Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
1999-12-20
2002-11-26
Szekely, Peter (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C008S590000, C524S102000, C524S119000, C524S120000, C525S123000, C525S125000, C525S127000, C526S263000, C526S265000, C546S188000, C546S190000
Reexamination Certificate
active
06486238
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a hindered amine compound, a resin composition comprising a hindered amine compound which achieves stabilizing effects (resistance to NO
x
, light stabilization, etc.) even after various processing processes, a resin composition comprising such a hindered amine compound which is sufficiently stabilized even after various processing processes, a polyurethane resin composition and fiber comprising such a hindered amine compound which is sufficiently stabilized even after various processing processes, and a method for the preparation of such a polyurethane fiber.
Furthermore, the present invention relates to a polyurethane resin composition and fiber which is stabilized against discoloration caused with NO
x
, and a method for the preparation of such a polyurethane fiber.
In addition, the present invention relates to a stretch fabric or knit comprising a polyurethane fiber and a non-stretch fiber such as a polyester fiber, a polyamide fiber, a cellulose fiber, etc.
2. Prior Art
Polyalkyl-substituted piperidine derivatives are called hindered amine compounds, and widely used as stabilizers of various resins since they have high stabilizing effects on resin materials.
Hindered amine compounds are usually used to suppress the degradation caused by light (UV rays). Hindered amine compounds of various structures are widely used depending on the kinds of resins to be stabilized, purposes, applications, etc.
Polyurethane resins are more easily deteriorated by various factors than other resins, and it is essential for polyurethane resins to compound stabilizers. Among the applications of polyurethane resin compositions, a polyurethane fiber particularly deteriorates since it has a large surface area per a unit weight.
Among the causes for the deterioration of polyurethane, even a slight amount of nitrogen oxides (NO
x
) discolor the polyurethane. Thus, it is highly desired to develop an effective stabilizer against NO
x
. Among others, hindered amine compounds have a high effect to suppress the discoloration of polyurethane with NO
x
, and thus various types of hindered amine compounds have been developed.
However, even polyurethane products which are stabilized by the compounding of hindered amine compounds often lose the stabilizing effects of the hindered amine compounds after secondary processing. One example of such a case is dyeing of polyurethane fibers. Fibers can be dyed by various methods depending on the kinds of fibers and applications of dyed fibers. In particular, fibers are often treated in an acidic aqueous solution. Hindered amine compounds form salts with acids in the acidic aqueous solution, since they are basic compounds. Thus, it is one reason why the stabilizing effects of the hindered amine compounds are lost that the hindered amine compounds form water-soluble salts and liberate from the fibers. Such a phenomenon is remarkable with low molecular weight hindered amine compounds, although high molecular weight hindered amine compounds having a molecular weight of several thousand to several ten thousand may encounter the same phenomenon. Therefore, the increase of the number of hindered amino groups in a molecule to improve the stabilizing effects lead to the easy liberation of the hindered amine compound by the treatment in the acidic solution. That is, the concentration of the hindered amino groups in a molecule has a close relationship with the liberation of a hindered amine compound from fibers, and the prevention of the liberation of hindered amine compounds is incompatible with the high stabilizing effects.
To ultimately prevent the liberation of hindered amine compounds, many literatures propose the reaction of the hindered amine compounds with polymers constituting resins. For example, the reaction of hindered amine compounds with polyurethane is disclosed in JP-A-53-1294, JP-A-53-39395, JP-A-5-155977, etc. However, when hindered amine compounds are reacted with resin polymers as disclosed in JP-A-53-1294 and JP-A-53-39395,the physical properties of the resins more or less deteriorate in comparison with unreacted resins. For example, when hindered amino groups are introduced at polymer chain ends using a hindered amine compound as a chain terminating agent, the increase of the number of terminal groups derived from the hindered amine compound to improve the stabilizing effects inevitably lead to the decrease of the molecular weight of the polymer. Accordingly, the improvement of the stabilizing effects by the increase of the number of terminal groups derived from hindered amine compounds is essentially incompatible with the improvement of physical properties by the increase of the molecular weight. Thus, it is impossible to increase both the physical properties and the stabilizing effects.
When a compound having a hindered amino group is incorporated as a side chain in a polymer chain, the molecular weight of the polymer is not influenced by the amount of the incorporated hindered amine compound, but the synthesis of the hindered amine compound and the polymerization of the polymer are complicated.
Even if polymers having hindered amino groups as side chains are prepared, the presence of bulky groups such as hindered amino groups in side chains has influences on the interaction of the polymer molecules and in turn on the physical properties of the polymers.
Many proposals have been made on the reaction of hindered amine compounds with polymers constituting resins other than polyurethane. For example, JP-A-5-262870, JP-A-6-207142, JP-A-6-240220 and JP-A-6-264029 disclose stabilized resins which are obtained by copolymerizing a polymerizable hindered amine monomeric compound having a carbon-carbon double bond with a polymerizable monomer constituting the resins. The polymerizable hindered amine monomeric compounds which are proposed in these Japanese patent applications are relatively easily copolymerized with the monomer constituting the resins, but the kinds of the resins to be copolymerized are limited to those of vinyl monomers.
Many proposals have been made on the use of copolymers of polymerizable hindered amine monomeric compounds and other polymerizable monomers as stabilizers of resins (see, for example, JP-A-5-112725, JP-A-9-3133, JP-A-10-46141, etc.)
These proposals can prevent the liberation of the hindered amine compounds by heat, or with neutral water or hot water. However, these proposals are not intended to prevent the liberation of the hindered amine compounds by the treatment with acids. Thus, they have the same drawbacks as those for the above high molecular weight hindered amine compounds.
JP-A-10-46141 discloses a polymer or a copolymer of a polymerizable hindered amine monomeric compound as a stabilizer which suppresses the yellowing of clothes during storage. However, the disclosed invention does not shape a compound as a product after compounding a hindered amine compound in a resin. Rather, the hindered amine compound is attached to shaped products such as finished clothes by post-processing. This process can stabilize the finished products, but the stability of intermediate products which are being processed prior to finishing cannot be improved. In particular, in the case of clothes, such a drawback is not negligible, since the processing from fibers to the finished products often takes a long time.
In the case of resins such as polyurethane which are particularly easily degraded, the resins themselves should have stability. Thus, stabilizers are compounded even in primary products prior to final products, and they should not lose stabilizing properties in the post-processing processes such as secondary processing.
Polyurethane is prepared from a polyisocyanate, a polymer diol having a relatively low molecular weight and a polyfunctional active hydrogen compound having a low molecular weight, and used in awide varietyof applications such as foams, elastomers, paints, synthetic leather, fibers, etc. because it has good mechanical properties and it
Ishimaru Futoshi
Kitamura Kota
Matsukawa Genei
Oshimo Chihiro
Kenyon & Kenyon
Szekely Peter
Toyo Boseki Kabushiki Kaisha
LandOfFree
Hindered amine compound, resin composition, polyurethane... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hindered amine compound, resin composition, polyurethane..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hindered amine compound, resin composition, polyurethane... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2966575