JP4192862B2 - Method for producing polyether copolymer - Google Patents

Description

The present invention relates to a method for producing a polyether polymer. In particular, the present invention relates to a method for producing a polyether copolymer in which an oxirane compound having an ethylenically unsaturated group and an oxirane compound not containing an ethylenically unsaturated group are copolymerized using a catalyst.

Polyether polymers become polymers with various properties by selecting the type of oxirane compound used as a raw material, so rubber parts for automobiles, rubber parts for electric and electronic devices, polymers for various plastic blends, It is used in a very wide range of fields such as molecular solid electrolytes. The industrial production methods for polyether polymers include the oxirane compound and a solution polymerization method in which the oxirane compound is polymerized in an organic solvent in which the polymer is soluble, and the oxirane compound is polymerized in an organic solvent in which the polymer is insoluble. There is known a suspension precipitation polymerization method in which a granular polymer is precipitated. Catalysts that can polymerize oxirane compounds include reaction products of alkylzinc and water, reaction products of organotin compounds and phosphate esters, reaction products of alkylaluminum and water, and reaction products of alkylaluminum and water and chelate compounds. It is known to use a product, a reaction product of an alkylaluminum and a phosphoric acid compound.

A polyether polymer having a crosslinkable ethylenically unsaturated group can be molded by crosslinking with sulfur, peroxide or the like to impart mechanical strength. However, when a polymer containing this crosslinkable reactive functional group is produced, if an oxirane compound having an ethylenically unsaturated group is used even in an inert gas atmosphere such as nitrogen or helium, polymerization is performed. Sometimes a cross-linked product is formed. The cross-linked product means a three-dimensional polymer that is insoluble in a solvent. Formation of a cross-linked product is promoted by a high polymerization temperature, reaction heat generated rapidly, and reaction time. When a copolymer containing a large amount of such a cross-linked product is used, processability is significantly impaired. In the production of a polyether polymer using an organoaluminum compound as a catalyst (Japanese Patent Laid-Open No. 2003-138003), a Lewis basic substance having no active hydrogen is added to the polymerization system in order to suppress the formation of a crosslinked product. Although the content of the cross-linked product is reduced, it is necessary to further reduce the generation of the cross-linked product.
JP 2003-138003 A

The problem to be solved is to provide a method for producing a polyether-based copolymer with little formation of a cross-linked product.

The present inventors do not include an oxirane compound having an ethylenically unsaturated group and an ethylenically unsaturated group in the presence of a compound having a phenol structure in which both of the ortho positions are substituted with a tert-butyl group. The present invention was completed by finding that the formation of a crosslinked product can be reduced by copolymerizing an oxirane compound.

By using the production method according to the present invention, it is possible to produce a polyether copolymer with little production of a cross-linked product. Since this also has a favorable effect on moldability, it can be suitably used in a very wide range of fields such as automotive rubber parts, rubber members for electric and electronic devices, polymers for various plastic blends, and polymer solid electrolytes.

The compound having a phenol structure in which both of ortho positions used in the present invention are substituted with tert-butyl groups has a structure in which tert-butyl groups are present at two ortho positions immediately adjacent to the hydroxyl groups of each benzene ring. Specifically, 2,6-di-tert-butyl-phenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4- Ethylphenol, 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4- Hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine, tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propione G] 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4) -Hydroxyphenyl) propionate, N, N'-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 3,5-di-tert-butyl-4-hydroxybenzylphos Phonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-tert-butyl -4-hydroxybenzyl) isocyanurate, isooctyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, etc. It can be mentioned, and they may be used alone or in combination of two or more. Among these, in particular, 2,6-di-tert-butyl-phenol, 2,6-di-tert-butyl-4-methylphenol, tetrakis [methylene-3- (3,5-di-tert-butyl -4-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris (3,5-di -Tert-butyl-4-hydroxybenzyl) isocyanurate is preferred from the standpoint of availability.

The amount of the compound having a phenol structure is preferably in the range of 0.01 to 10 parts by weight of the compound having a phenol structure with respect to 100 parts by weight of the total oxirane compound. When it is more than 10 parts by weight, the mechanical properties of the polymer are lowered.

As described in JP-A-63-1554736, a polymerization method for a polyether copolymer containing a crosslinkable ethylenically unsaturated group is used as a catalyst for ring-opening polymerization of an oxirane compound and water. Reaction products of organotin compounds and phosphate esters, reaction products of alkylaluminum and water, reaction products of alkylaluminum and phosphate compounds, etc., in the presence of an organic solvent. Or it can obtain by making it react under stirring at reaction temperature 10-80 degreeC in absence.

The method for producing a polyether-based copolymer according to the present invention includes a solution polymerization method in which an oxirane compound is polymerized in an organic solvent in which the oxirane compound and the copolymer are soluble in the presence of the catalyst, or a copolymer is used. This is a suspension precipitation polymerization method in which an oxirane compound is polymerized in an insoluble organic solvent to precipitate a particulate polymer.

The oxirane compound may be soluble or insoluble in an organic solvent, but it is preferable that at least a part of the oxirane compound is soluble. Examples of such solvents include aliphatic hydrocarbons such as hexane, heptane, cyclohexane, and octane; aromatic hydrocarbons such as benzene, toluene, and xylene; ethers such as diethyl ether, methylbutyl ether, and dimethoxyethane. And can be appropriately selected according to the type of oxirane compound used and the polymerization temperature. Preferably, aliphatic hydrocarbons are used.

The mixing ratio of the oxirane compound, the organic solvent and the catalyst is usually preferably in the range of 100 to 1000 parts by weight of the organic solvent and 0.01 to 10 parts by weight of the catalyst with respect to 100 parts by weight of the total oxirane compound. The polymerization temperature is not particularly limited, but is usually in the range of −20 ° C. to 70 ° C., and is appropriately selected according to the activity of the catalyst, the organic solvent used, and the type of oxirane compound. The polymerization is usually carried out with stirring.

Examples of oxirane compounds that can be polymerized include alkylene oxides such as ethylene oxide, propylene oxide, butene oxide, and isobutylene oxide; epichlorohydrin, epibromohydrin, methacrylic chloride oxide, trifluoromethylethylene oxide, dichloroisobutylene oxide, styrene oxide, Substituted alkylene oxides: phenyl glycidyl ether, chloroethyl glycidyl ether, methyl glycidyl ether, ethyl glycidyl ether, butyl glycidyl ether, 2-methoxyethyl glycidyl ether, 2- (2-methoxyethoxy) ethyl glycidyl ether, cyclohexyl glycidyl ether, benzyl Glycidyl ethers such as glycidyl ether and ethylenically unsaturated groups Combination of oxirane compounds and the like.

Examples of the oxirane compound having an ethylenically unsaturated group include allyl glycidyl ether, allyl phenyl glycidyl ether, vinyl glycidyl ether, 4-vinylcyclohexyl glycidyl ether, α-terpinyl glycidyl ether, cyclohexenyl methyl glycidyl ether, p- Glycidyl ethers such as vinylbenzyl glycidyl ether, 2-vinyloxyethyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, glycidyl sorbate, glycidyl cinnamate, glycidyl crotonate, 3,4-epoxy- Examples thereof include alkenyl epoxides such as 1-butene, 3,4-epoxy-1-pentene, and 4,5-epoxy-2-pentene. When the content of the oxirane compound having an ethylenically unsaturated group in the polyether copolymer exceeds 30 mol%, the processability is remarkably lowered, and therefore the content is preferably less than this.

Reaction product of alkylzinc and water or alcohol, reaction product of organotin compound and phosphate ester, reaction product of alkylaluminum and water, reaction product of alkylaluminum and water and chelate compound, alkylaluminum and phosphate compound In an ionic ring-opening polymerization of an oxirane compound using, for example, a catalyst, a compound having a phenol structure sandwiched between two tert-butyl groups, which are bulky substituents, reacts with a polymerization active site. Since the polymerization reaction is very rarely stopped, the polymerization activity is not lowered. The compound having the phenol structure does not significantly reduce the molecular weight of the copolymer. On the other hand, a compound having a phenol structure can react with radicals present in the polymerization system, as used as a radical polymerization inhibitor, and the ethylenically unsaturated groups present in the oxirane compound or copolymer can be reacted with each other. As a result, formation of a cross-linked product insoluble in a solvent is reduced.

In the production method of the present invention, the addition timing and addition method of the compound having a phenol structure are not particularly limited. For example, they may be added all at once immediately after the start of polymerization, or may be added sequentially while tracking the reaction of the oxirane compound. In the polymerization system, a compound having a phenol structure is added after being dispersed or dissolved in an organic solvent, or only a compound having a solid powdery or liquid phenol structure is added without being dispersed or dissolved in an organic solvent. .

The polymerization is stopped by adding a polymerization terminator such as water or primary alcohol to the polymerization system, and after adding an anti-aging agent, the copolymer is recovered according to a conventional method. Some of the compounds having a phenol structure in which both of the ortho positions added to the polymerization system are substituted with tert-butyl groups adhere to the copolymer and remain in the copolymer. It does not need to be removed because it works as an inhibitor.

Hereinafter, the present invention will be described specifically by way of examples.

<Monomer conversion composition and copolymer molecular weight>
The monomer equivalent composition of the copolymer was determined from the ¹ H NMR spectrum. In the case of a copolymer consisting of ethylene oxide / epichlorohydrin / glycidyl methacrylate, the monomer equivalent composition was determined from the chlorine content and iodine value analysis. The molecular weight of the copolymer was measured by gel permeation chromatography and the molecular weight was calculated in terms of standard polystyrene. Gel permeation chromatography measurement is performed using a measuring device RID-6A manufactured by Shimadzu Corporation, Showex KD-807, KD-806, KD-806M and KD-803, and a solvent dimethylformamide manufactured by Showa Denko K.K. At 60 ° C.

<Measurement of cross-linked product content>
A 2 cm × 2 cm × 2 cm cubic container made of a 100 mesh wire net containing 0.1 g of copolymer was immersed in a glass bottle containing 500 ml of toluene and left at 40 ° C. for 16 hours. The metal mesh container was taken out and dried, and the weight of the residue in the container was measured. The ratio of the weight of the residue to the charged copolymer was calculated as the ratio (%) of the cross-linked product.

A reaction product obtained by heating 0.1 g of tributyltin oxide and 0.3 g of tributyl phosphate as a catalyst at 250 ° C. for 20 minutes in a glass flask having a capacity of 1 L with nitrogen inside, and 1,3,5-trimethyl 0.2 g of -2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 25 g of 2- (2-methoxyethoxy) ethylglycidyl ether adjusted to a water content of 10 ppm or less, allyl 15 g of glycidyl ether and 400 g of n-hexane were charged as a solvent. In order to reduce the block chain in the copolymer, 60 g of ethylene oxide was sequentially added while monitoring the polymerization conversion rate of the oxirane compound by gas chromatography. When the polymerization reaction was carried out for 6 hours with stirring at 20 ° C., the polymerization conversion rate of the total oxirane compound was 98%. After adding methanol to stop the polymerization reaction, 0.3 g of anti-aging agent 4,4′-thiobis (6-tert-butyl-3-methylphenol) was added and further stirred, and solid product was obtained by filtration. Was recovered and dried at 40 ° C. under reduced pressure for 24 hours to obtain a copolymer. The molar composition ratio of the polyether copolymer is ethylene oxide / 2- (2-methoxyethoxy) ethyl glycidyl ether / allyl glycidyl ether = 83/9/8, the content of the cross-linked product is 0.1%, and The weight average molecular weight of the toluene soluble part was 2.0 × 10 ⁶ .

To a glass flask having a volume of 50 ml with the inside replaced with nitrogen, 2.0 g of triisobutylaluminum and 4.0 g of n-hexane were added and stirred uniformly. Phosphoric acid (H ₃ PO ₄
A solution consisting of 0.3 g (corresponding to 100% by weight) and 25.0 ml of diethyl ether was slowly added dropwise so that the reaction temperature was around 5 ° C. Further, 0.1 g of 2,4,6-trimethylpyridine as a nitrogen-containing cyclic compound was added to this reaction solution with stirring, and the mixture was further stirred at 60 ° C. for 1 hour to prepare a catalyst. Epi in which the prepared catalyst, 0.2 g of tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, and water adjusted to 10 ppm or less were prepared in a glass flask having a capacity of 1 L with nitrogen inside. 40 g of chlorohydrin, 10 g of glycidyl methacrylate and 400 g of n-hexane were charged, and 50 g of ethylene oxide was successively added while monitoring the polymerization conversion rate of the oxirane compound by gas chromatography. When the polymerization reaction was carried out for 6 hours with stirring at 20 ° C., the polymerization conversion rate of the total oxirane compound was 99%. After adding methanol to stop the polymerization reaction, 0.3 g of anti-aging agent 4,4′-thiobis (6-tert-butyl-3-methylphenol) was added and further stirred, and the solid product was filtered. Was recovered and then dried under reduced pressure at 40 ° C. for 24 hours to obtain a copolymer. The molar composition ratio of the polyether copolymer was ethylene oxide / epichlorohydrin / glycidyl methacrylate = 70/26/4, the content of the cross-linked product was 0.2%, and the weight average of the toluene soluble part. The molecular weight was 1.5 × 10 ⁶ .
(Comparative Example 1)

The same treatment as in Example 1 except that 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene was not added in Example 1. Thus, a copolymer was obtained. The polymerization conversion of the total oxirane compound is 98%, and the molar composition ratio of the polyether copolymer is ethylene oxide / 2- (2-methoxyethoxy) ethyl glycidyl ether / allyl glycidyl ether = 83/9/8, The content of the cross-linked product was 8.7%, and the weight-average molecular weight of the toluene soluble part was 2.1 × 10 ⁶ .
(Comparative Example 2)

A copolymer was obtained in the same manner as in Example 2 except that tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate was not added. The polymerization conversion of the total oxirane compound is 99%, the molar composition ratio of the polyether copolymer is ethylene oxide / epichlorohydrin / glycidyl methacrylate = 70/26/4, and the content of the cross-linked product is 7. The weight average molecular weight of the toluene-soluble part was 1.4 × 10 ⁶ .
(Comparative Example 3)

In Example 1, instead of 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 4,4′-thiobis (6- A copolymer was obtained in the same manner as in Example 1 except that tert-butyl-3-methylphenol was used. The polymerization conversion of the total oxirane compound is 87%, and the molar composition ratio of the polyether copolymer is ethylene oxide / 2- (2-methoxyethoxy) ethyl glycidyl ether / allyl glycidyl ether = 84/9/7, The content of the cross-linked product was 8.5%, and the weight-average molecular weight of the toluene soluble part was 5.2 × 10 ⁵ .

As is clear from Examples 1 and 2 and Comparative Examples 1, 2 and 3, a compound having a phenol structure in which both of the ortho positions are substituted with tert-butyl groups in the polymerization system is added. When the polymerization is carried out, a copolymer with less generation of a cross-linked product can be obtained without lowering the polymerization conversion rate and the molecular weight of the copolymer.

Claims (4)

1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3 , 5-Di-tert-butylanilino) -1,3,5-triazine, tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, 2,2-thio- Diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N, N ′ Hexamethylene bis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 3,5-di-tert-butyl-4-hydroxyben Ruphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-tert Ethylenic unsaturation in the presence of at least one compound of -butyl-4-hydroxybenzyl) isocyanurate or isooctyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate A method for producing a polyether copolymer comprising copolymerizing an oxirane compound having a group and an oxirane compound not containing an ethylenically unsaturated group. The method for producing a polyether copolymer according to claim 1 , wherein the polyether copolymer contains 0.1% to 30 mol% of a unit composed of an oxirane compound having an ethylenically unsaturated group. Oxirane compound having an ethylenically unsaturated group, allyl glycidyl ether, allyl phenyl glycidyl ether, vinyl glycidyl ether, claim 1 is an acrylic acid glycidyl, glycidyl methacrylate, glycidyl sorbate, glycidyl cinnamate or crotonic acid glycidyl, Or the manufacturing method of the polyether type copolymer of 2 . The method for producing a polyether copolymer according to any one of claims 1 to 3, wherein a catalyst comprising a reaction product of an organotin compound and a phosphate ester compound is used.