JPS5915333B2 - Polyacetal copolymer and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel polyacetal copolymer, and more particularly to a polyacetal copolymer having a novel terminal structure that has unprecedented lubricity and antistatic properties, and a method for producing the same. be.

Acetal copolymers are usually obtained by copolymerizing formaldehyde, trioxane, and a cyclic ether using a cationic polymerization catalyst such as boron trifluoride or tin tetrachloride.

The copolymer thus obtained has unstable portions consisting of repeating oxymethylene units ({H2O-) at both ends of the polymer. The acetal copolymer is put into practical use after the terminals of the copolymer are made into a stable structure by hydrolyzing the unstable portions in the presence of a basic substance. Japanese Patent Publication No. 41-21638 discloses adding methylal, acetal, formic acid, etc. as a chain transfer agent during the copolymerization reaction of trioxane.

Furthermore, JP-A No. 48-29843 describes copolymerizing trioxane in the presence of polyether. As a result of extensive studies on molecular weight regulators, the present inventors have discovered that a certain specific compound functions not only as a good molecular weight regulator but also as an end-capping agent.

As a result, we have discovered a new polyacetal copolymer that has extremely excellent lubricity and antistatic properties not found in conventional acetal copolymers. That is, the present invention provides oxyalkylene units (4) MO+ (RO: hydrogen, alkyl group, substituted alkyl group,
They are selected from aryl groups and substituted aryl groups, and may be the same or different.

A linear polymer having a structure in which m = 2 to 6) is inserted,
At least one terminal is selected from the general formula (R1: hydrogen, an alkyl group, a substituted alkyl group, an aryl group, and a substituted aryl group, and each may be the same or different.

R2: alkyl group-substituted alkyl group, aryl group, substituted aryl group, R3: hydrogen, alkyl group, substituted alkyl group,
Aryl group, substituted aryl group, m=2-6, n=1-1
. It is about merging. The high molecular weight polyacetal copolymer of the present invention has a friction coefficient of 0.14 to 0.30 and a surface electrical resistance of 1 x 1011 to 1 x 1016, and has unprecedented lubricity and antistatic properties. It is a stable copolymer. Such excellent performance is based on the terminal structure of the polyacetal copolymer, and at the same time, the terminal structure of the polyacetal copolymer is based on a molecular weight regulator having an extremely good molecular weight regulating function. Therefore, it goes without saying that the polyacetal copolymer of the present invention has a desired molecular weight. Demand for polyacetal as an engineering resin has been increasing in recent years, and improvements in the lubricating properties and antistatic properties of polyacetal copolymers have great industrial significance.

Next, the polyacetal copolymer of the present invention will be specifically explained.

The polyacetal copolymer referred to in the present invention is a linear polymer having a structure in which oxyalkylene units are inserted into a polymer mainly consisting of repeating oxymethylene units, and at least one terminal of the polymer is , is a polymer blocked with .

The content of oxyalkylene units in the polyacetal copolymer is 0.0% per 100 moles of oxymethylene units.
05 to 50 mol, more preferably 0.1 to 20 mol.

The structural formula of the polyacetal copolymer of the present invention is as follows.

(R4, R,, R6: hydrogen, alkyl group, substituted alkyl group, aryl group, substituted aryl group indicates that the oxyalkylene unit of b is randomly inserted into the oxymethylene 1ν0 lene unit of a) .

) Of the structural formulas exemplified above, the polyacetal copolymers represented by (1) (when R4 is hydrogen) and (4) have a hydroxyl group at the end.

The hydroxyl group at the end of the copolymer is unstable and must be converted into a stable group using known methods such as esterification, etherification, or urethanization, or the terminal unformed group may be converted into a stable group in the presence of a basic substance. The stable portion is removed by hydrolysis.
Furthermore, among the structural formulas exemplified above, the polyacetal copolymers represented by (1) (when R4 is other than hydrogen), (2), (3), and (5) are stable because both ends are blocked. Yes, it can be put into practical use as is.

The structure of the polyacetal copolymer of the present invention is confirmed by the following method.

That is, when a polyacetal copolymer is hydrolyzed in an acidic aqueous solution, the portion consisting of repeating oxymethylene units becomes formaldehyde, and the portion of oxyalkylene units inserted into the main chain becomes alkylene glycol HO.
It becomes l(ku)MOIH. Also, the terminal R2Ol(仝)MO
l-.

The group becomes R2Ol(÷)MOlnH, and the terminal R3C
Ol((:.)MO-1-Todoroki R3COOH and HO
It becomes i (÷) MO Dou voice.

These compounds are analyzed and quantified by means such as gas chromatography and liquid chromatography. The number average molecular weight of the polyacetal copolymer of the present invention excluding the terminal groups is the same as that of ordinary high molecular weight polyacetals, and is preferably between 0,000 and 500,000.

The lower limit of the number average molecular weight is limited by the physical properties of the polyacetal copolymer, and the upper limit is limited by the moldability of the polyacetal copolymer. The number average molecular weight of the polyacetal copolymer is determined by the following method. That is, the number average molecular weight is 1
If the number average molecular weight is 100,000 or less, use the osmotic pressure method or end group determination method, and if the number average molecular weight is 100,000 or more, use the weight average molecular weight determined by the light scattering method and gel permeation chromatography. The number average molecular weight is determined by combining the elution curve determined by the graph method (G.P.C. method). In the polyacetal copolymer of the present invention, the oxyalkylene unit to be inserted into the polymer mainly consisting of repeating oxymethylene units has the general formula
RO: selected from hydrogen, an alkyl group, a substituted ↓ to υ alkyl group, an aryl group, and a substituted aryl group, and each may be the same or different.

m=2 to 6). For example, oxyethylene unit + (CH2) 20L oxypropylene unit 4CH2 (1
1/HO+, oxytrimethylene unit -Fc. (CH2
) 30'+-, oxytetramethylene unit + γM''state:;:g? paleo? phenylethylene unit ↓ CH, and HO ↓
There is.

Among these oxyalkylene units, oxyethylene units and oxytetramethylene units are particularly preferred from the viewpoint of improving the physical properties of the polyacetal copolymer.
The alkylene oxide adduct to alcohol and the alkylene oxide adduct to carboxylic acid, which form the terminal end of the polyacetal copolymer of the present invention, have the general formula -! breath
v It is a compound having the structure represented by Todoro▼nase, and has the general formula R2OH (R2: alkyl group,
alcohol represented by a substituted alkyl group, aryl group, substituted aryl group), or alcohol represented by the general formula R3COOH (R3
: hydrogen, alkyl group, substituted alkyl group, aryl group, substituted aryl group), to a carboxylic acid represented by the general formula (R
1: hydrogen, alkyl group, substituted alkyl group, aryl group,
They are selected from substituted aryl groups and may be the same or different.

It is a compound to which an alkylene oxide represented by m=2 to 6) is added. Examples of the alcohol include methyl alcohol, ethyl alcohol, Sec-butyl alcohol, hexyl alcohol, cyclohexyl alcohol, octyl alcohol, decyl alcohol, lauryl alcohol, cetyl alcohol, stearyl alcohol, eicosanol, ceryl alcohol, myricyl alcohol, oleyl alcohol, Examples include 3-ethyl-6-undecanol, phenol, p-butylphenol, p-octylphenol, p-nonylphenol, benzyl alcohol, p-butylbenzyl alcohol, and the like.

Among these alcohols, from the viewpoint of improving the lubricating performance of the polyacetal copolymer, long-chain aliphatic alcohols having 8 or more carbon atoms and p-alkyl-substituted phenols are preferable, and from the viewpoint of easy availability, lauryl alcohol and stearyl alcohol are preferable. Particularly preferred are alcohols, eicosanol, p-octylphenol and p-nonylphenol. Examples of carboxylic acids include acetic acid, propionic acid, caproic acid, 2-ethylhexanoic acid, lauric acid, palmitic acid, stearic acid, behenic acid, oleic acid,
Examples include linoleic acid, ricinoleic acid, phenyl acetic acid, cinnamic acid, benzoic acid, p-octylbenzoic acid, and α-naphthalic acid.

Among these carboxylic acids, from the viewpoint of improving the lubrication performance of the polyacetal copolymer, long-chain aliphatic carboxylic acids having 8 or more carbon atoms are preferred, and from the viewpoint of easy availability, lauric acid, stearic acid, and oleic acid are preferred. Particularly preferred are acids and ricinoleic acid. Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, epichlorohydrin, styrene oxide, oxetane, 3,3-bis(chloromethyl)oxetane, tetrahydrofuran, 2-methyltetrahydrofuran, oxepane, and the like.

Among these alkylene oxides, ethylene oxide is particularly preferred from the viewpoint of antistatic performance, and ethylene oxide and propylene oxide are particularly preferred from the viewpoint of easy availability. These alkylene oxides can be used alone or in combination of two or more.

Alternatively, for example, propylene oxide can be added to the alcohol or carboxylic acid first, then ethylene oxide can be added thereto, and then propylene oxide can be added thereto. The number of moles (n) of alkylene oxide added per mole of alcohol or carboxylic acid must be in the range of 1 to 1,000.

In order to improve the lubricating performance and antistatic performance of the polyacetal copolymer, it is preferable that n be large, while from the viewpoint of ease of production and purification, it is preferable that n be small. Based on both of these constraints, the most preferable range of n is 2 to
It is between 250. Next, a method for producing the polyacetal copolymer of the present invention will be described.

The polyacetal copolymer of the present invention has a general formula (R1: selected from hydrogen, an alkyl group, a substituted alkyl group, an aryl group, and a substituted aryl group, each of which may be the same or different.

R2: alkyl group, substituted alkyl group, aryl group, substituted aryl group, R3: hydrogen, alkyl group, substituted alkyl group, aryl group, substituted aryl group, R4: hydrogen, alkyl group, substituted alkyl group, aryl group, substituted aryl group, R
5: hydrogen, alkyl group, substituted alkyl group, aryl group,
Substituted aryl group, R6: hydrogen, alkyl group, substituted alkyl group, aryl group, substituted aryl group, m=2-6, n=
In the presence of a compound selected from the group consisting of alkylene oxide adducts to alcohols and alkylene oxide adducts to carboxylic acids, represented by Obtained by copolymerizing with ether.

The first group of alkylene oxide adducts to alcohols include compounds represented by the general formula D Ha1 (R4: hydrogen, alkyl group, substituted alkyl group, aryl group, substituted aryl group).

For example, ethylene glycol monostearyl ether,
Examples include ethylene glycol dioleyl ether, polyethylene glycol dibutyl ether, and polypropylene glycol monostearyl ether. The second group includes compounds represented by the general formula (R5: hydrogen, alkyl group, substituted alkyl group, aryl group, substituted aryl group).

Examples include diethylene glycol monostearyl ether monoacetate, polyethylene glycol monooleyl ether monopropionate, polybutylene glycol monostearyl ether monocaproate, and the like. Next, the first group of alkylene oxide adducts to carboxylic acids includes compounds represented by the general formula.

Examples include tetraethylene glycol monolaurate, polyethylene glycol monostearate, polytetramethylene glycol monooleate, and the like. The second group includes compounds represented by the general formula (R6: hydrogen, alkyl group, substituted alkyl group, aryl group, substituted aryl group).

Examples include triethylene glycol dicaproate, polyethylene glycol dilaurate, polypropylene glycol distearate, and the like. It is desirable that alkylene oxide adducts to alcohols and carboxylic acids be purified by methods such as distillation, adsorption, and drying before being used in polymerization as molecular weight modifiers.

Further, these compounds can be used alone, or two or more kinds can be mixed and subjected to polymerization. In the present invention, sufficiently purified trioxane, formaldehyde, and polyoxymethylene can be used as starting materials for synthesizing a polyacetal copolymer.

The first group of cyclic ethers to be copolymerized with these starting materials is selected from the general formula (RO: hydrogen, alkyl group, substituted alkyl group, aryl group, substituted aryl group, even if they are the same). It's okay to be different.

There are alkylene oxides represented by m=2 to 6).
Examples include ethylene oxide, propylene oxide, butylene oxide, epichlorohydrin, styrene oxide, oxetane, 3,3-bis(chloromethinooxetane, tetrahydrofuran, oxepane, etc.). Among these alkylene oxides, ethylene oxide is particularly preferred. As a group, there is a cyclic form expressed generally.

Examples include ethylene glycol formal, propylene glycol formal, diethylene glycol formal, triethylene glycol formal, 1,4-butanediol formal, 1,5-pentanediol formal, and 1,6-hexanediol formal. Among these cyclic formals, ethylene glycol formal, diethylene glycol formal and 1,
4-butanediol formal is preferred. Cyclic ether is 0.03 to 100 parts by weight per 100 parts by weight of starting materials.
It is used in an amount of 0.1 to 50 parts by weight, preferably 0.1 to 50 parts by weight.

In the present invention, a catalyst known as a cationic polymerization catalyst can be used for the copolymerization of the starting material and the cyclic ether.

For example, tin tetrachloride, tin tetrabromide, titanium tetrachloride, aluminum trichloride, zinc chloride, vanadium trichloride, antimony pentafluoride, boron trifluoride, boron trifluoride diethyl etherate, boron trifluoride acetate So-called Friedel-Crafts type compounds such as anhydrate, boron trifluoride coordination compounds such as boron trifluoride triethylamine complex compounds,
perchloric acid, acetyl perchlorate, hydroxyacetic acid,
Trichloroacetic acid. Inorganic and organic acids such as p-toluenesulfonic acid, triethyloxonium tetrafluoroborate, triphenylmethylhexafluoroantimonate,
Complex salt compounds such as allyldiazonium hexafluorophosphate, allyldiazonium tetrafluoroborate,
Examples include alkyl metals such as diethylzinc, triethylaluminum, and diethylaluminum chloride.
The cationic polymerization catalyst was used in an amount of 0.0% per 100 parts by weight of starting materials.
It is used in a range of 0005 to 5 parts by weight.

The copolymerization of the starting material and the cyclic ether is carried out without a solvent or in an organic medium. For copolymerization without a solvent, a cationic polymerization catalyst is added to a mixture of the starting materials in a solid, molten or gaseous state, a cyclic ether and alcohol, and a molecular weight modifier selected from alkylene oxide adducts to carboxylic acids. It is done as follows. Copolymerization in an organic medium is carried out by adding a cationic polymerization catalyst to the organic medium containing the starting materials, cyclic ether, and molecular weight regulator. Organic media that can be used in the present invention include aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, n-octane, cyclohexane, and cyclopentane, and aromatic hydrocarbons such as benzene, toluene, and xylene. , halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, ethylene chloride, and trichloroethylene, and halogenated aromatic hydrocarbons such as chlorobenzene and o-dichlorobenzene.

These organic media may be used alone or in combination of two or more. The molecular weight regulator is used after being uniformly dissolved or dispersed in the reaction system.

The concentration of the molecular weight regulator in the system can be easily determined by experiment, depending on the molecular weight requirements of the desired polyacetal copolymer. The reaction temperature is usually -20~
It is set between 23'C, but in the case of no solvent, it is set between 20 and
It is more preferably between 210°C, and more preferably between 10 and 120°C when an organic medium is used.

There is no particular restriction on the reaction time, but it is set between 5 seconds and 300 minutes.

After a predetermined period of time has elapsed, a basic substance is added to the reaction system to complete the copolymerization.

The obtained copolymer is stabilized by removing unstable ends by hydrolysis or blocking unstable ends by a method such as esterification. The stabilized polyacetal copolymer is put into practical use with the addition of stabilizers and the like. The features of the polyacetal copolymer of the present invention and its production method which have been described in detail above are listed below. (1) The polyacetal copolymer has extremely excellent lubricity and antistatic properties.

(2) By using a specific compound, excellent performance can be imparted to a polyacetal copolymer, and at the same time, the molecular weight of the copolymer can be arbitrarily controlled.

Measurement items in the following examples are as follows. Reduced viscosity: Polymer concentration 0.5 gr/D in p-chlorophenol-tetrachlorethylene (1:1 weight ratio) solution
Measured value at 60℃ at Z.

R222: This is the amount remaining after heating a polymer that has been terminally stabilized using acetic anhydride at 222°C for 60 minutes under vacuum, and is an index of the thermal stability of the polymer.

Friction coefficient: 2,2-methylene-bis(4-methyl-
0.25 parts of 6-Tert-butylphenol) and 0.75 parts of a terpolymer of polycaprolactam/polyhexamethylene adibamide/polyhexamethylene sebaamide were added, mixed and molded using a 50 mmφ extruder, Measured using a thrust type friction and wear tester, mating material: metal (S
45°C) Load: 10Kf/Go line speed: 12? /Length C The coefficient of friction is an index of lubricity.

Surface electrical resistance: The surface electrical resistance of the same polymer at 20℃,
50%R. H. Measured below, it is an indicator of antistatic properties.

Example 1 and Production Example 1 (1) Production of polyacetal copolymer 500 parts of sufficiently purified trioxane (hereinafter "parts" indicate parts by weight) was placed in a secondary cylinder having two Σ-type stirring blades.

), 15 parts of ethylene oxide, Cl8H37O (CH2
28.5 parts of CH2O)40C18H37 (polyethylene glycol distearyl ether, average number of added moles of ethylene oxide: 40, hereinafter abbreviated as DS-40) was charged and heated to 70°C. Next, 0.3 part of boron trifluoride dibutyl etherate was added to this secondary solution and stirred for 70 minutes. Immediately thereafter, 10 parts of tributylamine was added to stop the copolymerization. The contents were taken out from the kneader and washed with acetone to obtain 507 parts of polyacetal copolymer. (2) Confirmation of the structure of polyacetal copolymer (1)
5 parts of the polyacetal copolymer obtained above were dispersed in 95 parts of a 1N aqueous hydrochloric acid solution and heated at 90°C for 6 hours.

Through this hydrolysis operation, the portion consisting of oxymethylene units was converted to formaldehyde, and the portion consisting of oxyethylene units was converted to ethylene glycol. Analysis by gas chromatography revealed that 20 moles of oxyethylene units were inserted per 100 moles of oxymethylene units in this copolymer. Then,
This solution was neutralized with a 0.5N aqueous sodium hydroxide solution, and the liquid was evaporated at normal pressure, followed by addition of 50 parts of tetrahydrofuran for extraction. When the extract was quantified using liquid chromatography, the following substances were detected at the following concentrations per 1 mole of formaldehyde. Cl8H
37O(CH2CH2O)40H7.3×1I4molC
50 parts of a copolymer obtained with 7.3 x 14 moles (1) of 18H37OH was heated at 139°C for 3 hours with 500 parts of acetic anhydride and 0.1 part of sodium acetate to carry out terminal acetylation.
49 parts of polymer were recovered.

Then, when the terminal acetyl groups of this polymer were analyzed using infrared absorption spectroscopy, 4.times.10@-5 mol of terminal acetyl groups were detected per 1 mol of formaldehyde. This terminal acetyl group corresponds to the terminal hydroxyl group of the copolymer obtained in (1). From the above analysis, the total terminal groups of the copolymer obtained in (1) are 15.0 x 10-4 mol/1 mol of formaldehyde, and the number average molecular weight is Mn = 60/total terminal groups. , 40,000.

The structure and composition of the copolymer obtained in (1) are as follows. (A) Cl8H37O(CH2CH2O)4
0 {(CH2O)12,, (CH2CH2O)26}C
l8H3, 97% by weight (B) HO{(CH2O)12
,5(CH2CH2O)26}H3% by weight (structural formula {(
CH2O)1,,5(CH2CH2O) turtle} is 129
This indicates that 26 oxyethylene units are inserted into the oxymethylene units of 5, and does not specify the distribution of oxyethylene units in the polymer chain.

) Among the above two types of copolymers, (A) is a copolymer based on DS-40 added as a molecular weight regulator, and (B)
is a water-based copolymer that was present in trace amounts in the polymerization system. 3) Measurement of physical properties of polyacetal copolymer The reduced viscosity of the polyacetal copolymer obtained in (1) is 1.
85, which was the desired value.

Furthermore, Rv was 99%, indicating excellent thermal stability. When a stabilizer was then added to a polymer that had been terminally stabilized using acetic anhydride and molded, a very strong molded product could be obtained. Also, the friction coefficient of this molded product is 0.16,
The surface electrical resistance was 4×10 11 Ω, and the lubrication performance and antistatic performance were excellent. Spoon Example 2 and Production Example 2 4) Production of polyacetal copolymer Formaldehyde gas with a purity of 99.901) was added at a rate of 100 parts per hour to 1.7 x 104 as a comonomer.
mol/l propylene oxide, 3 as molecular weight regulator
．． 2×10−3 mol/l n-CJI,O(CH2CH
ρ) 20×QlH23 (a compound obtained by esterifying the ethylene oxide adduct of n-butyl alcohol with lauric acid, average number of added moles of ethylene oxide 20, hereinafter B
L-20), 1 x 10-3 mol/as a polymerization catalyst
The mixture was continuously fed into 500 parts of toluene containing 1 tin tetrachloride for 3 hours.

Toluene containing a comonomer, a molecular weight regulator, and a polymerization catalyst at the above concentrations was also continuously fed at a rate of 500 parts/Hr for 3 hours, and the polymerization temperature was maintained at 5° C. during this period. The copolymer was separated from toluene, washed and dried to obtain 273 parts of a polymer. 5) Confirmation of structure of polyacetal copolymer The following results were obtained by hydrolyzing the polyacetal copolymer obtained in (4).

Oxypropylene unit insertion rate 28 mol/100 mol oxymethylene unit n-{4H,
0(CH2CH2O)20H4.5×10-4 mol/1
Molar formaldehyde CllH23COOH4.5×1
0→mol/1 mol formaldehyde Furthermore, by acetylating the polymer obtained in (4), the number of terminal carbonyl groups increased by 5×10 5 mol/1 mol formaldehyde.

The increased terminal carbonyl groups correspond to the terminal hydroxyl groups of the copolymer obtained in (4). From the above analytical values, the polymer obtained in (4) has a number average molecular weight of 63.
200, and is a mixture of the following two types of copolymers.

This shows that 57 oxypropylene units are inserted into 2020 oxymethylene units.

) Among the above two types of copolymers, (C) is a copolymer based on BL-20 added as a molecular weight regulator, and (D)
is a copolymer based on water present in trace amounts in the polymerization system.

(6) Measurement of physical properties of polyacetal copolymer The measured physical properties of the polyacetal copolymer obtained in (4) are as follows.

Reduced viscosity 3.50, R99 (/f), friction coefficient 0.19
, surface electrical resistance 5×1015Ω.

This copolymer has excellent lubrication performance, and the good lubrication performance is based on the copolymer represented by the structural formula (0).

Example 3 and Production Example 3 (7) Production of polyacetal copolymer 150 parts of dehydrated and dried polyoxymethylene dihydroxide with a number average molecular weight of 1.5 x 105, 3.5 parts of ethylene oxide, 5 x Cl7H35XO (CH2CH2O)
Cl7H35 (a compound obtained by esterifying an ethylene oxide adduct to stearic acid with stearic acid, average number of added moles of ethylene oxide 5, hereinafter abbreviated as DS-5)
7 parts autoclave containing 3.1 parts and 500 parts toluene.
Heated to 5°C.

Next, 0.1 part of boron trifluoride diethyl etherate was added to the autoclave and stirred for 40 minutes. After adding 2 parts of tributylamine to the autoclave, the contents were taken out, washed and dried to recover 151 parts of polymer. (8) Confirmation of structure of polyacetal copolymer When the structure of the polymer obtained in (7) was analyzed using the same method as in Example 1, it was confirmed that the following two types of copolymers were formed. .

(Structural formula {(CH2O)980(CH2CH2O)15
} indicates that 15 oxyethylene units are inserted into 980 oxymethylene units.

) Among the above two types of copolymers, (E) is a polymer based on DS-5 added as a molecular weight regulator, and (F) is a polymer based on DS-5 added as a molecular weight regulator.
It is a copolymer based on the terminal hydroxyl group of the starting material polyoxymethylene and a small amount of water present in the polymerization system.

(9) Measurement of physical properties of polyacetal copolymer The measured physical properties of the polyacetal copolymer obtained in (7) are as follows.

Reduced viscosity 1.56, R99%, friction coefficient 0.24, Table-
The lubrication performance of the copolymer obtained with a sheet electrical resistance of 6×10 14 Ω (7) is improved by the copolymer represented by (E).

Comparative Example 1 and Comparative Production Example 1 (8) Production of acetal copolymer All of the equipment and reagents used in Production Example 1 were the same as in Example 1, except that 0.010 parts of water was added instead of DS4O. In the same manner as above, 495 parts of acetal copolymer was obtained.

al). When the copolymer obtained in the process of confirming the structure of the acetal copolymer was hydrolyzed and analyzed, 20 moles of ethylene glycol was detected per 100 moles of formaldehyde.

The copolymer obtained in (10) was acetylated and the terminal acetyl group was quantified to obtain a value of 20.0 x 10-4 mol/1 mol formaldehyde. From the above analysis values, the copolymer (10) is HO{(CH2O),,o(CH2O)19}H
It has a structure of 100% by weight.

({(CH,O),,,(CH,O)1,} is 970
This shows that 19 oxyethylene units are inserted into the oxymethylene units of .

) α2) Measurement of physical properties of acetal copolymer The measured physical properties of the copolymer obtained in (10) are as follows.

Reduced viscosity 1.62, R98Ol), friction coefficient 0.37,
The copolymer obtained with a surface electrical resistance of 1016 Ω (10) had poor lubricating performance and antistatic performance.

Examples 4 to 10 Table 1 summarizes examples of the present invention.

In all Examples, it is clear that the polyacetal copolymer has excellent lubricity and antistatic properties.
Comparative Examples 2-3 Comparative examples are also shown in Table 1.

Claims (1)

[Claims] 1 Oxymethylene unit ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Oxyalkylene units in the range of 0.05 to 50 moles in 100 moles ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ (R
_0: selected from hydrogen, an alkyl group, a substituted alkyl group, an aryl group, and a substituted aryl group, each of which may be the same or different. At least one end of a linear polymer having a structure in which m = 2 to 6) is randomly inserted has a general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (R_1: hydrogen, alkyl group, substituted alkyl group, Selected from aryl groups and substituted aryl groups, each of which may be the same or different. R_2: alkyl group, substituted alkyl group, aryl group, substituted aryl group, R_3: hydrogen, alkyl group, substituted alkyl group, aryl group , substituted aryl group, m=2-6, n=
1 to 1,000) with a number average molecular weight excluding terminal groups of 10,000, capped with a compound selected from the group consisting of alkylene oxide adducts to alcohols and alkylene oxide adducts to carboxylic acids represented by From 500,0
Polyacetal copolymer between 00 and 00. 2 Oxyalkylene unit is oxyethylene unit ▲ mathematical formula, chemical formula,
The copolymer according to claim 1 which is ▼. 3. The copolymer according to claim 1, wherein the oxyalkylene unit is an oxytetramethylene unit (numerical formula, chemical formula, table, etc.). 4. The copolymer according to claim 1, wherein the alcohol is a long-chain aliphatic alcohol having 8 or more carbon atoms. 5. The copolymer according to claim 4, wherein the alcohol is lauryl alcohol, stearyl alcohol, or eicosanol. 6. The copolymer according to claim 1, wherein the alcohol is a p-alkyl substituted phenol. 7. The copolymer according to claim 6, wherein the alcohol is p-octylphenol or p-nonylphenol. 8. The copolymer according to claim 1, wherein the carboxylic acid is a long-chain aliphatic carboxylic acid having 8 or more carbon atoms. 9. The copolymer according to claim 8, wherein the carboxylic acid is lauric acid, stearic acid, oleic acid, or ricinoleic acid. 10. The copolymer according to claim 1, wherein the alkylene oxide is ethylene oxide. 11. The copolymer according to claim 1, wherein the alkylene oxide is propylene oxide. 12. The copolymer according to any one of claims 1 to 11, wherein the number (n) of added moles of alkylene oxide per mole of alcohol or carboxylic acid is in the range of 2 to 250. 13 General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Or ▲ There are mathematical formulas, chemical formulas, tables, etc. R_2: Alkyl group, substituted alkyl group, aryl group, substituted aryl group, R_3: Hydrogen, alkyl group, substituted alkyl group, aryl group, substituted aryl group, R_4: Hydrogen, alkyl group, substituted Alkyl group, aryl group, substituted aryl group, R_5: hydrogen, alkyl group, substituted alkyl group, aryl group, substituted aryl group, R_6: hydrogen, alkyl group,
Substituted alkyl group, aryl group, substituted aryl group, m=2
~6, n=1-1,000) In the presence of a compound selected from the group consisting of alkylene oxide adducts to alcohols and alkylene oxide adducts to carboxylic acids, represented by A method for producing a polyacetal copolymer, which comprises copolymerizing a compound selected from the group consisting of polyoxymethylene and a cyclic ether. 14. The production method according to claim 13, wherein the cyclic ether is ethylene oxide. 15 Cyclic ether is ethylene glycol formal,
14. The manufacturing method according to claim 13, wherein diethylene glycol formal or 1,4-butanediol formal is used. 16 Claim 13 in which the copolymerization is carried out without a solvent
Manufacturing method described in section. 17. The method according to claim 13, wherein the copolymerization is carried out in an organic medium.