JP2005105103A - Method for manufacturing polyacetal copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a polyacetal copolymer soft and excellent in impact resistance by using a simplified but highly versatile technique in the modification of a polyacetal resin by reaction with another polymer. <P>SOLUTION: In this method for manufacturing a polyacetal copolymer, a polyacetal resin (A) obtained by polymerization in the presence of a cationic polymerization catalyst is fused and mixed with a specified substance (B), which for instance is a polymer having an active hydrogen atom in its molecule, without deactivation of the cationic growth end and of the polymerization catalyst. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a polyacetal copolymer that is flexible and excellent in impact resistance. More specifically, a polyacetal copolymer obtained by melting and kneading a polyacetal resin obtained by a cationic polymerization catalyst with a polymer having a specific reactive functional group in a state where the growing terminal of the polymer or the catalyst used is active. It relates to the manufacturing method.

  Polyacetal resin has excellent balance of mechanical properties, chemical resistance, slidability, etc. and is easy to process, so it is a representative engineering plastic mainly for electric / electronic, automobile and other various mechanical parts. As widely used. In recent years, in addition to conventional injection molding applications, plasticity is added and copolymerization is modified to reduce crystallization speed and crystallinity, improving workability to films, sheets, fibers, etc., and increasing toughness. Many attempts have been made.

  Among them, as an attempt to increase the toughness of the polyacetal resin, many examples have been disclosed in which other polymer chains are introduced into the polymer chain constituting the polyacetal resin to obtain a block copolymer.

  For example, Patent Document 1 proposes that a block copolymer of polyacetal is obtained by polymerizing formaldehyde in the presence of a polymer such as polytetramethylene glycol and vinyl acetate copolymer. However, although this block copolymer has a slightly improved toughness, the strength is remarkably lowered.

  Patent Document 2 describes a production method in which formaldehyde is polymerized on an elastomer having two functional groups selected from a hydroxyl group, a carboxyl group, and an amino group at the terminal. However, such block formation by polymerization is a polymerization by chain transfer to a reactive functional group due to the long reaction time due to the reactivity with the elastomer component, so there is also a problem such as a low molecular weight of the produced polymer. Is expected to be difficult to control. This publication also describes a process for producing a blocked polyacetal in which an elastomer having a reactive functional group is introduced by reaction together with polyoxymethylene and a cyclic ether. However, as far as the examples are concerned, a solvent is used in the reaction, which is not a simple and low-cost method, and its feasibility is low. Furthermore, although a reaction in a non-solvent system is also assumed, there is no description of how to react, including examples, and details are not clear.

  Patent Document 3 further describes a process for producing stabilized polyoxymethylene by reacting polyoxymethylene and polyalkylene oxide under a Lewis acid catalyst. This method can be used for both solvent and non-solvent systems, but it requires a new addition of Lewis acid in the reaction with polyoxymethylene, and it is undeniable that an excessive catalyst causes a decrease in molecular weight during the reaction. . In addition, this publication intends to stabilize the polymer and does not mention any change in mechanical properties due to the reaction.

Patent Document 4 describes a method for producing a polyoxymethylene-polyurethane alloy, and Patent Document 5 describes a grafting of a functional compound onto a functional oxymethylene polymer skeleton using a diisocyanate coupling agent. However, these are cases where isocyanate is used as a reactant. Although isocyanate is highly reactive and exhibits an excellent effect as a reactive agent in polymer modification, it has recently been apt to be avoided as an environmentally hazardous substance, and a technique that does not use an isocyanate compound is desired.
Japanese Patent Publication No. 35-2194 Japanese Examined Patent Publication No. 62-020203 Japanese Patent Publication No. 61-053369 JP-A-7-242724 JP-A-3-21624

  In view of the prior art as described above, the present invention provides a flexible and impact resistant polyacetal resin that is superior in flexibility and impact resistance in a modification method based on reaction with a polymer. The object is to produce a polyacetal copolymer.

  As a result of intensive studies to achieve the above object, the present inventors have melt-kneaded a polyacetal resin obtained by cationic polymerization with a polymer or compound having a specific reactive functional group before undergoing a quenching step. As a result, it was found that desired polymer modification can be performed without adding a solvent, a reactant, and a catalyst / initiator for promoting the reaction, and the present invention has been completed.

  That is, the present invention provides the polyacetal resin (A) obtained by polymerizing with a cationic polymerization catalyst, without subjecting the cation growth terminal and the polymerization catalyst to inactivation treatment (B-1) to (B -4). A method for producing a polyacetal copolymer, which is melt-kneaded with a substance (B) selected from 4).

B-1: Polymer having an active hydrogen atom in the molecule B-2: Polymer having a glycidyl group in the molecule B-3: An aliphatic polyether having a hydroxyl group in the molecule or an aliphatic polyester having a hydroxyl group in the molecule , A polymer obtained by formalization B-4: a compound obtained by formalizing an alkyl monool having 6 or more carbon atoms or an alkylene diol having 6 or more carbon atoms

Hereinafter, the manufacturing method of the polyacetal copolymer of this invention is demonstrated in detail. In the production of the polyacetal copolymer in the present invention, the polyacetal resin (A) serving as the substrate is a polymer compound having an oxymethylene unit (—CH ₂ O—) as a main structural unit, and is a cationic polymerization catalyst. As long as it is manufactured using a polyacetal homopolymer, it may be a polyacetal copolymer containing other comonomer units in addition to an oxymethylene group. In addition, the polyacetal resin (A) may have a branched structure as well as a linear structure, or may have a crosslinked structure. The degree of polymerization is not particularly limited as long as it can be melt processed.

When the polyacetal resin (A) serving as the substrate is a polyacetal copolymer, the comonomer units constituting the copolymer include oxyalkylene units having about 2 to 6 carbon atoms, such as oxyethylene groups (—CH ₂ CH ₂ O—), oxy A propylene group, an oxytetramethylene group and the like are included. The content of the comonomer unit needs to be an amount that does not significantly impair the crystallinity of the polyacetal resin (A). For example, with respect to 100 mol of oxymethylene units that are main constituent units of the polyacetal resin (A). 0.01 to 20 mol, preferably 0.03 to 10 mol, more preferably 0.1 to 5 mol. Such a polyacetal copolymer is obtained by using a cationic polymerization catalyst comprising trioxane (a-1) and a cyclic ether compound (a-2) selected from ethylene oxide, 1,3-dioxolane, 1,4-butanediol formal and diethylene glycol formal. It is convenient and preferable to obtain by copolymerization.

  Moreover, when the polyacetal resin (A) used as a base is a polyacetal homopolymer, such a homopolymer can be obtained by homopolymerizing trioxane or tetraoxane, which is a cyclic oligomer of formaldehyde, using a cationic polymerization catalyst.

  Cationic polymerization catalysts used for the production of the polyacetal resin (A) as described above include lead tetrachloride, tin tetrachloride, titanium tetrachloride, aluminum trichloride, zinc chloride, vanadium trichloride, antimony trichloride, pentafluoride. Phosphorus, antimony pentafluoride, boron trifluoride, boron trifluoride diethyl etherate, boron trifluoride dibutyl etherate, boron trifluoride dioxanate, boron trifluoride acetate anhydrate, boron trifluoride triethylamine complex Boron trifluoride coordination compounds such as compounds, inorganic and organic acids such as perchloric acid, acetyl perchlorate, t-butyl perchlorate, hydroxyacetic acid, trichloroacetic acid, trifluoroacetic acid, p-toluenesulfonic acid, triethyloxonium Tetrafluoroborate, triphenylmethylhexa Rollo antimonate, allyl diazonium hexafluorophosphate, complex salt compounds such as allyl diazonium tetrafluoroborate, diethyl zinc, triethyl aluminum, alkali metal salts such as diethyl aluminum chloride, heteropoly acid and isopoly acid. Among these, three compounds such as boron trifluoride, boron trifluoride diethyl etherate, boron trifluoride dibutyl etherate, boron trifluoride dioxanate, boron trifluoride acetate anhydrate, boron trifluoride triethylamine complex compound, etc. Boron fluoride coordination compounds are preferred. In the polymerization, a molecular weight modifier can also be used.

  The present invention provides a polyacetal resin (A) obtained by polymerization using a cationic polymerization catalyst as described above, without subjecting the cation growth terminal and the deactivation treatment of the polymerization catalyst to a specific substance described below ( It is a method for producing a polyacetal copolymer characterized by being melt-kneaded and reacted with B).

  In the production of ordinary polyacetal resins that are commercially available, a basic compound is added immediately after polymerization to a polymer obtained by polymerization using a cationic polymerization catalyst, or the polymer is added to an aqueous solution thereof. The catalyst and the cation-proliferating terminal of the polymer are deactivated (quenched), and further processed through a stabilization process. In the present invention, the cation-proliferating terminal of the polymer is reacted in the presence of a catalyst that retains activity. The specific substance (B) having a functional functional group is further reacted under melting.

  The polyacetal resin (A) in which the catalyst and the like are active in the reaction is either flaky obtained by polymerization, or in the form of pellets once melt-kneaded together with an antioxidant represented by hindered phenols. It may be a thing. In order to maintain the activity of the catalyst in a more favorable state, it is necessary to avoid contact / mixing with the basic component that causes deactivation of the catalyst until melt-kneading with the substance (B) having a reactive functional group. There is.

  In the present invention, the substance (B) to be melt kneaded and reacted with the polyacetal resin (A) is selected from the following polymers and compounds.

B-1: Polymer having an active hydrogen atom in the molecule B-2: Polymer having a glycidyl group in the molecule B-3: An aliphatic polyether having a hydroxyl group in the molecule or an aliphatic polyester having a hydroxyl group in the molecule Polymer obtained by formalization B-4: Compound obtained by formalizing alkyl monool having 6 or more carbon atoms or alkylene diol having 6 or more carbon atoms Melting with polyacetal resin (A) in non-quenched state The polymer (B-1) to be kneaded may be a polymer having an active hydrogen atom in the molecule, and mainly includes a hydroxyl group, a carboxyl group, an amino group, and a mercapto group as reactive functional groups having an active hydrogen atom. can give. The polymer (B-1) is preferably a bifunctional polymer having such reactive functional groups having active hydrogen atoms at both ends. In consideration of the reactivity with the polyacetal resin (A) obtained by cationic polymerization, the reactive functional group of the polymer (B-1) is preferably a hydroxyl group.

The molecular skeleton of the polymer (B-1) is preferably a soft segment component that can be an elastomer, such as an alkylene glycol unit, a polyester containing an aliphatic alkyl unit, or a polyether. Specific examples include polyethylene glycol and polypropylene group. Coal, polytetramethylene glycol, and monoalkyl ethers thereof, as well as copolymers of polyalkylene glycols represented by copolymers of polyethylene glycol and polypropylene glycol, and monoalkyl ethers thereof are also effective. Furthermore, polytrimethylene glycol and polyhexamethylene glycol, which are ring-opening polymers of oxetane and oxepane, and their monoalkyl ethers, and aliphatic polyester structures typified by polyε-caprolactone and polyδ-valerolactone. And a polymer having a terminal group of monool or diol. Furthermore, as the polyether, a polymer having [—O (CH ₂ ) n —OCH ₂ —] (where n = 2 or more) as a repeating unit is also effective. Examples include poly (dioxolane) diol, poly (dioxepane) diol, and the like. In addition, as long as the polymer has an active hydrogen, particularly a hydroxyl group at the end, in addition to the above, diene polymers such as polybutadiene and polyisoprene having a hydroxyl group at one or both ends, and hydrogenated diene polymers such as these It may be an elastomer. Further, bisphenol A or a polymer having a hydrogenated bisphenol A structure can be used as a copolymerization component in the polymer unit.

  Among these polymers (B-1), polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polycaprolactone diol, poly (dioxolane) diol, poly (dioxepane) diol, and monoalkyl ethers thereof are particularly preferable. Is a derivative. Furthermore, the average molecular weight of the polymer (B-1) is preferably 2000 or more in terms of number average. If the average molecular weight is less than 2000, the resulting polymer has a low molecular weight due to the chain transfer reaction that occurs during melt-kneading, and the desired polyacetal copolymer with excellent impact resistance can be obtained. Absent.

  Next, a specific example is shown about the polyacetal resin (A) of a non-quenching state, and the polymer (B-2) which performs melt kneading. The polymer (B-2) may be of any type as long as it has a glycidyl group in the molecule, but the basic skeleton of the polymer (B-2) is polyacetal copolymer as exemplified in the polymer (B-1). It is desirable that it can be a soft segment component that becomes an elastomeric element in the coalescence. Specific examples include polyethylene glycol, polypropylene glycol, glycidyl ethers of polyalkylene glycols typified by polytetramethylene glycol, copolymers of polyalkylene glycols typified by copolymers of polyethylene glycol and polypropylene glycol, etc. Of glycidyl ether. In addition, glycidyl ether of polytrimethylene glycol and polyhexamethylene glycol, which are ring-opening polymers of oxetane and oxepane, glycidyl ether of polymers having an aliphatic polyester structure typified by polyε-caprolactone, and long-chain alkyl groups For example, aliphatic glycidyl ether. Further, the polymer may contain a bisphenol A unit or a hydrogenated bisphenol A unit as an intramolecular copolymer component.

  Furthermore, as a polymer (B-3) that can be melt-kneaded with a non-quenched polyacetal resin (A) to form a polyacetal copolymer, an aliphatic polyether having a hydroxyl group in the molecule or a hydroxyl group in the molecule A polymer obtained by formalizing an aliphatic polyester having As the aliphatic polyether and aliphatic polyester used for the formalization, polyalkylene glycols listed in the section of the polymer (B-1), polyesters containing aliphatic alkyl units, and polyethers are preferable. This polymer (B-3) is a formal compound obtained by a dehydration reaction by heating a hydroxyl group in the polymer and formaldehyde or a formalin aqueous solution in the presence of an acidic catalyst. A monool having one hydroxyl group or a polyol having two or more hydroxyl groups in the molecule may be used. The polymer (B-3) may be a bimolecular reaction between polymers, a polymer obtained by a reaction between multiple molecules, a cyclic formal obtained by an intramolecular reaction, or a mixture thereof.

  Furthermore, the compound (B-4) that can be melt kneaded with the non-quenched polyacetal resin (A) to form a polyacetal copolymer is an alkyl monool having 6 or more carbon atoms or a carbon atom having 6 or more carbon atoms. It is a compound obtained by formalizing an alkylene diol. Examples of the diols used include aliphatic alkylene diols, and linear diols such as 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, and the like. , 2-hydroxyl substitution products and the like. As long as the alkylene chain has 6 or more carbon atoms, it may have a branched structure or a cyclic olefin unit.

  The formalized product used for the reaction by melt-kneading with the polyacetal resin (A) is basically preferably a cyclic product by an intramolecular formalization reaction, but may contain a formalized product by an intermolecular reaction.

  In producing a polyacetal copolymer by melt-kneading and reacting a non-quenched polyacetal resin (A) with a substance (B) selected from the above (B-1) to (B-4). Melt-kneading using a single-screw or twin-screw extruder is common, but the kneading method is not particularly limited to this. Melting and kneading is performed in the temperature range of 100 to 230 ° C., but considering the reaction between the non-quenched polyacetal resin in which the catalyst is in an active state and other polymers or compounds, the range of 150 to 210 ° C. is desirable .

  The amount of the substance (B) selected from (B-1) to (B-4) used for melt kneading is 1 to 50 parts by weight with respect to 100 parts by weight of the non-quenched polyacetal resin (A). Preferably there is. If the amount is less than 1 part by weight, it is difficult to obtain a polyacetal copolymer excellent in impact resistance which is the object of the present invention, and if it exceeds 50 parts by weight, the strength and rigidity are remarkably lowered.

  After the polyacetal resin (A) and the specific substance (B) are melt-kneaded and reacted to form a polyacetal copolymer as described above, the remaining polymerization catalyst is deactivated. The deactivation is performed by adding a basic compound or an aqueous solution thereof to the reaction product (polyacetal copolymer) obtained by melt-kneading, or by melt-kneading again with these.

  Basic compounds for neutralizing and deactivating the polymerization catalyst include ammonia, amines such as triethylamine, tributylamine, triethanolamine, and tributanolamine, or hydroxylation of alkali metals and alkaline earth metals. Salts and other known catalyst deactivators are used. In addition, stabilization treatment by a known method is performed as necessary, such as decomposition and removal of unstable ends by melting and kneading in the presence of a basic compound, or sealing of unstable ends with a stable substance.

  The stabilized polyacetal copolymer can be further blended with various necessary stabilizers, such as hindered phenol compounds, nitrogen-containing compounds, alkali or alkaline earth metal hydroxides, inorganic salts, Any one kind or two or more kinds of carboxylates can be mentioned. Further, as long as the present invention is not inhibited, general additives for thermoplastic resins, for example, coloring agents such as dyes and pigments, lubricants, nucleating agents, releasing agents, antistatic agents, surfactants, Alternatively, one or more organic polymer materials, inorganic or organic fibrous, powdery, and plate-like fillers can be added.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.
Examples 1-17 and Comparative Examples 1-7
As shown in Tables 1 to 3, various polymers or compounds were melted and kneaded into the non-quenched or quenched polyacetal resin (A) to prepare and evaluate polyacetal copolymers. The results are shown in Tables 1-3.

Preparation method of polyacetal resin (A) used, preparation method of polyacetal copolymer by melt kneading, substance (B) (polymer or compound of (B-1) to (B-4)) used for reaction by melt kneading The evaluation method of the obtained polyacetal copolymer is as follows.
[Preparation of polyacetal resin (A)]
1-1) Non-quenched polyacetal resin (A)
Trioxane, 1,3-dioxolane and methylal as a small amount of chain transfer agent are fed into a twin-screw extruder type continuous polymerization apparatus with a jacket temperature set at 80 ° C., and BF ₃ is supplied as a cationic polymerization catalyst. Polymerization was performed, and flaky polyacetal resin (A) was continuously collected from the outlet of the polymerization machine. The supply ratio of trioxane and 1,3-dioxolane used for the polymerization is 96: 4 mol%. The obtained flaky polyacetal resin (A) is melt-mixed with the substance (B) in order to suppress the deactivation of the catalyst with a basic compound and to suppress the progress of chain transfer and decomposition reaction. Until tempering, it was temporarily stored in a freezer at -35 ° C.
1-2) Quenched polyacetal resin (A-quench)
The polyacetal resin (A-quench) of the quench treatment used in Comparative Examples 1 to 3 was immersed in a 5% aqueous solution of triethylamine for 24 hours or more by immersing the polyacetal resin taken out in a flake form from the polymerization vessel outlet in the above polymerization. After deactivation of the catalyst, it was dehydrated and dried, and further melt-kneaded at 200 ° C. with a small amount (0.04% by weight) of an antioxidant (trade name “Irganox 1010”). Prepared.
[Preparation of polyacetal copolymer by melt kneading]
The melt-kneading of the non-quenched polyacetal resin (A) and the substance (B) selected from (B-1) to (B-4) is a biaxial extruder (manufactured by Nippon Steel Works; TEX-30). It was performed using. The cylinder temperature in melt kneading is 180 ° C. to 200 ° C. (die head part), the screw rotation is 120 rpm, and the feed amount is 6 kg / hr. The obtained polyacetal copolymer was pelletized and melted and kneaded again to 3% of a 5% aqueous solution of triethylamine and 0.2 parts by weight of a hindered phenol antioxidant (Irganox 1010; manufactured by Ciba Specialty Chemicals). In addition to the catalyst deactivation treatment, the stabilization treatment was performed.

In Comparative Examples 1 to 3, a melt-kneading similar to the above was performed using a quenched polyacetal resin (A-quench). However, no triethylamine aqueous solution was added during remelting and kneading.
[Substance (B) used for reaction by melt-kneading]
The polymer (B-1), polymer (B-2), polymer (B-3) and compound (B-4) used as the substance (B) in the examples are as follows.

The polymer (B ′) having no active hydrogen used in the comparative example is also shown.
(B-1)
B-1-1) Polyethylene glycol 20000 (Kishida Chemicals / Reagents)
B-1-2) Polypropylene glycol diol type 3000 (Wako Pure Chemicals and Reagents)
B-1-3) Polypropylene glycol monobutyl ether (Mn = 4000) (Aldrich product / reagent))
B-1-4) PEG-PPG-PEG (Block polymer; Mn = 5800) (Sigma Aldrich product / reagent)
B-1-5) Polycaprolactone (diol type) “Placcel H5” (manufactured by Daicel Chemical Industries)
B-1-6) Polytetramethylene glycol “PTG3000” (Hodogaya Chemical Co., Ltd.)
B-1-7) Poly (3-hydroxybutyric acid) diol (Sigma Aldrich product / reagent)
B-1-8) Polybutadiene “G3000” (manufactured by Nippon Soda), hydroxyl group product at both ends B-1-9) poly (dioxolane) diol (synthetic product)
The synthesis of poly (dioxolane) diol was performed as follows. 200 g of 1,3-dioxolane was poured into a 500 ml polymerization kettle and the internal temperature was set to 30 ° C. Polymerization was carried out using a solution obtained by diluting phosphorus / tungstic acid hydrate in methyl formate as a catalyst at a 150-fold concentration (weight ratio) in an amount of 20 ppm in terms of phosphorus / tungstic acid. When the viscosity in the system was sufficiently increased, 10 cc of a 2% dioxolane aqueous solution of triethylamine was added as a polymerization terminator. After stirring for an additional 15 minutes, the system was evacuated to remove unreacted monomer to obtain poly (dioxolane). Further, the obtained polymer was melt-kneaded with 5% aqueous triethylamine solution (added 3%) to remove unstable terminals, thereby obtaining a polymer having stable hydroxyl groups.
(B-2)
B-2-1) Polyethylene glycol diglycidyl ether, Mn = 526 (Sigma Aldrich product / reagent)
B-2-2) Polypropylene glycol diglycidyl ether, Mn = 640 (Aldrich product / reagent)
B-2-3) Epoxy / hydroxylated polybutadiene, Mn = 2600 (Aldrich product / reagent)
(B-3)
B-3-1) Polypropylene glycol formal (synthetic product)
Formalization was performed as follows. 40 g of polypropylene glycol 400 (manufactured by Sigma-Aldrich, reagent) and 20 ml of formalin aqueous solution were charged into a 200 ml eggplant flask, a small amount of benzene (about 10 ml) was added, and 0.2 ml of sulfuric acid was added as a catalyst. Set the flask temperature to 100 ° C and reflux for about 1 hour, then attach a distillation cooling tube, raise the temperature in the system to 110 ° C, and azeotrope the water produced by the reaction with benzene. Distilled out of the flask system. Benzene was added to the system as needed, and the reaction was continued until no water distills. After completion of the reaction, the system was neutralized with KOH, and acetone was added to precipitate the salt to remove it. Furthermore, acetone and a trace amount of water were removed by an evaporator. The obtained reaction product detected a peak in the vicinity of δ = 4.75 ppm in ¹ H-NMR. The formalization reaction was confirmed by the presence of this formal unit.
B-3-2) Formalized product of polypropylene glycol monobutyl ether (Aldrich product / reagent) (synthetic product; see B-3-1) for the synthesis procedure)
(B-4)
B-4-1) Formalization of 1,9-nonanediol (Tokyo Kasei Kogyo Co., Ltd./reagent) (synthetic product; see B-3-1) for synthesis procedure)
B-4-2) Formalization of 1,12-dodecanediol (Tokyo Kasei Kogyo Co., Ltd./Reagent) (synthetic product; see B-3-1) for synthesis procedure)
(B ′) Polymer B′-1 having no active hydrogen, polyethylene glycol dimethyl ether, Mn = 500 (Sigma Aldrich product / reagent)
B′-2) Polypropylene glycol diacrylate, Mn = 900 (Aldrich product / reagent)
B′-3) Polybutadiene “B3000” (manufactured by Nippon Soda), both terminal methyl type B′-4) polypropylene “Noblen W101” (manufactured by Sumitomo Chemical Co., Ltd.)
[Analysis and evaluation of polyacetal copolymer]
30 mg of the obtained polyacetal copolymer is once dissolved in hexafluoroisopropanol, and then the polymer or compound (B-1) to (B-4) or (B ′) used for melt-kneading (reaction) is soluble. The reaction was reprecipitated in a solvent, and the unreacted (B-1) to (B-4) or (B ′) was removed for analysis. The re-precipitated polyacetal copolymer was dissolved in 0.6 ml of polymer hexafluoroisopropanol d2 and analyzed by ¹ H-NMR, whereby (B-1) to (B-) into the polyacetal main chain were analyzed. 4) The amount of component introduced was calculated.

  Further, the obtained polyacetal copolymer was subjected to tensile test pieces and bending test pieces using a Toshiba IS80EPN molding machine in accordance with ISO standard conditions (9988-2) for evaluation of tensile strength / elongation and Charpy impact test. Were collected. The obtained test piece was allowed to stand for 48 hours under the conditions of a temperature of 23 ° C. and a humidity of 50%. The tensile test was measured according to ISO 527, and the Charpy impact test was measured according to ISO 179 using a notched bending test piece.

  Further, MFR measurement is based on ISO 1133, using a melt index device (manufactured by Takara Kogyo Co., Ltd.), using a piston with a load of 2160 g, staying at the temperature shown below for 7 minutes, and then being melt extruded by the piston load. The amount [g] of the resin composition was converted per 10 minutes for evaluation.

  The results are shown in Tables 1-3.

Claims (8)

The polyacetal resin (A) obtained by polymerization using a cationic polymerization catalyst is selected from the following (B-1) to (B-4) without deactivating the cationic growth terminal and polymerization catalyst. A method for producing a polyacetal copolymer, which is melt-kneaded with the material (B) to be produced.
B-1: Polymer having an active hydrogen atom in the molecule B-2: Polymer having a glycidyl group in the molecule B-3: An aliphatic polyether having a hydroxyl group in the molecule or an aliphatic polyester having a hydroxyl group in the molecule , A polymer obtained by formalization B-4: a compound obtained by formalizing an alkyl monool having 6 or more carbon atoms or an alkylene diol having 6 or more carbon atoms The method for producing a polyacetal copolymer according to claim 1, wherein the polymer (B-1) is a bifunctional polymer having active hydrogen atoms at both ends. The method for producing a polyacetal copolymer according to claim 1 or 2, wherein the active hydrogen atom of the polymer (B-1) is derived from a hydroxyl group. The method for producing a polyacetal copolymer according to any one of claims 1 to 3, wherein the polymer (B-1) has an aliphatic polyether skeleton or an aliphatic polyester skeleton. The polymer (B-1) is selected from polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polycaprolactone diol, poly (dioxolane) diol, poly (dioxepane) diol and monoalkyl ether derivatives thereof. The manufacturing method of the polyacetal copolymer of any one of 1-3. The method for producing a polyacetal copolymer according to claim 1, wherein the polymer (B-2) has an aliphatic polyether skeleton or an aliphatic polyester skeleton. Polyacetal resin (A) is a cationic polymerization catalyst comprising trioxane (a-1) and a cyclic ether compound (a-2) selected from ethylene oxide, 1,3-dioxolane, 1,4-butanediol formal and diethylene glycol formal. It is obtained by copolymerizing using, The manufacturing method of the polyacetal copolymer of any one of Claims 1-6. Either 1 to 50 parts by weight of a substance (B) selected from (B-1) to (B-4) is melt-kneaded with respect to 100 parts by weight of the polyacetal resin (A). A process for producing the polyacetal copolymer according to item 1.