amino triazine that replaces, (3) amino triazine that replaces and the cocondensation compound of formaldehyde etc.As (2) the amino triazine that replaces, for example have: guanamines (2,4-diamino s-triazine), trimeric cyanamide (2,4, the 6-tri-amino-p-triazine), the N-melamine-butyl, N phenyl melamine, N, N-phenylbenzene trimeric cyanamide, N, N-diallyl trimeric cyanamide, N, N '; N "-triphenyl trimeric cyanamide, the N-melamine methylol, N, N '-dihydroxymethyl trimeric cyanamide, N, N '; N "-trimethylol melamine, benzoguanamine (2,4-diamino-6-phenyl s-triazine), 2,4-diamino-6-methyl s-triazine, 2,4-diamino-6-butyl s-triazine, 2,4-diamino-6-benzyloxy s-triazine, 2,4-diamino-6-butoxy s-triazine, 2,4-diamino-6-cyclohexyl s-triazine, 2,4-diamino-6-chloro-s-triazine, 2,4-diamino-6-sulfydryl s-triazine, 2, the amino s-triazine (cyanuramide) of 4-dioxo-6-, 2-oxo-4,6-diamino s-triazine (cyanurodiamide), N, N ', N '-four cyanoethyl benzoguanamine etc.As (3) amino triazine that replaces and the cocondensation compound of formaldehyde, such as having: melamine-formaldehyde condensation products etc.Wherein, preferred Dyhard RU 100, trimeric cyanamide and melamine-formaldehyde condensation products.

In addition, have the polymkeric substance of formaldehyde reaction nitrogen base as (I), can be: (1) polyamide resin, (2) acrylamide and derivative thereof or acrylamide and derivative thereof and other vinyl monomers be the polymerization and polymkeric substance, (4) amine, acid amides, urea and the carbamate etc. that obtain contain the polymkeric substance of nitrogen base in the presence of radical polymerization of polymerization and the polymkeric substance, (3) acrylamide and the derivative thereof that obtain or acrylamide and derivative thereof and other vinyl monomers in the presence of metal alkoxide.As the polyamide resin of (1), can enumerate: nylon 4-6, nylon 6, nylon 6-6, nylon 6-10, nylon 6-12, nylon 12 etc. and their multipolymer such as nylon 6/6-6, nylon 6/6-6/6-10, nylon 6/6-12 etc.As the polymerization and the polymkeric substance that obtains can be enumerated poly--Beta-alanine multipolymer in the presence of metal alkoxide of (2) acrylamide and derivative thereof or acrylamide and derivative thereof and other vinyl monomers.Above-mentioned polymkeric substance can be made by the method for putting down in writing in Japanese JP 6-12259 number, Japanese JP 5-87096 number, Japanese JP 5-47568 number and Japanese kokai publication hei 3-234729 number each communique.Make as (3) acrylamide and derivative thereof or acrylamide and derivative thereof and other vinyl monomers method that polymerization and the polymkeric substance that obtains are put down in writing in can be by Japanese kokai publication hei 3-28260 communique in the presence of radical polymerization.

As oxyhydroxide, inorganic acid salt, carboxylate salt and the alkoxide of (II) basic metal or alkaline-earth metal, can enumerate such as oxyhydroxide, the carbonate of this metal, phosphoric acid salt, silicate, borate, the carboxylate salt of sodium, potassium, magnesium, calcium or barium etc.The carboxylic acid of this carboxylate salt is for to have the saturated of 10 ~ 36 carbon atoms or unsaturated aliphatic carboxylic acid etc., and above-mentioned carboxylic acid can be replaced by hydroxyl.As representative examples of saturated aliphatic carboxylic, can enumerate: capric acid, lauric acid, tetradecanoic acid, palmitinic acid, stearic acid, eicosanoic acid, docosoic, lignoceric acid, cerinic acid, montanic acid, myricyl acid, ceroplastic scid.The unsaturated aliphatic carboxylic acid can be enumerated: undecylenic acid, oleic acid, elaidic acid, cetoleic acid, erucic acid, brassidic acid, Sorbic Acid, linolic acid, linolenic acid, arachidonic acid, propynoic acid, stearolic acid etc.In addition, as alkoxide, can enumerate methylate, ethylate of above-mentioned metal etc.

As weather-proof (light) stablizer, preferred (I) benzotriazole category material, (II) oxanilide class material and (III) hindered amines material.As (I) benzotriazole category material, for example can enumerate: 2-(2 '-hydroxyl-5 '-aminomethyl phenyl) benzotriazole, 2-[2 '-hydroxyl-3, the 5-di-tert-butyl-phenyl) benzotriazole, 2-[2 '-hydroxyl-3,5-diisoamyl phenyl) benzotriazole, 2-[2 '-hydroxyl-3, two (the α of 5-, α-dimethylbenzyl) phenyl]-the 2H-benzotriazole, 2-(2 '-hydroxyl-4 '-octyloxyphenyl) benzotriazole etc., be preferably 2-[2 '-hydroxyl-3, two (the α of 5-, α-dimethylbenzyl) phenyl]-the 2H-benzotriazole, 2-[2 '-hydroxyl-3, the 5-di-tert-butyl-phenyl) benzotriazole.

As (II) oxanilide class material, can enumerate such as 2-oxyethyl group-2 '-ethyl oxalyl pentanoic, the 2-oxyethyl group-5-tertiary butyl-2 '-ethyl oxalyl pentanoic, 2-oxyethyl group-3 '-dodecyl oxalyl pentanoic etc.Above-mentioned substance can use separately separately, also can be used in combination of two or more.

As (III) hindered amines material, can enumerate: 4-acetoxyl group-2,2,6,6-tetramethyl piperidine, 4-stearoyl-oxy-2,2,6,6-tetramethyl piperidine, 4-acryloxy-2,2,6, the 6-tetramethyl piperidine, 4-(phenylacetyl oxygen base)-2,2,6, the 6-tetramethyl piperidine, 4-benzoyloxy-2,2,6,6-tetramethyl piperidine, 4-methoxyl group-2,2,6,6-tetramethyl piperidine, the stearic oxygen base-2,2 of 4-, 6, the 6-tetramethyl piperidine, 4-cyclohexyloxy-2,2,6, the 6-tetramethyl piperidine, 4-benzyloxy-2,2,6,6-tetramethyl piperidine, 4-phenoxy group-2,2,6,6-tetramethyl piperidine, 4-(ethyl carbamoyloxy group)-2,2,6, the 6-tetramethyl piperidine, 4-(cyclohexyl carbamoyloxy group)-2,2,6, the 6-tetramethyl piperidine, 4-(phenylamino methanoyl)-2,2,6,6-tetramethyl piperidine, two (2,2,6,6-tetramethyl--4-piperidines) carbonic ether, two (2,2,6,6-tetramethyl--4-piperidyl) barkite, two (2,2,6,6-tetramethyl--4-piperidyl) malonic ester, two (2,2,6,6-tetramethyl--4-piperidyl) sebate, two (2,2,6,6-tetramethyl--4-piperidyl) adipic acid ester, two (2,2,6,6-tetramethyl--4-piperidyl) terephthalate, 1,2-two (2,2,6,6-tetramethyl--4-piperidines oxygen base) ethane, α, α '-two (2,2,6,6-tetramethyl--4-piperidines oxygen base) p-Xylol, two (2,2,6,6-tetramethyl--4-piperidyl) Toluene-2,4-diisocyanate, the 4-diurethanes, two (2,2,6,6-tetramethyl--4-piperidyl) hexa-methylene-1, the 6-diurethanes, three (2,2,6,6-tetramethyl--4-piperidyl) benzene-1,3,5-tricarboxylic ester, three (2,2,6,6-tetramethyl--4-piperidyl) benzene-1,3,4-tricarboxylic ester etc., be preferably two (2,2,6,6-tetramethyl--4-piperidyl) sebate.Above-mentioned hindered amines material can use separately separately, also can be used in combination of two or more.In addition, the most preferably combination of above-mentioned benzotriazole category material, oxanilide class material and hindered amines material.

As releasing agent, can enumerate: ester, the silicone oil of the ester of alcohol and alcohol and lipid acid, alcohol and dicarboxylic acid.

As alcohol, monohydroxy-alcohol, polyvalent alcohol are arranged, as the example of monohydroxy-alcohol, for example can enumerate: octanol, octanol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, tridecanol, tetradecyl alcohol, pentadecanol, hexadecanol, heptadecyl alcohol, stearyl alcohol, oleyl alcohol, nonadecanol, eicosanol, behenyl alcohol, hexacosyl alcohol, triacontanol, 2-hexyl decyl alcohol, 2-octyl dodecanol, 2-decyl tetradecyl alcohol, outstanding Buddhist nun's Courlene (ユ ニ リ ソ) alcohol.As polyvalent alcohol, for containing the polyvalent alcohol of 2 ~ 6 carbon atoms, for example can enumerate: ethylene glycol, Diethylene Glycol, triethylene glycol, propylene glycol, dipropylene glycol, butyleneglycol, pentanediol, hexylene glycol, glycerine, two glycerine, triglycerin, threitol, erythritol, tetramethylolmethane, arabitol, ribitol, Xylitol, Sorbitol Powder, anhydrous sorbitol, sorbyl alcohol, N.F,USP MANNITOL.

As the ester of alcohol with lipid acid, have: be preferably selected from the lipid acid in palmitinic acid, stearic acid, docosoic, the montanic acid in the fatty acid cpds and be selected from the fatty acid ester that the polyol derivative in glycerine, tetramethylolmethane, anhydrous sorbitol, the sorbyl alcohol forms.Above-mentioned fatty acid ester compound can have hydroxyl, also can not have hydroxyl.Without any restriction.For example, can be monoesters, also can be diester, three esters.In addition, also can hydroxyl be sealed with boric acid etc.

If want the preferred fatty acid ester of illustration, then have: monopalmitin, glycerol-1,3-dipalmitate, tripalmitin, glyceryl monostearate, distearin, Tristearoylglycerol Dan docosoic glyceryl ester Er docosoic glyceryl ester San docosoic glyceryl ester, single montanic acid glyceryl ester, two montanic acid glyceryl ester, three montanic acid glyceryl ester, single pentaerythritol tetrapalmitate, two pentaerythritol tetrapalmitates, three pentaerythritol tetrapalmitates, four pentaerythritol tetrapalmitates, the Stearinsaeure pentaerythritol ester, distearyl acid pentaerythritol ester, three stearic acid pentaerythritol esters, pentaerythritol tetrastearate Dan docosoic pentaerythritol ester Er docosoic pentaerythritol ester San docosoic pentaerythritol ester Si docosoic pentaerythritol ester, single montanic acid pentaerythritol ester, two montanic acid pentaerythritol esters, three montanic acid pentaerythritol esters, four montanic acid pentaerythritol esters, the anhydrous sorbitol monopalmitate, the anhydrous sorbitol dipalmitate, the anhydrous sorbitol tripalmitate, sorbitan monostearate, the anhydrous sorbitol SUNSOFT Q-182S, the anhydrous sorbitol tristearate, anhydrous sorbitol Dan docosoic ester, anhydrous sorbitol Er docosoic ester, anhydrous sorbitol San docosoic ester, anhydrous sorbitol list montanate, anhydrous sorbitol two montanates, anhydrous sorbitol three montanates, the sorbyl alcohol monopalmitate, the sorbyl alcohol dipalmitate, the sorbyl alcohol tripalmitate, sorbitol monostearate, the sorbyl alcohol SUNSOFT Q-182S, the sorbyl alcohol tristearate, sorbyl alcohol Dan docosoic ester, sorbyl alcohol Er docosoic ester, sorbyl alcohol San docosoic ester, sorbyl alcohol list montanate, sorbyl alcohol two montanates, sorbyl alcohol three montanates.

In addition, as with the aliphatic ester compound with the hydroxyl sealing such as boric acid, can also enumerate the boric acid ester of monoglyceride.Alcohol is as pure methyl alcohol with the ester of dicarboxylic acid, ethanol, propyl alcohol, propyl carbinol, isopropylcarbinol, the trimethyl carbinol, Pentyl alcohol, the 2-amylalcohol, n-Heptyl alcohol, n-Octanol, nonanol-, lauryl alcohol, tetradecyl alcohol, hexadecanol, stearyl alcohol, behenyl alcohols etc. are saturated/unsaturated alcohol and oxalic acid as dicarboxylic acid, propanedioic acid, succsinic acid, pentanedioic acid, hexanodioic acid, pimelic acid, suberic acid, nonane diacid, sebacic acid, undecane diacid, undecane dicarboxylic acid, toxilic acid, fumaric acid, the monoesters of propene dicarboxylic acid etc., diester.

As the manufacture method of polyacetal resin composite of the present invention, can make by carrying out melting mixing with the single shaft with ventilation hole or biaxial extruder.

Embodiment

Below, at length the present invention will be described to enumerate specific embodiment and comparative example, but the present invention is not subjected to the restriction of following examples.

The measuring method of various characteristics is as follows among the embodiment.

1. the extraction of the magnetic substance metal in the polyacetal resin and the weighing of content

Use 10 liters of vials, polyacetal resin is dissolved in respectively in the excessive hexafluoroisopropanol, then, the magnet of 1.4 teslas is contacted from outside with the bottom of vial, the magnetic substance metal ingredient in the solution is focused on the bottom.Removing liquid also notes not making the magnetic substance metal flow out to the outside.The magnetic substance metal ingredient that remains in the vial is washed 5 times with hexafluoroisopropanol, and drying is 1 hour under 100 ℃, extracts resulting material as the magnetic substance metal and carries out weighing.

With exist not by sieve aperture be the situation of magnetic substance metal of the sieve (net) of 150 μ m be denoted as *;

Be that the situation of magnetic substance metal of the sieve (net) of 150 μ m is denoted as ◎ with not existing not by sieve aperture.

2. the affirmation of the black foreign matter of polyacetal resin

Use polyacetal resin to carry out hot-pressing processing (under the condition of 220 ℃ * 5 minutes * 10MPa), make the test piece of 10 15cm * 15cm * thickness 1mm.10 test pieces are confirmed that the OSL-1 that uses the オ of Co., Ltd. one ッ カ chemistry to make observes, and estimates according to following benchmark by 5 people.

Do not observe the test piece of black foreign matter: ◎

The test piece of black foreign matter average out to below 2: zero

Observe the test piece that the black foreign matter on average surpasses 2: *

3. the volume average particle size of polyacetal resin

Make the polyacetal resin powder " dispersion " that obtains in embodiment described later and the comparative example in water.Then, the laser diffraction particle size analyzer SALD3100 that uses Shimadzu Seisakusho Ltd. to make measures volume average particle size.

4. the loose apparent specific gravity of polyacetal resin

Utilize powder characteristic tester (ホ ソ カ ヮ ミ Network ロ ソ company makes, powder characteristic tester PT-E type), the use volume is that 100 milliliters metal vessel is measured.

5. the evaluation of lock out operation

The polyacetal resin that per hour can carry out the lock out operation more than the 100kg as the high polyacetal resin of lock out operation, is evaluated as ◎.

With the polyacetal resin of lock out operation that per hour can only carry out not enough 100kg as the low polyacetal resin of lock out operation, be evaluated as *.

6. hot water test

Mix 0.15 mass parts calcium stearate and 0.15 mass parts in the polyacetal resin that obtains by following embodiment to 100 mass parts as the nylon 6 that contains the polymkeric substance of formaldehyde reaction nitrogen, 6, using with the 30mm single axle extruding machine of ventilation hole is that 200 ℃, output carry out melting mixing under as 10kg/ hour condition at barrel temperature, makes thus the polyacetal resin particle.The injection machine " IS100GN " that uses Toshiba Machinery Co., Ltd. to make is that 230 ℃, forming period are the rectangular dumb-bell test piece that is configured as thickness 4mm under 80 ℃ the molding condition for injection/cooling=30 seconds/15 seconds, die temperature with the particle of gained at the barrel design temperature.

Condition determination according to ISO527 is measured the fail in tension intensity that hot water test begins front ISO dumb-bell test piece, just draw speed is set as 5mm/ minute and measures.

50 test films are immersed in the container that is set as 130 ℃, after 10 days, take out test film, measure fail in tension intensity.

The mean value of fail in tension intensity level is made as A, standard deviation is made as σ calculates following evaluation of fluctuating.

Situation in the scope of 0≤σ≤5: zero

Situation in the scope of 5＜σ≤10: △

At σ〉situation in 10 the scope: *

The mean value A of the fail in tension intensity of the conservation rate of in addition, fail in tension intensity after by hot water test and the mean value A of the fail in tension intensity before the hot water test ₀Utilize following formula to calculate.

Utilize conservation rate (%)=(A ÷ A ₀* 100) calculate, and following expression:

More than 90%: ◎

More than 70%: △

Less than 70%: *

Polyacetal resin

(POM-A)

The twin shaft self-clean type polymerizer (L/D=8) of jacketed that can be by thermal medium is adjusted to 80 ℃, respectively with 4kg/ hour, 138.2g/ hour add continuously trioxane, as 1 of comonomer, 3-dioxolane (be 4.2 % by mole with respect to 1 mole of trioxane), and to add continuously be 0.1 * 10 as chain-transfer agent with respect to 1 mole of trioxane ^-3The formal of mole.And then, be 2.0 * 10 with respect to 1 mole of trioxane ^-5The boron trifluoride di-n-butyl ether that the amount of mole is added continuously as polymerizing catalyst carries out polymerization.The mode of polymerization is mass polymerization.The powder of the polyacetal resin multipolymer that will be discharged by polymerizer is put in 0.1% triethylamine aqueous solution, makes the polymerizing catalyst inactivation.Use separating centrifuge to filter out the polyacetal resin multipolymer of inactivation, then, add the aqueous solution that 1 mass parts contains the bursine formate (triethyl-2-hydroxyethyl ammonium formate) as quaternary ammonium compound with respect to 100 mass parts polyacetal resin multipolymers, after mixing, at 140 ℃ of dry diels, obtain white polymer.Volume average particle size is about 800 μ m.Loose apparent specific gravity is 0.55.

(POM-B)

Make the paraldehyde that fully dehydrates carry out thermolysis at 150 ℃, and in cold-trap by several times, obtain thus purity and be 99.9% formaldehyde gas.Stir turbine blade and stainless steel baffle plate and possess in the stainless steel polymerization tank of 20 liters of jacketeds of reflux exchanger at the vapor pipe on polymerization tank top to possessing in polymerization tank bottom for the iron atomizer that imports formaldehyde gas, stainless steel, contained 1.0 * 10 with 1800g/ hour to 9000g ^-4Import formaldehyde gas in the hexane of the tetrabutyl ammonium acetate of mol/L.When supplying with formaldehyde, contain 1.0 * 10 per hour to supply with in continuous 7 hours as the ratio of 9000g ^-4The hexane of the tetrabutyl ammonium acetate of mol/L.Formaldehyde gas is also supplied with continuously take the ratio as 9000g per hour, makes during this period polymerization temperature maintain 60 ℃.The mode of polymerization is slurry polymerization.Extract continuously evenly the hexane that contains polymkeric substance out with feed rate, the solution of extracting out is transported in the solid-liquid separating machine spiral decanting vessel continuously by pump, utilize to filter and separate.The polymkeric substance of isolated moisture state is transported to continuously to be possessed stainless steel and stirs turbine blade, stainless steel baffle plate and overflow line and possess in the vapor pipe on polymerization tank top in the rinse bath of 20 liters of jacketeds of reflux exchanger, supplies with continuously acetone take the ratio as 9000g per hour simultaneously.The acetone that will contain polymkeric substance by overflow line is transported in the solid-liquid separating machine spiral decanting vessel continuously, utilizes to filter and separates.The polyacetal resin of resulting moisture state 60 ℃ of lower vacuum-dryings, is obtained white polymer.50 mass parts in the white polymer that obtains are like this mixed with 500 mass parts diacetyl oxides, 0.1 mass parts potassium acetate, heated 3 hours down and cool off at 139 ℃.Then, use acetone that polymkeric substance is fully washed, and carry out drying equally, be recovered to the linear polymer of 49 mass parts polyoxymethylenes.Volume average particle size is about 300 μ m.Loose apparent specific gravity is 0.59.

[magnet separator]

In embodiment described later and the comparative example, use electromagnetic separator (the effective separation length: 380mm) upper magnet separator with the magnetic force variable device of the product CG-180X type by name of making in Japanese マ グ ネ テ ィ ッ Network ス company.

The metal-made screen cloth is not permanent magnet, uses following any one, use the multi-disc screen cloth and when observing from top 45 modes of spending that turn clockwise separately install.

A: bar-shaped screen cloth, sieve aperture 5mm * 20 slice

B: bar-shaped screen cloth, sieve aperture 10mm * 20 slice

Recovery is attached to magnetic substance metal and the weighing on the screen cloth.

Even the magnetic substance metal that the power supply of tripping magnet also is attached on the screen cloth reclaims by pulling down screen cloth and pounding with a hammer, measure content based on above-mentioned (the 1. extraction of the magnetic substance metal in the polyacetal resin and the weighing of content).

(embodiment 1)

Use the above-mentioned electromagnetic separator that possesses screen cloth A that POM-A is carried out lock out operation.

Magneticflux-density is 1.6 teslas, and its speed with about 200kg/ hour is passed through.

The obstruction of screen cloth does not occur, and can process to all-the-time stable.The magnetic substance metal content of resulting polyacetal resin is 0.001ppm.In addition, also unconfirmed to the black foreign matter.To be denoted as POM-1 by the polyacetal resin that this embodiment obtains.

[metal is sneaked into the checking on the impact of polyacetal resin]

In order to verify that the trace of magnetic substance metal that consists of the works of shop equipment etc. because of the deriving from of producing such as pipe arrangement burn into wearing and tearing sneaks into, mix following steel ball as iron powder in the POM-1 that does not contain the magnetic substance metal with amount described later.

(steel ball)

The steel ball that uses the タ of Co., Ltd. Na カ shown below to make.

Sieve by 106 μ m but the steel ball of the sieve by 45 μ m not: steel ball P

Sieve by 150 μ m but the steel ball of the sieve by 106 μ m not: steel ball Q

Sieve by 250 μ m but the steel ball of the sieve by 150 μ m not: steel ball R

(comparative example 1)

Be that the steel ball P of 45 ~ 106 μ m mixes with the above-mentioned POM-1 of 10kg and 0.050g particle diameter, do not utilize the lock out operation of above-mentioned magnet separator and directly carry out the black foreign matter and confirm and hot water test.Evaluation result is shown in Table 1.Need to prove that the steel ball level of residue is by rounding up later the 3rd of radix point to represent.

(comparative example 2)

Be that the steel ball Q of 106 ~ 150 μ m mixes with the above-mentioned POM-1 of 10kg and 0.050g particle diameter, do not utilize the lock out operation of above-mentioned magnet separator and directly carry out the black foreign matter and confirm and hot water test.Evaluation result is shown in Table 1.

(comparative example 3)

Be that the steel ball R of 150 ~ 250 μ m mixes with the above-mentioned POM-1 of 10kg and 0.050g particle diameter, do not utilize the lock out operation of above-mentioned magnet separator and directly carry out the black foreign matter and confirm and hot water test.Evaluation result is shown in Table 1.

(embodiment 2)

Be that the steel ball Q of 106 ~ 150 μ m mixes with the above-mentioned POM-1 of 10kg and 0.050g particle diameter, use the above-mentioned electromagnetic separator that possesses screen cloth A to carry out lock out operation.Magneticflux-density is 1.6 teslas, makes it be about 200kg/ hour speed with treatment rate and passes through.The obstruction of screen cloth does not occur, and can process to all-the-time stable.Evaluation result is shown in Table 1.

(embodiment 3 ~ 6)

According to the condition shown in the table 2, other aspects are implemented similarly to Example 3.Evaluation result is shown in Table 2.

(comparative example 4)

Be that the steel ball R of 150 ~ 250 μ m mixes with the above-mentioned POM-1 of 10kg and 0.050g particle diameter, and in the bag of the polyethylene system of putting into.Then, the adsorbing bar T that magneticflux-density will be housed be 1.25 teslas, diameter and be the bar magnet of 23.5mm in external diameter is the SUS316 tubulation of 25mm is encased in the polyethylene bag, and hand mix 1 minute.

Then, from polyethylene bag, take out adsorbing bar T, then, use polyacetal resin to carry out the black foreign matter and confirm and hot water test.Evaluation result is shown in Table 1.

(comparative example 5)

Except using steel ball P, similarly implement with comparative example 4.Evaluation result is shown in Table 1.

(comparative example 6)

Be to mix 0.15 mass parts calcium stearate and 0.15 mass parts in mixture 100 mass parts of steel ball Q of 106 ~ 150 μ m as the nylon 6 that contains the polymkeric substance of formaldehyde reaction nitrogen to the above-mentioned POM-1 of 10kg and 0.050g particle diameter, 6, using with the 30mm single axle extruding machine of ventilation hole is that 200 ℃, output carry out melting mixing under as 10kg/ hour condition at barrel temperature, makes thus the polyacetal resin particle.The size of particle is the size of 3mm * 3mm.

Use the above-mentioned electromagnetic separator that possesses screen cloth A to carry out lock out operation the particle of gained.Magneticflux-density is 1.6 teslas.

When passing through with 200kg/ hour speed, the obstruction of screen cloth occurs, therefore have to suppress Negotiation speed.The magnetic substance metal content of the polyacetal resin that obtains is 2.90ppm.Evaluation result is shown in Table 1.

Table 1

Among the embodiment 2 ~ 6, the content of magnetic substance metal is few, therefore, and the result who in hot water test, obtains demonstrating high conservation rate and have high reliability.

Do not use magnet separator and utilize bar magnet to carry out having a large amount of not magnetic substance metals of Ex-all in the comparative example 4 and 5 that metal removes, do not obtain practical good result.

In the comparative example 6, utilize particle to carry out lock out operation, thereby the screen cloth perviousness is poor, fails fully to carry out the separation of magnetic substance metal, therefore, do not obtain practical good result.

(embodiment 7)

Except using POM-B, similarly implement with above-described embodiment 1.

The obstruction of screen cloth does not occur, and can process to all-the-time stable.The magnetic substance metal content of the polyacetal resin that obtains is 0.001ppm.In addition, also unconfirmed to the black foreign matter.To be denoted as POM-2 by the polyacetal resin that this embodiment obtains.

(comparative example 7)

Be that the steel ball P of 45 ~ 106 μ m mixes with the above-mentioned POM-2 of 10kg and 0.050g particle diameter, do not utilize the lock out operation of above-mentioned magnet separator and directly carry out the black foreign matter and confirm.Evaluation result is shown in Table 2.Need to prove that the steel ball level of residue is by rounding up later the 3rd of radix point to represent.

(comparative example 8)

Be that the steel ball Q of 106 ~ 150 μ m mixes with the above-mentioned POM-2 of 10kg and 0.050g particle diameter, do not utilize the lock out operation of above-mentioned magnet separator and directly carry out the black foreign matter and confirm.Evaluation result is shown in Table 2.

(comparative example 9)

Be that the steel ball R of 150 ~ 250 μ m mixes with the above-mentioned POM-2 of 10kg and 0.050g particle diameter, do not utilize the lock out operation of above-mentioned magnet separator and directly carry out the black foreign matter and confirm.Evaluation result is shown in Table 2.

(embodiment 8)

Be that the steel ball Q of 106 ~ 150 μ m mixes with the above-mentioned POM-2 of 10kg and 0.050g particle diameter, use the above-mentioned electromagnetic separator that possesses screen cloth A that it is carried out lock out operation.Magneticflux-density is 1.6 teslas, makes it be about 200kg/ hour speed with treatment rate and passes through.The obstruction of screen cloth does not occur, and can process to all-the-time stable.Evaluation result is shown in Table 2.

(embodiment 9 ~ 13)

According to the condition shown in the table 2, other aspects are implemented similarly to Example 8.Evaluation result is shown in Table 2.

(comparative example 10)

Be that the steel ball R of 150 ~ 250 μ m mixes with the above-mentioned POM-2 of 10kg and 0.050g particle diameter, and in the bag of the polyethylene system of putting into.Then, the adsorbing bar T that magneticflux-density will be housed be 1.25 teslas, diameter and be the bar magnet of 23.5mm in external diameter is the SUS316 tubulation of 25mm is encased in the polyethylene bag, and hand mix 1 minute.

Then, from polyethylene bag, take out adsorbing bar T, then, confirm the black foreign matter with polyacetal resin.Evaluation result is shown in Table 2.

(comparative example 11)

Except using steel ball P, similarly implement with comparative example 10.Evaluation result is shown in Table 2.

(comparative example 12)

Be to mix 0.15 mass parts calcium stearate and 0.15 mass parts in mixture 100 mass parts of steel ball Q of 106 ~ 150 μ m as the nylon 6 that contains the polymkeric substance of formaldehyde reaction nitrogen to the above-mentioned POM-2 of 10kg and 0.050g particle diameter, 6, using with the 30mm single axle extruding machine of ventilation hole is that 200 ℃, output carry out melting mixing under as 10kg/ hour condition at barrel temperature, makes thus the polyacetal resin particle.The size of particle is the size of 3mm * 3mm.

Use the above-mentioned electromagnetic separator that possesses screen cloth A to carry out lock out operation the particle of gained.Magneticflux-density is 1.6 teslas.

When passing through with 200kg/ hour speed, the obstruction of screen cloth occurs, therefore have to suppress Negotiation speed.The magnetic substance metal content of the polyacetal resin that obtains is 2.90ppm.Evaluation result is shown in Table 2.

Table 2

Among the embodiment 8 ~ 13, the content of magnetic substance metal is below the 1ppm, therefore as can be known, does not also produce the black foreign matter and has realized high quality.In addition, can carry out lock out operation with 200kg/ hour, obtain the magnetic substance metal by the polyacetal resin of high efficiente callback.

Even the metal separation method of using magnet separator is also can remove the magnetic substance metallics among the embodiment 12 and 13 of steel ball R of 150 ~ 250 μ m using particle diameter, thereby the method is efficient method as can be known.

Do not use magnet separator and utilize bar magnet to carry out having a large amount of not magnetic substance metals of Ex-all in the comparative example 10 and 11 that metal removes, do not obtain practical good result.

In the comparative example 12, utilize particle to carry out lock out operation, therefore, the screen cloth perviousness is poor, fails fully to carry out the separation of magnetic substance metal.

Claims (15)

1. polyacetal resin, its after carrying out hot water test in 10 days under 130 ℃, be more than 70% based on the conservation rate of the fail in tension intensity of ISO527, and the standard deviation sigma of the fail in tension intensity level of test is the scope of 0≤σ≤10 each time.

2. polyacetal resin as claimed in claim 1, wherein, the content of magnetic substance metal is below the 1ppm.

3. polyacetal resin as claimed in claim 1, wherein, the conservation rate of described fail in tension intensity is more than 70%, and standard deviation sigma is the scope of 0≤σ≤5.

4. polyacetal resin as claimed in claim 1, wherein, described polyacetal resin contains at least a above fatty acid metal salt.

5. polyacetal resin as claimed in claim 1, wherein, the conservation rate of described fail in tension intensity is more than 90%, and standard deviation sigma is the scope of 0≤σ≤5.

6. polyacetal resin as claimed in claim 1, wherein, described polyacetal resin is the polyacetal resin multipolymer.

7. the manufacture method of a polyacetal resin comprises:

Obtain the operation of polyacetal resin by polymerization, and

The powder that makes described polyacetal resin in possessing magnetic force and produce the magnet separator in source by and thereby the magnetic substance metal in the polyacetal resin is removed the content that obtains this magnetic substance metal is the operation of the polyacetal resin below the 1ppm.

8. the manufacture method of polyacetal resin as claimed in claim 7, wherein, the volume average particle size of the powder of described polyacetal resin is below the 3mm.

9. the manufacture method of polyacetal resin as claimed in claim 7, wherein, the powder that makes described polyacetal resin described possess in the magnet separator that magnetic force produces the source by the time, the magnetic force in the zone that the magnetic substance metal is removed from the powder of described polyacetal resin is more than 0.6 tesla.

10. the manufacture method of polyacetal resin as claimed in claim 7, wherein, the magnetic force that uses in the described magnet separator produces the source and is electro-magnet.

11. the manufacture method of polyacetal resin as claimed in claim 7 wherein, passes through the powder of described polyacetal resin between the described magnetic force generation source with the arranged spaced below the 15mm.

12. the manufacture method of polyacetal resin as claimed in claim 7, wherein, the magnetic force effective separation length of described magnet separator is more than the 100mm.

13. the manufacture method of polyacetal resin as claimed in claim 7, wherein, the content by magnetic substance metal in the polyacetal resin after the magnet separator is below the 0.1ppm.

14. the manufacture method of polyacetal resin as claimed in claim 7, wherein, in the polyacetal resin after the magnet separator, maximum width be the above magnetic substance metal of 150 μ m be 0.1/below the kg.

15. a polyacetal resin, it obtains by each described method in the claims 7 ~ 14, and the content of magnetic substance metal is below the 1ppm.