Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2000-03-02
2002-01-22
Moore, Margaret G. (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S839000, C524S845000
Reexamination Certificate
active
06340726
ABSTRACT:
FIELD OF THE INVENTION
This application relates to silicone polymer diol emulsions. This application further relates to silicone blend condensation polymers and methods of making the same. Such condensation polymers may be prepared by introducing a silicone polymer emulsion into a condensation polymerization reaction to provide a condensation polymer/silicone polymer blend. The silicone polymer emulsions utilized in the preparation of the condensation polymers may comprise water, diol and, optionally cosolvents.
BACKGROUND
It is known to modify condensation polymers by blending the condensation polymer with another polymer in an extruder. For example, to improve the impact properties of a polyester, a low Tg elastomer is typically added to the polyester in a twin-screw extruder. Japan Kokai JP 02155944 describes compounds for molded articles comprising physical blends of saturated polyester with polystyrene polymers containing 1-100 phr glycidylamido-grafted olefin polymers of glycidyl methacrylate-graft olefin polymers. The size of the dispersed phase is critical in obtaining good properties. However, such extrusion processes are energy intensive, and often result in the reduction in the physical properties of the polymer, in particular the molecular weight, and require a blending step, which utilizes more resources and more time.
Typically, low Tg elastomers are used to impact modify the polyester. These low Tg elastomers are difficult to handle and often require that a second monomer, such as poly(methyl methacrylate) to be utilized as a “shell” surrounding the low Tg polymer “core” so that the low Tg polymer may be handled. The core-shell polymer is isolated, dried and then added to the polyester in an extruder. U.S. Pat. Nos. 5,652,306, 4,180,494 and 5,409,967 disclose compositions for impact modification of aromatic polyesters that involve blending an acrylic or polybutadiene/acrylic rubber powder with polylethylene terephthalate (PET). The acrylic rubber particles are prepared by typical core/shell emulsion polymerization and then harvested by spray drying the emulsion. The harvested rubber is then melt blended in an extruder to produce the impact modified PET.
Silicone rubber has also been utilized as a low Tg polymer for modifying polyesters. U.S. Pat. No. 5,594,059 discusses the melt mixing of silicone rubber powder into polyester and polycarbonate blends. These compositions are a physical blend of silicone rubber and polyester/polycarbonates. As noted, such melt mixing techniques are expensive and time consuming, thus, it would be beneficial to be able to combine silicone polymers with materials such as polyesters without the need for such mixing.
There exists a need for a process for producing a polymer blend by more economical methods. Such a need has been solved by the present invention, which can achieve such a blend in a polymerization reactor, wherein the physical properties of the condensation polymer are maintained or improved.
SUMMARY OF THE INVENTION
In one aspect, the invention provides a silicone polymer emulsion comprising:
a. a silicone polymer;
b. a surfactant; and
c. a liquid continuous phase comprising a diol, wherein the diol comprises from about 25 to about 100% by weight of the continuous phase.
In a further aspect, the invention provides a method of making a condensation polymer/silicone polymer blend comprising the steps of:
a. preparing a silicone polymer emulsion comprising a silicone polymer in a liquid continuous phase;
b. introducing the silicone polymer emulsion into a condensation polymerization reaction medium prior to or during the condensation polymerization reaction, wherein the condensation polymerization reaction medium comprises (1) a diacid, di-isocyanate; dialkyl carbonate, diaryl carbonate, dihalo carbonate or a mixture thereof, and wherein the continuous phase, the condensation polymerization reaction medium or both comprises a diol component; and
c. polymerizing the diol and component b(1), thereby forming a condensation polymer/silicone polymer blend.
In yet a further aspect, the invention provides a method of making a condensation polymer/silicone polymer blend comprising the steps of:
a. preparing a polymer colloid system comprising a silicone polymer dispersed in a liquid continuous phase;
b. introducing the polymer colloid system into a glycolysis reaction medium prior to or during the glycolysis reaction wherein the glycolysis reaction medium comprises a polyester, copolyester, polyesteramide, polycarbonate, or a mixture thereof, wherein the liquid continuous phase, the gylcolysis reaction medium, or both comprises a diol component; and
c. polymerizing the fully or partially glycolyzed polyester, copolyester, polyesteramide, polycarbonate or mixture thereof, thereby providing a condensation polymer/silicone polymer blend.
In yet a further embodiment, the invention provides a method of making a condensation polymer/silicone polymer blends comprising the steps of:
a. preparing a polymer colloid system comprising a silicone polymer and a liquid continuous phase;
b. introducing the polymer colloid system into a condensation polymer; and
c. extruding the polymer colloid system and the condensation polymer, thereby providing a condensation polymer/silicone polymer blend.
Additional advantages of the invention will be set forth in part in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the Examples included therein.
Before the present compositions of matter and methods are disclosed and described, it is to be understood that this invention is not limited to specific synthetic methods or to particular formulations, and, as such, may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.
In this specification and in the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings.
The singular forms a, an and the include plural referents unless the context clearly dictates otherwise.
Optional or optionally means that the subsequently described event or circumstances may or may not occur, and that the description included instances where said event or circumstance occurs and instances where it does not.
Silicone polymer emulsion is herein defined as a dispersion of polymeric particles in a continuous phase, the polymeric particles preferably having a size range of from about 0.1 to about 10 microns. The silicone polymers of the present invention preferably have a molecular weight of from about 5,000 to about 1,000,000 Daltons. The polymeric particles are preferably produced through emulsion polymerization processes. Alternatively, such emulsions may be prepared through direct emulsification e.g., mechanical emulsification processes.
Ranges are often expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value is another embodiment.
Diol is a synonym for glycol or dihydric alcohol. Polyol is a polyhydric alcohol containing three or more hydroxyl groups.
The abbreviation “nm” means nanometers. “Tg” means glass transition
Hale Wesley R.
Jones Allan Scott
Murray David Logan
Eastman Chemical Company
Graves, Jr. Esq. Bernard J.
Moore Margaret G.
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