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
2000-11-17
2003-01-07
Short, Patricia A. (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...
C528S052000, C528S065000, C528S066000, C528S076000, C528S081000
Reexamination Certificate
active
06503997
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a polyurethane type/polyurethane urea type resin obtained by reacting a novel isocyanate group-terminated polyurethane prepolymer with a chain extender such as an amine type chain extender and a method for producing the same
BACKGROUND ART
It is known to produce a polyurethane type/polyurethane urea type resin for an artificial leather or an elastic yarn by reacting a, polyisocyanate compound with a high molecular amount polyol such as polyoxytetramethylene glycol (hereinafter referred to as “PTMG”) and a polyester polyol (hereinafter referred to as “PES”) to prepare an isocyanate group-terminated polyurethane prepolymer, preparing a resin solution by reacting the prepolymer with a chain extender in a solvent and then subjecting the resin solution to processing treatment (solution polymerization method).
The polyurethane type/polyurethane urea type resin obtained by the above solution polymerization method has properties of a high elasticity, a high elongation, a high durability and the like, and is therefore usable as an elastic fiber for a stretch fabric material.
On the other hand, since this is poor in breaking strength, it has: been proposed to use a secondary hydroxyl group-terminated polyol such as polyoxypropylene polyol which has not been used alone, in combination with PTMG and PES for a polyurethane type/polyurethane urea type elastic yarn (WO98-16568). This international patent publication discloses to obtain an isocyanate group-terminated polyurethane prepolymer by reacting a polyisocyanate compound with a mixture of polyoxypropylene polyol and PTMG in view of physical properties, moldability and economic properties of a product.
However, according to the method of using a mixture of polyols disclosed in the above international patent publication, PTMG having a primary hydroxyl group terminal is first reacted with a polyisocyanate compound due to difference in reactivity of a hydroxyl group in polyol, and as this result, physical strength and heat resistance of the resin thus obtained are lowered.
Further, since polyoxypropylene polyol has a secondary hydroxyl group terminal, a reaction speed in the preparation of a prepolymer is low and it takes a very long time to prepare the prepolymer.
Also, for example, a major part of polyoxypropylene/oxyethylene polyol having at most 30 wt % of an oxyethylene group at the terminal is a primary hydroxyl group terminal, but a small amount of a secondary hydroxyl group terminal is also present, and therefore the same problem as mentioned above is raised even when using such a polyol..
Thus, the present invention provides a polyurethane type/polyurethane urea type resin and a method for producing the same, the strength and heat resistance of which can be greatly improved and the production time of which can be reduced, even when using polyoxypropylene polyol in combination with PTMG or PES.
DISCLOSURE OF THE INVENTION
In order to achieve the above object, the present invention provides a polyurethane type/polyurethane urea type resin obtained by reacting an isocyanate group-terminated polyurethane prepolymer (A) obtained by reaction of a high molecular weight active hydrogen compound and a polyisocyanate compound, with a chain extender (B), wherein said isocyanate group-terminated polyurethane prepolymer (A) is an isocyanate group-terminated polyurethane prepolymer obtained by reacting the following polyol (1) with a polyisocyanate compound under such a condition that an isocyanate group is excessively present and further by reacting the following polyol (2) with a polyisocyanate compound under such a condition that an isocyanate group is excessively present;
Polyol (1): a polyoxyalkylene polyol having a hydroxyl group value of at most 70, a total unsaturation degree of at most 0.07 meq/g and an oxypropylene group content of at least 70 wt %, and
Polyol (2): a polyol selected from the group consisting of polyoxytetramethylene glycol (PTMG), polyester polyol, polycaprolactone polyol and polycarbonate polyol.
Also, the present invention provides a method for producing a polyurethane type/polyurethane urea type resin by reacting an isocyanate group-terminated polyurethane prepolymer (A) obtained by reaction of a high molecular weight active hydrogen compound and a polyisocyanate compound, with a chain extender (B), wherein the isocyanate group-terminated polyurethane prepolymer (A) is an isocyanate group-terminated polyurethane prepolymer obtained by reacting a polyisocyanate compound with said polyol (1) in the presence of an excess amount of an isocyanate group and further reacting with said polyol (2) in the presence of an excess amount of an isocyanate group.
Further, the present invention provides a method for producing a polyurethane type/polyurethane urea type resin by reacting an isocyanate group-terminated polyurethane prepolymer (A) obtained by reaction of a high molecular weight active hydrogen compound and a polyisocyanate compound with a chain extender (B) in a solvent and removing the solvent, wherein the isocyanate group-terminated polyurethane prepolymer (A) is an isocyanate group-terminated polyurethane prepolymer obtained by reacting a polyisocyanate compound with said polyol (1) in the presence of an excess amount of an isocyanate group and further reacting with said polyol (2) in the presence of an excess amount of an isocyanate group.
According to the present invention, by using the isocyanate group-terminated polyurethane prepolymer obtained by reacting a polyisocyanate compound with said polyol (1) and further reacting with said polyol (2), the above reaction can be completed in a short time and a polyurethane type/polyurethane urea type resin excellent in strength and heat resistance can be obtained. The polyurethane type/polyurethane urea type resin thus obtained is suitable as a material for an artificial leather, an elastic yarn and the like.
BEST MODE FOR CARRYING OUT THE INVENTION
The “polyurethane type/polyurethane urea type resin” of the present invention indicates a “polyurethane urea resin” prepared by using mainly a diamine compound as a chain extender and a “polyurethane resin” prepared by using mainly a polyol compound as a chain extender.
In the present invention polyol (1) is a polyoxyalkylene polyol having a hydroxyl group value of at most 70, a total unsaturation degree of at most 0.07 meq/g and an oxypropylen group content of at least 70 wt %. Polyol (1) may be a mixture. Also, if necessary, it may be used in combination with other polyoxyalkylene polyol having a hydroxyl group value, a total unsaturation degree and an oxypropylene group content outside the above-mentioned ranges. In such a case, it is necessary that an average hydroxyl group value, an average total unsaturation degree and an average oxypropylene content are within the above-mentioned respective ranges.
The hydroxyl group value of polyol (1) is preferably from 5 to 60. If the hydroxyl group value exceeds 70, a satisfactory flexibility can not be obtained, and if the hydroxyl group value is less than 5, a satisfactory strength can not be obtained.
Also, the total unsaturation degree of polyol (1) is preferably at most 0.04 meq/g and is preferably at most 0.02 meq/g particularly when the hydroxyl group value of polyol (1) is relatively high (e.g. hydroxyl group value=28 to 70). If the total unsaturation degree is higher than the above-mentioned value, it is not preferably since a residual tack is increased and a strength is lowered.
Also, the oxypropylene group content is preferably at least 85 wt %.
The above-mentioned polyol (1) can be obtained by reacting propylene oxide or propylene oxide and other monoepoxide with a polyfunctional initiator in the presence of a catalyst such as diethyl zinc, iron chloride, metal porphyrin, double metal cyanide complex or the like.
In the present invention, it is particularly preferable to use double metal cyanide complex. Among them, a complex comprising zinc hexacyanocobaltate as the main component is preferable, and its ether and
Kashiwame Josho
Saito Joichi
Asahi Glass Company Limited
Short Patricia A.
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