JP3109040B2 - Method for producing high molecular weight polyalkylene glycol - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a high molecular weight polyalkylene glycol which is formed into a sheet or film and can be used as a water-soluble packaging material.

[0002]

2. Description of the Related Art Polyalkylene glycols are water-soluble and have been used in various applications taking advantage of their characteristics. As one of them, it is used alone or in combination with various additives to form a sheet or film and used as a packaging material.

In order to use polyalkylene glycol as a molding material, a polyalkylene glycol having a high molecular weight is desirable in order to satisfy practical physical properties.

As a method for producing a high molecular weight polyalkylene glycol by increasing the molecular weight with a chain extender, a method of transesterifying a polyalkylene glycol with a polycarboxylic acid, an anhydride thereof, or a lower alkyl ester thereof is used. (JP-A-59-226018),
In the transesterification reaction, a method using a hydroxide or alkoxide of a specific metal or a complex of a salt of a specific metal with a weak acid or a weak acid as a catalyst (JP-A-5-5031), Method for reacting with polyisocyanate (JP-A-6-329)
No. 76 publication).

[0005]

However, in the conventional method, it takes a long time to sufficiently increase the molecular weight, and even if the molecular weight can be increased, a cross-linking reaction occurs at the same time, causing a problem in the appearance of the molded product. There was a possibility.

The present invention has been made to solve the above problems, and has as its object to provide a method for efficiently producing a high-molecular-weight polyalkylene glycol suitable for molding in a short time. .

[0007]

The present inventors have studied the production of a high molecular weight polyalkylene glycol, and as a result, have found that a polyalkylene glycol having a water content of 1000 ppm or less can be used to prepare a chain extender. It has been found that high molecular weight polyalkylene glycol can be efficiently produced by adding the compound to increase the molecular weight. Although polyalkylene glycols are hydrophilic and usually contain about several percent of water, conventional methods for producing high-molecular-weight polyalkylene glycols using a chain extender include information on controlling the amount of water in the polyalkylene glycol. No method has been proposed so far in which a polyalkylene glycol having a water content of a certain amount or less is reacted with a chain extender.

[0008] The present invention, when a high molecular weight polyalkylene glycol with a chain extender, Polya used
A method for producing a high-molecular-weight polyalkylene glycol, which comprises degassing the alkylene glycol under heat and melting to reduce the water content of the polyalkylene glycol to 1000 ppm or less.

In particular, the present invention is effective when the chain extender is one or more compounds selected from the group consisting of (sub) phosphoric acid esters and polyfunctional anhydrides.

Hereinafter, the present invention will be described in more detail.

The polyalkylene glycol used in the present invention is not particularly limited. Examples thereof include polyethylene glycol, polypropylene glycol, polytetraethylene glycol, polyepichlorohydrin, and copolymers thereof. .

The water content of the polyalkylene glycol used in the present invention is 5000 ppm or less, preferably 2000 ppm or less, more preferably 1000 pp.
m or less. If it exceeds the above range, there arises a problem that the high molecular weight by the chain extender does not efficiently occur.

The method of adjusting the water content of the polyalkylene glycol to be used is not particularly limited, and for example, a method of degassing the polyalkylene glycol to be used under heating and melting is used.

The chain extender used in the present invention is not particularly limited as long as it is a generally known chain extender.
Phosphate ester, phosphite ester, polyfunctional acid anhydride,
Examples thereof include polyfunctional isocyanates, epoxy compounds, oxazoline compounds and the like, and one or more of these may be used.

The phosphate and / or phosphite may be a diester or a triester. Examples of the ester group include a methyl group, an ethyl group, a propyl group, a butyl group, a phenyl group and a 2-ethylhexyl group. And the like, and one or more of these compounds can be used. In consideration of reactivity and economy, a methyl group, an ethyl group or a phenyl group is preferable among the ester groups.

The polyfunctional acid anhydride is not particularly restricted but includes, for example, pyromellitic dianhydride, benzophenonetetracarboxylic dianhydride, butane-1,2,3,4-
Tetracarboxylic dianhydride, maleic anhydride homopolymer, maleic anhydride-vinyl acetate copolymer, maleic anhydride-ethylene copolymer, maleic anhydride-isobutylene copolymer, maleic anhydride-isobutyl vinyl ether copolymer And a maleic anhydride-acrylonitrile copolymer, a maleic anhydride-styrene copolymer and the like, and one or more of these can be used.

The polyfunctional isocyanate is not particularly limited, but is a compound having two or more isocyanate groups in one molecule, such as tolylene diisocyanate (also referred to as "TDI"), 4,4 '. -Diphenylmethane diisocyanate (also called "MDI"), hexamethylene diisocyanate, xylylene diisocyanate,
Isocyanate compounds such as meta-xylylene diisocyanate, 1,5-naphthalenedi isocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate; Sumidule N ( Bullet polyisocyanate compounds such as Sumitomo Bayer Urethane; Desmodur IL, HL (Bayer A.
G. FIG. Polyisocyanate compounds having an isocyanurate ring, such as Coronate EH (manufactured by Nippon Polyurethane Industry Co., Ltd.); And adduct polyisocyanate compounds. These can be used alone,
Two or more of them can be used in combination. Further, a block isocyanate may be used.

The epoxy compound is not particularly limited, but has at least two epoxy groups in the molecule. Examples thereof include (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, and polytetraethylene glycol. Methylene glycol diglycidyl ether, resorcin diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, diglycidyl adipate, diglycidyl orthophthalate, diglycidyl terephthalate, hydroquinone diglycidyl ether , Bisphenol S diglycidyl ether, glycerol diglycidyl ether, sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, Li glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether,
Diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanurate,
Glycerol triglycidyl ether, trimethylolpropane polyglycidyl ether and the like can be mentioned, and one or more of these can be used.

The oxazoline compound is not particularly restricted but includes, for example, 2-oxazoline, 2-methyl-2
-Oxazoline, 2-ethyl-2-oxazoline, 2-
Isopropyl-2-oxazoline, 2-butyl-2-oxazoline, 2-phenyl-2-oxazoline, 2,
2'-bis- (2-oxazoline), 2,2'-methylene-bis- (2-oxazoline), 2,2'-ethylene-bis- (2-oxazoline), 2,2'-trimethylene-bis- (2-oxazoline), 2,2′-tetramethylene-bis- (2-oxazoline), 2,2′-hexamethylene-bis- (2-oxazoline), 2,2′-
Octamethylene-bis- (2-oxazoline), 2,
2′-ethylene-bis- (4,4′-dimethyl-2-oxazoline), 2,2′-p-phenylene-bis- (2
-Oxazoline), 2,2'-m-phenylene-bis-
(2-oxazoline), 2,2'-m-phenylene-bis- (4,4'-dimethyl-2-oxazoline), bis- (oxazolinylcyclohexane) sulfide, bis- (2-oxazolinylnorbornane) Sulfides and the like can be mentioned, and one or more of these can be used. .

The amount of the chain extender used in the present invention is 0.001 to 10% by weight based on the polyalkylene glycol.
And more preferably 0.01 to 5% by weight. When the reaction ratio between the polyalkylene glycol and the chain extender is less than the lower limit of 0.001% by weight, the polyalkylene glycol cannot be sufficiently increased in molecular weight. If the amount is more than the upper limit of 10% by weight, unreacted chain extender increases, which is economically disadvantageous.

In the present invention, the reaction method between the polyalkylene glycol and the chain extender is not particularly limited.
The above-mentioned chain extender may be added to the polyalkylene glycol having a water content of 5000 ppm or less and reacted while stirring in a heated and molten state.

The reaction temperature may be a temperature at which the polyalkylene glycol and the chain extender can be melt-stirred, and is preferably 50 to 250 ° C., more preferably 100 to 250 ° C. in consideration of the thermal decomposition of the polyalkylene glycol. ~
200 ° C.

When a phosphoric ester and / or a phosphite is used as a chain extender, the internal pressure of the reactor is preferably reduced to 5 mmHg in order to efficiently remove the alcohol eliminated by transesterification. Less than,
More preferably, it is 1 mmHg or less. When using a polyfunctional acid anhydride or a polyfunctional isocyanate as a chain extender, the reaction can be performed at normal pressure.

The high molecular weight polyalkylene glycol thus obtained can be molded and used for various purposes.

[0025]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. The parts in the examples are parts by weight, and the number average molecular weight is the number average molecular weight in terms of polystyrene using a gel permeation chromatograph. The water content of the polyalkylene glycol was measured with a chloroform solution using a Karl Fischer moisture meter.

Example 1 A commercially available polyethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., number average molecular weight 300) was placed in a reaction vessel equipped with a stirrer, a vacuum line, and a heating jacket.
0, water content 1%), heated and melted at 150 ° C., deaerated, and stirred for 2 hours to obtain polyethylene glycol (1) having a water content of 1000 ppm and a number average molecular weight of 3000.

This polyethylene glycol (1) 100
And 1.14 parts of diphenyl phosphite were charged into a self-cleaning twin-screw mixer equipped with a vacuum line and a heating jacket, and stirred at 100 rpm under a reduced pressure of 1.8 to 3.7 mmHg in a nitrogen stream. And jacket temperature 1
By reacting at 50 ° C. for 3 hours, the number average molecular weight is 1
50,000 high molecular weight polyethylene glycols were obtained.

(Example 2) A water content of 1000 ppm and a number average molecular weight of 300 obtained by the same treatment as in Example 1
100 parts of polyethylene glycol (1) and 1.14 parts of diphenyl phosphite were charged into a reaction vessel equipped with a vacuum line and a heating jacket, and the jacket temperature was set to 150.
The reaction was carried out at a reduced pressure of 1 mmHg at a temperature of 3 ° C. for 3 hours to obtain a high molecular weight polyethylene glycol having a number average molecular weight of 60000.

Example 3 A commercially available polyethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., number average molecular weight 2,000) was placed in a reaction vessel equipped with a stirrer, a vacuum line, and a heating jacket.
0, water content 1%), heated and melted at 150 ° C., deaerated, and stirred for 2 hours to obtain polyethylene glycol (2) having a water content of 1000 ppm and a number average molecular weight of 20,000.

This polyethylene glycol (2) 100
Parts and 1.58 parts of pyromellitic dianhydride were charged into a reaction vessel equipped with a vacuum line and a heating jacket, and reacted at a jacket temperature of 140 ° C. and normal pressure for 30 minutes to obtain a high molecular weight polyethylene having a number average molecular weight of 100,000. Glycol was obtained.

Example 4 100 parts of polyethylene glycol (1) having a water content of 1000 ppm and a number average molecular weight of 3000, obtained by the same treatment as in Example 1, were placed in a reaction vessel equipped with a heating jacket, and hexamethylene was used. 7.8 parts of diisocyanate and 0.1 parts of dibutyltin dilaurate
Then, the mixture was reacted at an internal temperature of 130 ° C. and normal pressure for 15 minutes to obtain a high-molecular-weight polyethylene glycol having a number average molecular weight of 80,000.

(Example 5) A water content of 1000 ppm and a number average molecular weight of 300 obtained by the same treatment as in Example 1.
100 parts of polyethylene glycol (1), 1.14 parts of diphenyl phosphite, 3.9 parts of hexamethylene diisocyanate, and 0.05 parts of dibutyltin dilaurate.
And a reaction vessel equipped with a vacuum line and a heating jacket, and reacted at a jacket temperature of 150 ° C. under a reduced pressure of 1 mmHg for 1 hour to obtain a number average molecular weight of 70.
A high molecular weight polyethylene glycol of 000 was obtained.

Comparative Example 1 In a reaction vessel equipped with a vacuum line and a heating jacket, 100 parts of commercially available polyethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., number average molecular weight 3000, water content 1%) and diphenyl phosphite were added. After charging 1.14 parts and reacting at an internal temperature of 150 ° C. under a reduced pressure of 1 mmHg for 3 hours, the molecular weight of the product after the reaction did not increase to 20,000 or more.

[0034]

According to the present invention, a high molecular weight polyalkylene glycol can be efficiently produced in a short time.

The high-molecular-weight polyethylene glycol obtained in the present invention can be used in a film or sheet without causing a crosslinking reaction after the molecular weight is increased, and without causing a problem in the appearance of a molded article due to the crosslinking reaction. Since it can be easily molded into water, it can be effectively used for water-soluble packaging materials, daily necessities and the like.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-271635 (JP, A) JP-A-54-112999 (JP, A) JP-B-42-13021 (JP, B1) US Patent 5302255 (US , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 65/00-65/48 C08G 18/00-18/87

Claims (2)

(57) [Claims] 1. A polyalkylene glycol to be used when the polyalkylene glycol is increased in molecular weight with a chain extender.
It was degassed under heating and melting method for producing a high molecular weight polyalkylene glycols, characterized in that the water content of the polyalkylene glycol and 1000 ppm or less. Wherein said chain extender, contact (A) phosphoric acid ester
The method for producing a high-molecular-weight polyalkylene glycol according to claim 1, wherein the compound is one or more compounds selected from the group consisting of polyfunctional acid anhydrides.