JPS5853646B2 - Manufacturing method of polyacetal polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a polyacecool polymer having a desired molecular weight and excellent thermal stability, lubricity, antistatic properties, etc.

More specifically, anionic polymerization of formaldehyde is carried out using an alkylene oxide adduct to a long-chain alcohol or an ester compound of the same adduct as a molecular weight modifier to produce a polyacecool polymer with excellent thermal stability, lubricity, antistatic properties, etc. It's about how to get it.

Although it is stated in Japanese Patent Publication No. 35-9435 that the molecular weight of the formaldehyde polymer is determined from the amounts of trace amounts of water, methanol, and formic acid present in the polymerization system, U.S. Patent No. 3,017,389 also states that teeth,
There is a description that formaldehyde is polymerized in the presence of a chain transfer agent such as an alcohol, ester, acid anhydride, amide, or imide and an initiator.

Among the chain transfer agents found in these disclosures, compounds having so-called active hydrogen serve as good chain transfer agents, but have the disadvantage that the thermal stability of the resulting polymers is not necessarily good.

In addition, compounds such as esters, acid anhydrides, amides, imides, etc. have the disadvantage that their molecular weights cannot be adequately controlled, making it difficult to control their molecular weights.

As a result of extensive studies on methods for controlling the molecular weight of polyacecool polymers, the present inventors have found that alkylene oxide adducts to long-chain alcohols and ester compounds of the same adducts function as good molecular weight control agents, and that the resulting polymers thermal stability,
It was discovered that the lubrication properties, antistatic properties, etc. were also good, and the present invention was completed.

That is, the present invention relates to the general formula (R1: hydrogen, alkyl group, substituted alkyl group, allyl group, substituted allyl group, R2: C8 or higher alkyl group, substituted alkyl group, allyl group, substituted allyl group, R3: hydrogen, alkyl group) group, substituted alkyl group, allyl group, substituted allyl group, n
= 1 to 1,000) is characterized by anionic polymerization of formaldehyde in the coexistence of a compound selected from the group consisting of alkylene oxide adducts to long-chain alcohols represented by This invention relates to a method for producing a polyacetal polymer.

According to the method of the present invention, it is possible to easily produce a polyacetal polymer of any molecular weight that has excellent thermal stability, lubricity, antistatic properties, etc.

The present invention will be explained in detail below.

As the long chain alcohol, a higher alcohol having 8 or more carbon atoms and represented by the general formula R20H is used.

Here, R2 is selected from an alkyl group, a substituted alkyl group, an allyl group, and a substituted allyl group.

For example, octyl alcohol, decyl alcohol, lauryl alcohol, cetyl alcohol, stearyl alcohol, ceryl alcohol, myricyl alcohol, 2,6
．． 8-trimethyl-4-nonaol, 3-ethyl-6-
Examples include undecanol, p-butylphenol, p-octylphenol, p-nonylphenol, and p-1 tylbenzyl alcohol.

A compound represented by can be used.

Here, R1 is selected from hydrogen, an alkyl group, a substituted alkyl group, an allyl group, and a substituted allyl group.

Examples include ethylene oxide, propylene oxide, butylene oxide, epichlorohydrin, styrene oxide, p-chlorostyrene oxide, and the like.

Among these alkylene oxides, ethylene oxide and propylene oxide are particularly preferred.

These alkylene oxides can be used alone or in combination of two or more.

Alternatively, for example, propylene oxide can be first added to a long-chain alcohol, and then ethylene oxide can be further added thereto.

The number of moles (n) of alkylene oxide added per mole of long-chain alcohol must be in the range of 1 to 1,000, and the more preferable range is 2 to 250.b Alkylene to long-chain alcohol Although the oxide adduct can be used as it is in the present invention, the general formula R3C00H
It can also be esterified using a carboxylic acid or carboxylic acid anhydride represented by 1R3COCR3 and used as an ester compound.

Here, R3 is selected from hydrogen, an alkyl group, a substituted alkyl group, an allyl group, and a substituted allyl group.

Examples of carboxylic acids and carboxylic acid anhydrides include formic acid, acetic acid, propionic acid, caproic acid, 2-ethylhexanoic acid, lauric acid, stearic acid, acrylic acid, methyl methacrylic acid, benzoic acid, mandelic acid, and acetic anhydride. , propionic anhydride, caproic anhydride, benzoic anhydride, and the like.

Among these carboxylic acids and carboxylic acid anhydrides, acetic acid and acetic anhydride are particularly preferred.

It is desirable that alkylene oxide adducts to long-chain alcohols and ester compounds of the adducts be purified by methods such as distillation, adsorption, and drying prior to polymerization.

Further, these compounds can be used alone, or two or more kinds can be mixed and subjected to polymerization.

In the present invention, for formaldehyde polymerization, catalysts generally known as anionic polymerization catalysts and coordination anionic polymerization catalysts can be used.

Representative groups of these catalysts include Na-IJ
Alkali metals such as umum, potassium, alkali metal complex compounds such as sodium-naphthalene and potassium-anthracene, alkali metal hydrides such as sodium hydride, alkaline earth metal hydrides such as calcium hydride, sodium methoxide, potassium hydride, etc. Alkali metal alkoxides such as butoxide, alkali metal carboxylates such as sodium caproate and potassium stearate, alkaline earth metal salts of carboxylates such as magnesium caproate and calcium stearate, n-butylamine, diethylamine,
Amines such as trioctylamine and pyridine; quaternary ammonium salts such as ammonium stearate, tetrabutylammonium methoxide and dimethyl distearyl ammonium acetate; phosphonium salts such as tetramethylphosphonium propionate and trimethylbenzylphosphonium ethoxide; and tributyl. Examples include tetravalent organic tin compounds such as tin chloride, diethyltin dilaurate, and dibutyltin dimethoxide, and alkyl metals such as n-butyllithium and ethylmagnesium chloride.

Further, in the present invention, polymerization is usually carried out in an organic medium.

Examples of organic media that can be used in the present invention include aliphatic hydrocarbons such as n-hexane, n-heptane, and cyclohexane, aromatic hydrocarbons such as benzene, toluene, and xylene, and halogens such as methylene chloride, chloroform, and trichloroethylene. Examples include halogenated aliphatic hydrocarbons, halogenated aromatic hydrocarbons such as chlorobenzene, and ether compounds such as ethyl ether and tetrahydrofuran.

These organic media may be used alone or in combination of two or more.

The formaldehyde used in the present invention needs to be substantially anhydrous and needs to be purified using a known method such as a cold trap method or a solvent washing method.

Conventionally known methods such as blow polymerization and solution polymerization can be used to produce the polyacecooled polymer of the present invention.

The blow polymerization method is a method in which formaldehyde gas is directly blown into an organic medium containing a polymerization catalyst, an alkylene oxide adduct to a higher alcohol, and a molecular weight regulator selected from an ester compound of the adduct. The polymerization method is a method in which an organic medium containing a molecular weight regulator is cooled, formaldehyde gas is absorbed into this solution, and then a polymerization catalyst is added to initiate polymerization.

The molecular weight regulator is used after being uniformly dissolved or dispersed in an organic medium.

The concentration of the molecular weight modifier in the organic medium can be easily determined experimentally depending on the molecular weight requirements of the desired polyacecool polymer.

After the completed polymerization is separated from the organic medium,
The terminal unstable portion is blocked using, for example, acetic anhydride, and then a stabilizer and the like are added, and the product is put into practical use.

By using the production method of the present invention described in detail above, it has become possible to obtain a polyacecool polymer having both a desired molecular weight and excellent performance.

Here, the features of the present invention are listed as follows.

(1) It is possible to arbitrarily control the molecular weight of the polyacecool polymer.

(2) It is possible to control the molecular weight and at the same time impart excellent thermal stability, lubricating properties, antistatic properties, etc. to the polyacetal polymer.

The measurement items in the following examples are as follows: 0 Reduced viscosity: Polymer concentration 0.5 gr in P-chlorophenol-tetrachlorethylene (1:1 weight ratio) solution
, /dll at 60°C.

RV222: This is the amount of heat remaining when the polymer is heated at 222° C. for 10 minutes under vacuum, and is an index of the thermal stability of the polymer.

Friction coefficient: 2,2-methylene-bis(4-methyl-
6-tert-butylphenol) and 0.75 parts of a terpolymer of polycaprolactam/polyhexamethylene adipamide/polyhexamethylene sebamide were added, and after mixing using a 50 mmφ extruder, a thrust type Measured using a friction and wear tester, mating material: metal (S45C), load: 10kp/ffl, linear velocity: 12iec.The coefficient of friction is an index of lubricity.

Surface electrical resistance 2 The surface electrical resistance of the same polymer at 20°C,
Measured under 50% R, T, which is an index of antistatic property.

Example 1 Thoroughly dehydrated and dried paraformaldehyde was heated at 150°C.
The material is thermally decomposed by heating and passed through cooling cards several times.
Formaldehyde gas with a purity of 99.9% was obtained.

110 parts of formaldehyde gas per hour. O
X 10' mol/A of tetrabutylammonium acetate, 5, OX 10-3 as a molecular weight regulator
mo171 Cts H370 (CH2CH20) 40
H (ethylene oxide adduct to stearyl alcohol, average number of added moles of ethylene oxide 40, hereinafter 5-
40) in 500 parts of toluene.

At the same time as supplying formaldehyde gas, 1. OX10
-4 mol/l tetrabutylammonium acetate, 5. Toluene containing 5-40 OX 10-'' mol/g was continuously fed for 3 hours at a rate of 500 parts per hour.

Formaldehyde gas is also added at a rate of 110 parts per hour.
The polymerization temperature was maintained at 60°C during the continuous feeding for a period of time.

Toluene containing the polymer was continuously extracted in proportion to the amount supplied, and the polymer was separated by filtration.

After thoroughly washing the polymer with acetone, it was vacuum dried at 60°C.
89 parts of a white polymer was obtained.

The reduced viscosity of this polymer is 2.05, and Ru222 is 61%.
and has excellent thermal stability.

When this polymer was stabilized and then molded with the addition of a stabilizer, a very strong molded product could be obtained.

Furthermore, this molded article has a coefficient of friction of 0.16, a surface electrical resistance of 4×10''Ω, and has excellent lubricity and antistatic properties.

Examples 2 to 12 99.9% pure formaldehyde gas per hour
The mixture was continuously fed at a rate of 10 parts into 500 parts of cyclohexane containing the polymerization catalyst and molecular weight regulator shown in Table 1 for 3 hours.

Similarly to formaldehyde gas, cyclohexane containing the polymerization catalyst and molecular weight regulator shown in Table 1 was used continuously for 5 hours for 3 hours.
00@/'hr.

The polymerization temperature was maintained at the temperature shown in Table 1 during this period.

After separation of the polymer from cyclohexane, the same procedure as in Example 1 was carried out.

The obtained results are also shown in Table 1.

In all Examples, it was possible to obtain a polymer having a desired molecular weight and excellent thermal stability, lubricity, and antistatic properties.

Comparative Example 1 Among the reagents used in Example 1, all the reagents were the same as in Example 1, except that octatool was used as a molecular weight regulator instead of 5-40.
The results are shown in Table 1.

Although it is possible to control the molecular weight by using Octatool, the thermal stability, lubricity, and antistatic properties were poor.

Comparative Example 2 All of the reagents used in Example 1 were operated in the same manner as in Example 1, except that octyl propionate was used as a molecular weight regulator in place of 5-40, and the results are shown in Table 1. Ta.

In the case of n-octylpropionate, the molecular weight control of the polymer was incomplete, and at the same time, the thermal stability, lubricity, and antistatic properties were also poor.

Claims (1)

[Claims] 1 General formula (R1: hydrogen, alkyl group, substituted alkyl group, allyl group, substituted allyl group, R2 = alkyl group having 8 or more carbon atoms, substituted alkyl group, allyl group, substituted allyl group, R3 :hydrogen,
A compound selected from the group consisting of an alkylene oxide adduct to a long-chain alcohol represented by an alkyl group, a substituted alkyl group, an allyl group, a substituted allyl group, n=1 to 1,000) and an ester compound of the same adduct. A method for producing a polyacetal polymer characterized by anionic polymerization of formaldehyde in the coexistence of formaldehyde. 2. The production method according to claim 1, wherein the alkylene oxide is ethylene oxide or propylene oxide. 3. The production method according to claim 1 or 2, wherein the number of moles (n) of added alkylene oxide per mole of long-chain alcohol is in the range of 2 to 250. 4. The manufacturing method according to claim 1, wherein the ester compound is an acetate ester.