Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From reactant having at least one -n=c=x group as well as...
Reexamination Certificate
2000-05-30
2002-06-25
Dawson, Robert (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From reactant having at least one -n=c=x group as well as...
C528S408000, C568S618000, C568S621000, C525S404000, C524S762000
Reexamination Certificate
active
06410676
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a method for producing a polyoxyalkylene polyol, and a method for producing derivatives thereof such as a polymer-dispersed polyol, isocyanate group-ended prepolymer, polyurethane and the like, by applying the above-described production method. More particularly, the present invention relates to a method for producing a polyoxyalkylene polyol in which a crude polyoxyalkylene polyol obtained by addition polymerization of an epoxide compound to an active hydrogen compound in the presence of a catalyst composed of a compound having a P═N bond is allowed to contact with a solid acid having specific form, and a method for producing derivatives thereof such as a polymer-dispersed polyol, isocyanate group-ended prepolymer, flexible polyurethane foam, polyurethane resin and the like, by applying the above-described production method.
BACKGROUND ART
Usually, a polyoxyalkylene polyol is produced at industrial scale by addition polymerization of an alkylene oxide to an active hydrogen compound in the presence of a potassium hydroxide (hereinafter, referred to as KOH) catalyst. That is, a KOH catalyst and an active hydrogen compound are dehydrated by heating under reduced pressure to prepare a polymerization initiator (potassium salt of an active hydrogen compound), then, the polymerization initiator is reacted with an alkylene oxide being supplied continuously until desired molecular weight is obtained under conditions of a reaction temperature of 105 to 150° C. and a maximum reaction pressure of 490 to 588 kPa to give a crude polyoxyalkylene polyol. Then, potassium in the crude polyoxyalkylene polyol is neutralized with an acid such as an inorganic acid and the like, dehydrated a and dried to precipitate a potassium salt which is subjected to a purification process such as filtration and the like, giving a polyoxyalkylene polyol.
However, it is known that, in the case of addition polymerization of propylene oxide which is most widely used as an alkylene oxide, a monool having an unsaturated group at the molecular end is by-produced together with an increase in the molecular weight of a polyoxyalkylene polyol.
Usually, the molecular weight of a monool corresponds to the total unsaturation degree (hereinafter, referred to as C═C) of a polyoxyalkylene polyol. Since this monool has a lower molecular weight as compared with that of a polyoxyalkylene polyol produced in the main reaction, the monool enlarges significantly the molecular weight distribution of the polyoxyalkylene polyol and reduces the average functionality. Therefore, a polyurethane resin obtained by using a polyoxyalkylene polyol having high monool content gives undesirable results such as an increase in hysteresis, a decrease in hardness, a lowering of curing property, an increase in compression set and the like irrespective of a physical state of the resin, that is, foam or elastomer.
Therefore, there have been conducted various studies to inhibit formation of the by-product monool and to improve productivity of the polyoxyalkylene polyol. For example, U.S. Pat. No. 3,829,505 and U.S. Pat. No. 4,472,560 suggest a method in which a double metal cyanide complex (hereinafter, referred to as DMC) is used as a catalyst for propylene oxide addition polymerization. DMC manifests excellent property as a polymerization catalyst of propylene oxide. However, when DMC is used as a catalyst and ethylene oxide is addition-polymerized as an alkylene oxide, it is necessary to once deactivate DMC by reaction with an oxidizer such as a gas containing oxygen, a peroxide, sulfuric acid and the like, to separate catalyst residue from a polyol, and further to conduct addition polymerization of ethylene oxide using an alkaline metal hydroxide such as KOH, an alkaline metal alkoxide and the like (U.S. Pat. No. 5,235,114), leading to complicated operations.
Japanese Laid-Open Patent Publication (JP-A) No. Hei-7-278289 discloses a polyoxyalkylene polyol having a hydroxyl value (hereinafter, abbreviated as OHV) of 10 to 35 mg KOH/g, a monool maximum content of 15 mol %, and further, a head-to-tail (hereinafter, simply expressed as H—T) bond minimum selectivity due to propylene oxide addition polymerization of 96% obtained by using cesium hydroxide and the like as a catalyst. This polyoxyalkylene polyol is a polyoxyalkylene polyol which has low viscosity even if the monool content is reduced and gives a flexible polyurethane foam having an excellent mechanical quality, and excellent properties. However, it requires a fairly long reaction time to produce, for example, a polyoxyalkylene polyol of high molecular weight having an OHV of 15 mg KOH/g and a low monool content of 15 mol % or less using cesium hydroxide as a catalyst, therefore, when productivity of the polyol is taken into consideration, this catalyst is not necessarily satisfactory.
On the other hand, as a catalyst for producing a polyoxyalkylene polyol containing no metal, phosphazene compounds have been suggested (EP 0763555, Macromol. Rapid Commun., Vol. 17, pp. 143 to 148, 1996 and Macromol. Symp., Vol. 107, pp. 331 to 340, 1996). When these phosphazene compounds are used as a catalyst for producing a polyoxyalkylene polyol, advantages wherein that productivity of the polyoxyalkylene polyol increases steeply in addition to low by-production ratio of a monool exist.
The present inventors have suggested a polyoxyalkylene polyol in which C═C content is low, H—T bond selectivity is high and the molecular weight distribution of a polyol which is a main reaction component is sharp using as a catalyst a novel phosphazenium compound, and a method for producing this polyoxyalkylene polyol in a patent application relating to International Publication WO 98/54241 (EP 0916686A1). When a phosphazenium compound is used as a catalyst for producing a polyoxyalkylene polyol, even if production of a polyol is conducted using propylene oxide as a monomer, there are advantages in that the by-production ratio of a monool is low and the productivity of a polyoxyalkylene polyol increases steeply.
On the other hand, phosphine oxide compounds are publicly a known in addition to phosphazene compounds and phosphazenium compounds (Journal of General Chemistry of the USSR, Vol. 55, p. 1453 (1985)). In this literature, a method for producing a phosphine oxide compound, and a reaction example using methyl iodide are described. However, there is no disclosure regarding use of a phosphine oxide compound as a catalyst for producing a polyol.
The present inventors have suggested a method for purifying a crude polyoxyalkylene polyol produced by using a phosphazenium compound as a catalyst in the above-described patent application relating to International Publication WO 98/54241 (EP 0916686A1) (methods e to h on page 11, line 21 to page 12, line 17). The method e in this purification method is an excellent method for purifying a polyol which can control the catalyst-remaining amount to 150 ppm or less by synergism of an acid, water and adsorbent in specific amounts. The method f is a method in which an organic solvent inactive with a polyol is used together in specific amounts in the method e. In both of the methods e and f, an adsorbent in specific amounts is used. However, in these methods, a remaining catalyst is removed using an adsorbent after neutralization treatment with an acid as pre-treatment, and the process is slightly longer.
In both of the methods g and h which are other methods using no adsorbent, water or an organic solvent in large amounts is used. Therefore, after the purification treatment, there is required a process for removing water or an organic solvent from a polyoxyalkylene polyol. Depending on the molecular structure of a polyoxyalkylene polyol, the yield of a polyol may sometimes decrease since a part of the polyol is dissolved in water due to contact operation with a large amount of water. Any of these methods include a longer process, and is not necessarily satisfactory.
As described above, compounds having a P═N bond such as
Hara Yasunori
Isobe Masahiro
Izukawa Tsukuru
Kunihiro Tamotsu
Matsufuji Mikio
Burns Doane Swecker & Mathis
Dawson Robert
Mitsui chemicals, Inc.
Peng Kuo Liang
LandOfFree
Method for producing polyoxyalkylene polyol and derivatives... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for producing polyoxyalkylene polyol and derivatives..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for producing polyoxyalkylene polyol and derivatives... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2895114