JPH0333172B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel block copolymer, and more particularly to a novel block copolymer having unprecedentedly excellent lubrication and antistatic properties, and a method for producing the same. Polyacetal is usually obtained by homopolymerizing formaldehyde or copolymerizing formaldehyde, trioxane, and a cyclic ether. Japanese Patent Publication No. 35-9435 states that the molecular weight of a formaldehyde polymer is determined by the amounts of trace amounts of water, methanol, and formic acid present in the polymerization system. Further, US Pat. No. 3,017,389 describes that formaldehyde is polymerized in the coexistence of a chain transfer agent such as an alcohol, ester, acid anhydride, amide, or imide. In Japanese Patent Publication No. 41-21638, methylal, acetal,
It is disclosed that formic acid or the like is added as a chain transfer agent. In addition, in Japanese Patent Application Laid-Open No. 48-29843,
Copolymerization of trioxane in the presence of polyether is described. Furthermore, Japanese Patent Publication No. 56-42611 discloses that the terminal hydroxy group of a formaldehyde polymer is reacted with triorganohydroxysilane to stabilize the polymer. Furthermore, Japanese Patent Publication No. 35-2194 discloses that formaldehyde is polymerized in the presence of a polymer such as polytetramethylene glycol. No matter which method is used, it is not possible to simultaneously improve the lubricating performance and antistatic performance of polyacetal. The present inventors have extensively studied molecular weight regulators to be used during polymerization, and have found that a certain specific polymer functions as a good molecular weight regulator. As a result, we have discovered a new block copolymer that has both extremely excellent lubrication and antistatic properties that have not been seen in conventional polyacetals. Furthermore, this block copolymer is endowed with the high strength and rigidity that are characteristic of polyacetal. Therefore, the block copolymers of the present invention can be appropriately called polyacetals with high performance. That is, the present invention comprises an acetal polymer unit (A) and a general formula (B) (R ₁ : Selected from hydrogen, alkyl group, and phenyl group, each of which may be the same or different. R ₂ : Selected from hydrogen, an alkyl group, and phenyl group, each of which may be the same or different. X: oxygen, methylene group a: 1-1000 b: 1-1000 n: 2-6) -A triblock copolymer, wherein the acetal polymer unit (A)
is an acetal homopolymer consisting of repeating oxymethylene units (CH ₂ O-) or a polymer consisting of repeating oxymethylene units containing 0.05 to 50 moles of oxyalkylene units per 100 moles of oxymethylene units. (R ₀ : selected from hydrogen, an alkyl group, and a phenyl group, each of which may be the same or different. m: 2 to 6) is an acetal copolymer having the inserted structure, and has the general formula (B) The content of siloxane-alkyleneoxy polymer units having the structure represented by is 0.2 to 40% by weight, and the number average molecular weight is 10000.
500,000. Furthermore, the present invention involves homopolymerizing formaldehyde in the presence of a polymer having one or two hydroxyl groups, carboxyl groups, or amino groups at the terminals of the siloxane-alkylene oxide polymer, or formaldehyde, trioxane, and polyoxy The present invention relates to a method for producing a novel block copolymer characterized by copolymerizing a compound selected from the group consisting of methylene and a cyclic ether. The block copolymer of the present invention has a coefficient of friction of 0.15.
~0.30 value and surface electrical resistance 1×10 ¹⁰ ~5×
It has a value of 10 ¹⁵ Ω, and has unprecedented excellent lubrication performance and antistatic performance. These excellent performances are based on the block structure of the acetal polymer unit and siloxane alkylene oxide polymer unit of the present invention.
At the same time, this block structure is based on a siloxane-alkylene oxide polymer with molecular weight regulating functions. Therefore, it goes without saying that the block copolymer of the present invention has a desired molecular weight. Demand for polyacetal as an engineering plastic has been increasing in recent years.
Improvements in the lubricating performance and antistatic performance of polyacetal have great industrial significance. Next, the block copolymer of the present invention will be specifically explained. The block copolymer of the present invention consists of an acetal polymer unit (A) and a general formula (B). (R ₁ : Selected from hydrogen, alkyl group, and phenyl group, each of which may be the same or different. R ₂ : Selected from hydrogen, an alkyl group, and phenyl group, each of which may be the same or different. X: oxygen, methylene group a: 1-1000 b: 1-1000 n: 2-6) -A triblock copolymer. Here, the acetal polymer includes an acetal homopolymer and an acetal copolymer. An acetal homopolymer is a polymer consisting of repeating oxymethylene units (CH ₂ O-). Acetal copolymers are oxyalkylene units in a chain consisting of oxymethylene units. (R ₀ : selected from hydrogen, an alkyl group, and a phenyl group, each of which may be the same or different.
m=2-6) It is a polymer having a randomly inserted structure. The insertion rate of oxyalkylene units in the acetal copolymer is 0.05 to 50 mol, more preferably 0.1 to 20 mol, per 100 mol of oxymethylene units. Examples of oxyalkylene units include oxyethyne units, oxypropylene units, oxytrimethylene units, oxytetramethylene units, oxybutylene units, oxyphenylethylene units, and the like. Among these oxyethylene units, from the viewpoint of improving the physical properties of the graft copolymer, oxyethylene units - [(CH ₂ ) ₂ O-] and oxytetraethylene units - [(CH ₂ ) ₄ O-] are particularly preferred. preferable. The siloxane-alkylene oxide polymer constituting the block copolymer of the present invention has the general formula As shown, it is a block copolymer of a siloxane units and b alkylene oxide units, and each component is bonded with X (oxygen or methylene group). Here a and b are 1~
Selected from among 1000. When a is 0, the lubrication performance becomes extremely poor. Furthermore, when b is 0, the antistatic performance is significantly reduced. On the other hand, when a is 1000 or more, the strength and rigidity of the block copolymer with the acetal polymer are greatly reduced. b is 1000
The same applies to the above cases. Here, specific examples of siloxane-alkylene oxide polymers are as follows. Dimethylsiloxane-ethylene oxide copolymer (a=50, b=150, X=element) Dimethylsiloxane-ethylene oxide/propylene oxide copolymer (a=10, b=100, X
= methylene group, ethylene oxide/propylene oxide = 1/1 <weight ratio>) Dimethylsiloxane-propylene oxide copolymer (a = 30, b = 200, X = oxygen) Diphenylsiloxane-ethylene oxide copolymer (a = 10 , b=800, x=oxygen) Methylphenylsiloxane-styrene oxide copolymer (a=5, b=30, x=methylene group) Dimethylsiloxane-ethylene oxide/styrene oxide copolymer (a=250, b= 15, x=
Oxygen, ethylene oxide/styrene oxide =
14/1<weight ratio>) The content of siloxane-alkylene oxide polymer in the block copolymer is 0.2 to 40% by weight.
It is necessary to be within the range of If the content of the siloxane-alkylene oxide polymer is too low, the lubrication and antistatic properties of the block copolymer will be poor. On the other hand, if the content is too high, the strength and rigidity of the block copolymer will decrease. The number average molecular weight of the block copolymer of the present invention is
It must be in the range of 10000 to 500000.
The lower limit of the number average molecular weight is determined by the physical properties of the block copolymer, and the upper limit by the moldability of the block copolymer. The number average molecular weight of the block copolymer is determined by the following method. In other words, the number average molecular weight is 100000
In the following cases, use the osmotic pressure method or end group determination method, and if the number average molecular weight is 100,000 or more,
The number average molecular weight is determined by combining the weight average molecular weight determined by the light scattering method and the elution curve determined by the gel permeation chromatography method (GPC method). The block copolymer of the present invention is a block copolymer of an acetal polymer unit (A) and a siloxane-alkylene oxide polymer unit (B),
It has the structure A-B or A-B-A. The structure of the block copolymer of the present invention is confirmed by the following method. That is, when a block copolymer is hydrolyzed in an acidic aqueous solution, the portion consisting of repeating oxymethylene units in the acetal polymer becomes formaldehyde, and the portion of oxyalkylene units inserted into the acetal copolymer becomes alkylene glycol. becomes. Formaldehyde and alkylene glycol are analyzed and quantified using means such as gas chromatography and liquid chromatography. In addition, in the siloxane-alkylene oxide polymer contained in the block copolymer, the bond between the acetal polymer and the siloxane-alkylene oxide polymer and the bond between the polysiloxane and polyalkylene oxide are broken, so that the siloxane oligomer, linear siloxane Decomposed into oligomers and polyalkylene oxides. These compounds are also analyzed and quantified by gas chromatography, liquid chromatography, etc. Next, the method for producing the block copolymer of the present invention will be described. The block copolymer of the present invention has the general formula (R ₁ : Selected from hydrogen, alkyl group, and phenyl group, each of which may be the same or different. R ₂ : Selected from hydrogen, an alkyl group, and phenyl group, each of which may be the same or different. a: 1 to 1000 b: 1 to 1000 n: 2 to 6) A siloxane-alkylene oxide polymer having a structure represented by the following formula, with one or two hydroxyl groups, carboxyl groups, or amino groups at the terminals. It can be obtained by homopolymerizing formaldehyde, or by copolymerizing a cyclic ether with a compound selected from the group consisting of formaldehyde, trioxane and polyoxymethylene. Here, the siloxane-alkylene oxide copolymer functions as a molecular weight regulator during homopolymerization and copolymerization, and at the same time controls the molecular weight of the polymer.
It is incorporated into the polymer as a blocking macromer. The siloxane-alkylene oxide copolymer used as a molecular weight modifier in the present invention is
It is necessary that the polymer has one or two hydroxyl groups, carboxyl groups, or amino groups at the end. When a polymer having one hydroxyl group, carboxyl group, or amino group at the end is used, an A-B type block copolymer is produced; In this case, an ABA type block copolymer is produced. When one hydroxyl group, carboxyl group, or amino group is located at the end of the polymer, these functional groups can be located on either the polysiloxane side or the polyalkylene oxide side. However, from the viewpoint of strengthening the bond between the acetal and the siloxane-alkylene oxide polymer, 1
The functional groups are preferably located on the polyalkylene oxide side. Specific examples of siloxane-alkylene oxide polymers used as molecular weight modifiers are as follows. Dimethylsiloxane-ethylene oxide copolymer (a=50, b=150, x=oxygen, 1 hydroxyl group) Dimethylsiloxane-ethylene oxide/propylene oxide copolymer (a=10, b=100, x
= methylene group, ethylene oxide/propylelene oxide = 1/1 <weight ratio>, 2 hydroxyl groups) Dimethylsiloxane-propylene oxide copolymer (a = 10, b = 800, x = oxygen, 2 hydroxyl groups) Diphenylsiloxane -Ethylene oxide copolymer (a=10, b=800, x=oxygen, 1 carboxyl group) Methylphenylsiloxane-styrene oxide copolymer (a=5, b=30, x=methylene group, 1 hydroxyl group) , one amino group) Dimethylsiloxane-ethylene oxide/styrene oxide copolymer (a=250, b=15, x=
Oxygen, ethylene oxide/styrene oxide =
14/1 <weight ratio>, 1 hydroxyl group, 1 carboxyl group) In addition to these diblock copolymers, in the present invention, ( _R2 ': selected from hydrogen, alkyl group, and phenyl group, each of which may be the same or different. b': 1 to 1000 n': 2 to 6) Siloxane-alkylene having the structure represented by It is also possible to use oxide triblock copolymers as molecular weight regulators. Specific examples of this triblock copolymer are as follows. Dimethylsiloxane-ethylene oxide copolymer (a=50, b=150, b'=150, x=oxygen, 2 hydroxyl groups) Dimethylsiloxane-ethylene oxide/propylene oxide copolymer (a=10, b=100,
b′=100, x=methylene group, ethylene oxide/
Propylene oxide = 1/1 <weight ratio>, 2 hydroxyl groups) These siloxane-alkylene oxide polymers are preferably purified by washing, adsorption, drying, etc. prior to polymerization. Moreover, these siloxane-alkylene oxide polymers can be used alone, or two or more kinds can be mixed and subjected to polymerization. In the homopolymerization of the present invention, sufficiently purified formaldehyde is used, and in the copolymerization, sufficiently purified formaldehyde, trioxane, polyoxymethylene, and cyclic ether are used as starting materials for the acetal polymer. Here, polyoxymethylene is a homopolymer of formaldehyde or trioxane, and has a number average molecular weight of 10,000 to 500,000, preferably 30,000.
~150,000. The first group of cyclic ethers has the general formula

[Formula] (R ₀ : selected from hydrogen, an alkyl group, and a phenyl group, each of which may be the same or 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(chloromethyl)oxetane, tetrahydrofuran, oxepane, and the like. Among these alkylene oxides, ethylene oxide is particularly preferred. The second group of cyclic ethers has the general formula

There is a cyclic formal represented by the formula. For example, ethylene glycol formal,
Propylene glycol formal, diethylene glycol formal, triethylene glycol formal, 1,4-butanediol formal,
1,5-pentanediol formal, 1,6-
There is hexanediol formal. Among these cyclic formals, ethylene glycol formal, diethylene glycol formal and 1,4-butanediol formal are particularly preferred. Cyclic ether is based on 100 parts by weight of formaldehyde, trioxane, and polyoxymethylene.
0.03 to 100 parts by weight, more preferably 0.1 to 50 parts by weight are used. An anionic polymerization catalyst and a cationic polymerization catalyst are used in the homopolymerization and copolymerization of the present invention. Typical groups of anionic polymerization catalysts include alkali metals such as sodium and potassium, alkali metal complexes such as sodium-naphthalene and potassium-anthracene, alkali metal hydrides such as sodium hydride, and alkaline earths such as calcium hydride. metal hydrides, alkali metal alkoxides such as sodium methoxide and potassium t-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 - Amines such as butylamine, diethylamine, trioctylamine, pyridine, quaternary ammonium salts such as ammonium stearate, tetrabutylammonium methoxide, dimethyldistearylammonium acetate, tetramethylphosphonium propionate, trimethylbenzylphosphonium ethoxide, etc. , tetravalent organic tin compounds such as tributyltin chloride, diethyltin dilaurate, and dibutyltin dimethoxide, and alkyl metals such as n-butyllithium and ethylmagnesium chloride. Cationic polymerization catalysts include tin tetrachloride, tin tetrabromide, titanium tetrachloride, aluminum trichloride, zinc chloride, vanadium trichloride, antimony pentafluoride, boron trifluoride, boron trifluoride diethyl etherate,
So-called Friedel-Crafts type compounds such as boron trifluoride coordination compounds such as boron trifluoride acetic anhydrate and boron trifluoride triethylamine complex compounds, perchloric acid, acetyl perchlorate, hydroxyacetic acid, trichloroacetic acid, Inorganic and organic acids such as p-toluenesulfonic acid, complex salt compounds such as triethyloxonium tetrafluoroborate, triphenylmethylhexafluoroantimonate, allyldiazonium hexafluorophosphate, allyldiazonium tetrafluoroborate, diethylzinc, triethyl aluminum,
Examples include alkyl metals such as diethylaluminium chloride. These anionic polymerization catalysts and cationic polymerization catalysts are used in an amount of 0.0005 to 5 parts by weight based on 100 parts by weight of the starting material. Homopolymerization or copolymerization is
It is carried out without a solvent or in an organic medium. 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, benzene, toluene,
Examples include aromatic hydrocarbons such as 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 siloxane-alkylene oxide polymer, which is a molecular weight regulator, is used after being uniformly dissolved or dispersed in the reaction system. The concentration of the molecular weight modifier in the system can be readily determined experimentally depending on the molecular weight requirements of the desired block copolymer. The polymerization temperature is usually set between -20 and 230°C, but preferably between 20 and 210°C in the case of no solvent, and -10 to 120°C in the case of using an organic medium.
It is more preferable. There are no particular restrictions on polymerization time, but from 5 seconds to
Set between 300 minutes. After a predetermined period of time has elapsed, a terminator is added to the reaction system to complete the polymerization. The obtained polymer is stabilized by removing unstable ends by hydrolysis or blocking unstable ends by a method such as esterification. The stabilized block copolymer is
Stabilizers and the like are added and used for practical use. The features of the block copolymer of the present invention and its production method which have been described in detail above are listed below. (1) The block copolymer has excellent lubrication performance and antistatic performance. (2) By using a specific siloxane-alkylene oxide polymer, excellent performance can be imparted to the block copolymer, and at the same time, the molecular weight of the polymer can be controlled arbitrarily. Measurement items in the following examples are as follows. MI: Add 2,2-methylene-bis(4-
Methyl-6-tert-butylphenol) 0.25 parts,
0.50 parts of nylon 6-6 was added and pelletized using a 50 mmφ extruder. The MI of this pellet is
Measured according to ASTM-D 1238-57T. MI is a measure of molecular weight. Friction coefficient: The above pellet was formed into a flat plate, and the friction coefficient of this flat plate was measured using a thrust type friction and wear tester under the following conditions. Mating material: Metal (S45C) Load: 10Kg/cm ² -line speed: 12cm/sec. The wear coefficient is an index of lubrication performance. Surface electrical resistance: The above pellet is formed into a flat plate, and the surface electrical resistance of this flat plate is determined at 20°C and 50% R.
Measured under H. Surface electrical resistance is an indicator of antistatic performance. Example 1 (1) Production method of block copolymer Formaldehyde with a purity of 99.9% per hour
A dimethylsiloxane-ethylene oxide copolymer (hereinafter referred to as ethylene oxide copolymer having the following structure) was added as a molecular weight regulator at a ratio of 100 parts (hereinafter, parts indicate parts by weight).
DMS-EO copolymer) was continuously fed for 3 hours into 500 parts of toluene containing 2.5×10 ⁻⁴ mol/dimethyl distearyl ammonium acetate as a polymerization catalyst. DMS-EO copolymer: At the same time as formaldehyde gas supply, 20g/
Toluene containing DMS-EO copolymer and dimethyl distearyl ammonium acetate at a rate of 2.5×10 ^-4 mol./hour was also continuously fed for 3 hours at a rate of 500 parts per hour. Formaldehyde gas was also continuously supplied at a rate of 100 parts per hour for 3 hours, during which time the polymerization temperature was maintained at 60°C. 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 hot toluene, it was vacuum dried at 60°C to obtain 308 parts of a white polymer. (2) Confirmation of structure of block copolymer 500 parts of the polymer obtained in (1) was dispersed in 95 parts of 0.3N hydrochloric acid aqueous solution and heated at 98°C for 3 hours. Through this heating operation, all of the acetal polymer consisting of oxymethylene chains returned to formaldehyde. Note that the amount of formaldehyde was 4.50 parts.
Further, this solution contained 0.20 part of polyethylene glycol (n 1780) and 0.42 part of cyclic siloxane and chain siloxane in terms of polydimethylsiloxane. After acetylating the polymer obtained in (1), terminal group analysis and quantitative analysis using infrared absorption spectroscopy revealed that terminal acetyl group/CH ₂ O chain 75×10 ^-5 mol./
Obtained the value of mol. From this fact, n of the acetal polymer in the block copolymer in (1) is 4.0×
It became clear that 10 ⁴ . From the above analysis results, it became clear that the polymer obtained in (1) was a block copolymer of dimethylsiloxane-ethylene oxide polymer and acetal having the following structure. In addition, the content of siloxane-alkylene oxide polymer in this block copolymer is 10.1
Weight%. (3) Measurement of physical properties of block copolymer When a stabilizer was added to a polymer that had been terminally stabilized using acetic anhydride and molded, a very tough molded product was obtained. The physical properties of this molded article are as follows. MI 12.0 (g/10 min) Coefficient of friction 0.22 Surface electrical resistance 8×10 ¹² (Ω) As described above, this block copolymer has a desired molecular weight and is excellent in lubrication performance and antistatic performance. Example 2 (4) Production method of block copolymer Formaldehyde was used as a molecular weight regulator at a ratio of 100 parts/hr and ethylene oxide at a ratio of 2.2 parts/hr.
31g/dimethylsiloxane-ethylene oxide copolymer (hereinafter referred to as EO-DMS) having the following structure:
-EO copolymer) was continuously fed into 500 parts of toluene for 5 hours. EO-DMS-EO copolymer Toluene containing the EO-DMS-EO copolymer at the above concentration was also continuously supplied at a rate of 500 parts/hr for 5 hours. Additionally, as polymerization catalysts, tetrabutylammonium acetate and boron trifluoride dibutyl etherate were continuously supplied through separate conduits at a rate of 0.03 parts/hr and 0.06 parts/hr, respectively, and the polymerization temperature was maintained at 60°C during this period. Maintained. The polymer was separated from toluene, then washed and dried to obtain 520 parts of a polymer. (5) Confirmation of structure of block copolymer The polymer obtained in (4) was hydrolyzed under the same conditions as in Example 1 to obtain a formaldehyde content of 4.24 parts. Furthermore, by quantifying the amount of ethylene glycol in the hydrolysis solution, the insertion rate of oxyethylene units in the acetal polymer was determined to be 1.5 mol./100 mol.
Results with CH ₂ O chains were obtained. Further, this hydrolyzed solution contained 0.37 parts of polyethylene glycol (n 1780) and 0.39 parts of a siloxane compound in terms of polydimethylsiloxane. After acetylating the polymer obtained in (4), the terminal acetyl group was analyzed and quantified, and a value of terminal acetyl group/CH ₂ O chain = 150 × 10 ^-5 mol./mol. was obtained. Ta. From this fact, it was found that n of the acetal polymer of polymer (4) was 4.0×10 ⁴ . From the above analysis results, it became clear that the polymer obtained in (4) had the following structure. X ₁ = - [(CH ₂ O -) ₆₇₀ - (CH ₂ CH ₂ O -) -] ₁₀ H (Here, X ₁ = - [(CH ₂ O -) ₆₇₀ - (CH ₂ CH ₂ O -)
―] ₁₀ H is 10 in 670 oxymethylene units.
This shows that oxyethylene units are randomly inserted. ) The content of siloxane alkylene oxide polymer in this block copolymer was 15.3% by weight. (6) Measurement of physical properties of block copolymer The polymer obtained in (4) has the following physical properties. MI 10.8 (g/10 min) Coefficient of friction 0.22 Surface electrical resistance 1×10 ¹² (Ω) This block copolymer is also a novel polymer with a desired molecular weight and excellent lubrication and antistatic performance. Example 3 (7) Method for producing block copolymer Polyoxymethylene sufficiently dried under reduced pressure
5.02Kg, ethylene glycol formal 420g,
As a molecular weight regulator, 1.26 kg of diphenylsiloxane-ethylene oxide/propylene oxide copolymer having the following structure and 50 kg of hexane were charged into a reaction tank. After charging, the contents of the reaction tank were heated to 70° C., and then 1.27 g of boron trifluoride dibutyl etherate was added to the reaction tank to start the reaction. After maintaining the internal temperature of the reaction vessel at 70℃ for 32 minutes,
g of tributylamine was added to stop the reaction. After the polymer was filtered off, it was washed five times with a large amount of methanol, and 6.48 kg of polymer was recovered. (8) Confirmation of structure of block copolymer As a result of hydrolysis of 5.00 parts of the polymer obtained in (7), the following results were obtained. Formaldehyde amount: 4.07 parts Oxyethylene unit insertion rate: 1.52 mol./100 mol.
CH ₂ O chain polyethylene/propylene copolymer (n 2940) 0.40 parts Siloxane compound (polydiphenylsiloxane equivalent) 0.54 parts In addition, after acetylating the polymer obtained in (7), the end group amount was determined. The Mn of the acetal polymer of the polymer was found to be 3.0×10 ⁴ . From the above results, it became clear that the polymer obtained in (7) had the following structure. X ₂ =—[(CH ₂ O—) ₁₀₀ —(CH ₂ CH ₂ O—) _1.5 —]H (Here, X ₂ =—[(CH ₂ O—) ₁₀₀ —(CCH ₂ CH ₂ O—) _{1 .
5-} ]H indicates that 1.5 oxyethylene units are randomly inserted into 100 oxyethylene units. ) The content of siloxane-alkylene oxide polymer in this block copolymer is 18.7% by weight. (9) Measurement of physical properties of block copolymer The polymer obtained in (7) has the following physical properties. MI 24.2 (g/10 min) Friction coefficient 0.26 Surface electrical resistance 5×10 ¹² (Ω) This block copolymer also has a desired molecular weight and has excellent lubrication and antistatic performance. Example 4 (10) Production method of block copolymer In a kneader with two Σ-type stirring blades, 500 parts of sufficiently purified trioxane, 10 parts of ethylene oxide, and a dimethylsiloxane-ethylene oxide copolymer having the following structure as a molecular regulator were added.
121 parts were charged and heated to 70°C. Then, 0.40 part of boron trifluoride dibutyl etherate was added to this kneader and stirred for 35 minutes. 35
After 15 minutes, 15 parts of tributylamine was added to stop the polymerization. The contents were taken out from the kneader, thoroughly washed with hot toluene, and 568 parts of polymer were recovered. (11) Confirmation of structure of block copolymer The polymer obtained in (10) was confirmed to have the following structure as a result of hydrolysis and infrared absorption spectrum analysis. X ₃ =—[(CH ₂ O—) ₃₀₀ —(CH ₂ CH ₂ O—) ₆ —]H (where X ₃ =—[(CH ₂ O—) ₃₀₀ —(CH ₂ CH ₂ O—) ₆
--]H indicates that 6 oxyethylene units are randomly inserted into 300 oxymethylene units. ) The content of siloxane-alkylene oxide polymer in this block copolymer is 19.5% by weight. (12) Measurement of physical properties of block copolymer The polymer obtained in (11) has the following physical properties. MI 21.8 (g/10 min) Coefficient of friction 0.23 Surface electrical resistance 1×10 ¹² (Ω) This block copolymer also has a desired molecular weight and has excellent lubrication and antistatic performance. Comparative Example 1 (method of Japanese Patent Publication No. 35-2194) (13) Production of polymer Instead of the siloxane-alkylene oxide polymer used in Example 1, polytetramethylene glycol (N 7200) was used at a concentration of 20.0 g/ Except for the use of polymer 320, all operations were performed in the same manner as in Example 1.
I got the department. (14) Confirmation of the structure of the polymer When the structure of the polymer obtained in (13) was analyzed using the same method as in Example 1, the presence of the following two types of polymers was confirmed. HO (CH ₂ O―) _1310-C ― [(CH ₂ ) ₄ O―] ₁₀₀ ― (CH ₂ O―
) _c
H (E) HO―[―(CH ₂ ) ₄ O―] ₁₀₀ ―(CH ₂ O―) ₁₃₁₀ H (F) (c=1 to 1309) (15) Measurement of physical properties of polymer Obtained in (13) The physical properties of the polymer are as follows. MI 12.5 (g/10 min) Coefficient of friction 0.35 Surface electrical resistance 8×10 ¹² (Ω) Molecular weight can be adjusted by using polytetramethylene glycol, but the lubrication and antistatic properties of this polymer are poor. It is. The physical properties of the molded product obtained from the acetal homopolymer HO-(CH ₂ O-) _1310H are as follows. MI 12.0 (g/10 min) Friction coefficient 0.36 Surface electrical resistance >10 ¹⁶ (Ω) Also obtained from acetal copolymer HO―[―(CH ₂ O―) ₁₃₁₀ ―(CH ₂ CH ₂ O―) ₂₀ ―]H The physical properties of the molded product are as follows. MI 12.8 (g/10 min) Friction coefficient 0.36 Surface electrical resistance >10 ¹⁶ (Ω) Examples 5 to 11 Using starting materials as shown in Table 1 and siloxane-alkylene oxide polymers, block copolymers shown in Table 1 were prepared. I got it. These block copolymers are all new polymers and have excellent lubrication and antistatic properties. Further, each polymer has a desired molecular weight. Comparative Examples 2 and 3 (Method of Japanese Patent Publication No. 35-2194) Block copolymers shown in Table 1 were produced using starting materials and polymers having active hydrogen atoms as shown in Table 1. When a polymer having mere active hydrogen atoms is used as a molecular weight modifier, it is not possible to simultaneously improve the lubricating performance and the antistatic performance.

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Claims (1)

[Claims] 1. Acetal polymer unit (A) and general formula (B) (R ₁ : Selected from hydrogen, alkyl group, and phenyl group, each of which may be the same or different. R ₂ : Selected from hydrogen, an alkyl group, and phenyl group, each of which may be the same or different. X: oxygen, methylene group a: 1-1000 b: 1-1000 n: 2-6) -A triblock copolymer, wherein the acetal polymer unit (A)
is an acetal homopolymer consisting of repeating oxymethylene units (CH ₂ O-) or a polymer consisting of repeating oxymethylene units in an amount of 0.05 to 50 mol per 100 mol of oxymethylene units and oxymethylene units. oxyalkylene unit (R ₁ : selected from an alkyl group and a phenyl group, each of which may be the same or different. m: 2 to 6) is an acetal copolymer having a structure inserted therein, and is represented by the general formula (B). The content of siloxane-alkylene oxide polymer units having a structure of 0.2 to 40% by weight, and a number average molecular weight of
Novel block copolymer between 10,000 and 500,000 2 General formula (R ₁ : Selected from hydrogen, alkyl group, and phenyl group, each of which may be the same or different. R ₂ : Selected from hydrogen, an alkyl group, and phenyl group, each of which may be the same or different. X: oxygen, methylene group a: 1 to 1000 b: 1 to 1000 n: 2 to 6) One hydroxyl group, carboxyl group, or amino group at the end of the siloxane-alkylene oxide polymer having the structure represented by Or a novel method characterized by homopolymerizing formaldehyde or copolymerizing a cyclic ether with a compound selected from the group consisting of formaldehyde, trioxane and polyoxymethylene in the presence of a polymer having two of them. Production method of block copolymer.