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
2000-07-14
2002-07-23
Dawson, Robert (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...
C524S237000, C524S266000, C524S284000, C524S356000, C524S379000, C524S424000, C524S427000, C524S434000, C524S435000, C524S439000, C524S440000, C524S714000, C524S765000, C524S773000, C524S796000, C524S779000, C524S860000, C528S015000, C528S025000, C528S034000, C528S035000, C528S043000, C525S474000, C525S475000, C525S477000, C525S478000, C525S479000
Reexamination Certificate
active
06423772
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an organosilicon material with ladderlike or tube-like structure and the method for producing the same, particularly the present invention relates to an organo-bridged ladderlike polysiloxane, tube-like organosilicon polymers, complexes thereof and the method for producing the same.
BACKGROUND ART
Polysiloxanes having a ladderlike structure have been widely used as the parts of electronic instruments, protection layer and interlayer insulation materials for semiconductors, pellicle materials, paint materials and the like, since they have excellent mechanical properties, and are excellent in heat resistance and electrical insulation.
Brown, J. F. (J. Am. Chem. Soc., 1960, 82, 6194) reported polyphenylsilsesquioxane with ladderlike structure. Japanese Patent No. 25061/1985(JP-B-60-25061), No. 36983/1989 (JP-B-1-36983) and No. 274056/1991(JP-A-3-274056) disclosed a photosensitive silicon resin composite comprising a ladderlike polysiloxane having an alkyl group, a phenyl group, a vinyl group, an allyl group and the like. Japanese Patent laid-open No.105881/1990 (JP-A-2-105991) disclosed a composite for forming a film comprising a hydroxy-terminated ladderlike polysiloxane having an alkyl group or a phenyl group and having a number-average molecular weight of 2000 to 5000.
However, it is difficult to obtain a high molecular weight polysiloxane with a ladderlike skeleton by using the methods described in the above publications. As is disclosed in the above applications, with the growing of the molecular weight of the ladderlike polysiloxane, the ladderlike skeleton in the polysiloxane tends to break and branch, resulting insolubility in organic solvents.
Especially, in the methods of above publications, trichlorosilanes having an alkyl group, an aralkyl group, or a phenyl group, which are unreactive or inert to hydrolysis(e.g., methyltricholorosilane and phenyltrichlorosilane) are used.
Chinese patent No. CN 94 1005071 disclosed highly regulated ladderlike hydrogen polysilsesquioxanes and copolymers and their preparation. In addition, there have been reported a highly regulated ladderlike reactive vinyl- or allyl-polysilsesquioxanes (React. Polym., 1999, 39, 1). Japanese Patent No. JP 08188649 disclosed highly regulated ladderlike polysilsesqioxanes and copolymers containing reactive groups and their preparation. They were synthesized via pre-coupling and stepwise hydrolysis, condensation by using organosilicon monomers containing reactive groups, such as trichlorosilane, vinyltrichlorosilane, allyltrichlorosilane, alkoxytrichlorosilane and the like as starting materials, and employing &agr;,&ohgr;-diamine as the coupling reagent. They have the following structure.
wherein R and R′ can be the same or different, and are selected from the family consisting of hydrogen, alkyl, alkoxyl, aryl such as phenyl and biphenyl, and alkenyl such as vinyl, allyl.
As described in the above-mentioned Chinese patent No. CN 941005071 and Japanese patent No. JP 08188649, the highly regulated ladderlike polysilsesquioxanes prepared via precoupling with &agr;,&ohgr;-diamine as coupling agent, hydrolysis and polycondensation have a high solubility and excellent film-forming ability, moreover, the gelification accompanied with growing molecular weight of the polymer as described in the earlier applications can be inhibited.
Especially, in the method described above, trichlorosilanes having reactive groups, such as hydrogen, vinyl and allyl, alkoxy groups etc can be used, because the reaction conditions are very mild. The resulted ladderlike polymers have reactive side chains, which can be used to produce different functional derivatives. The ladderlike polysiloxane possesses cis-isotactic configuration (Materials Science & Engineering, C 10, 1999, 13-18).
In the methods described in the above-mentioned Chinese patent No. CN 941005071 and Japanese patent No. JP 08188649, the first step is preamminolysis of trichlorosilane with &agr;,&ohgr;)-diamine to obtain an intermediate represented by the following formula(II):
wherein X represents a halogen atom (Cl, Br, I), Y represents a diamine residue. R is hydrogen, alkyl, alkenyl, aryl or other substituting groups. During hydrolyis and polycondensation the bridged diamine residue is gradually removed. That means the diamine residue exists in the intermediate compound only plays a role of temporary bridge.
According to the method as mentioned above, highly regulated ladderlike polysiloxane comprises a fixed Si—O—Si bridge in the ladder skeleton. So the dimension and affinity of ladder rung are limited.
Known tube-like polymers includes, for example, those reported by S. Lijima in 1991(Nature, 1991, 354, 56), in which the preparation and structure of nano-scale carbon tubes having poor solubility in organic solvent is described. In 1995, H. Nakamura et al reported a tube-like polymer prepared by using siloxane gel as starting material. However the polymer is neither soluble nor meltable. In 1993, A. Harada et al reported the formation of tube-like organic polymers by using naturally occuring cyclodextrins as the starting materials (Nature, 1993, 364, 576). Because the dimension and the shape of the cyclodextrin unit are fixed, the diameter and chemical affinity of the tube-like polymers are also fixed and difficult to control. For the above reasons, the applications of these tube-like polymers are limited.
There have been reported a supermolecular complex based on tube-like cyclodextrins as host molecule (Nature, 1993, 364, 76). In such supermolecular complex, the pore diameter of the tube and chemical affinity of the cavity can not be readily adjusted, therefore, the guest molecules to be entrapped inside the tube are limited. Entrapment of metal ions or metal oxide molecules inside a nano-scale carbon tube to form the supermolecular complex has also been reported (Chem. Commun., 1995, 1335). However the preparation involves complicated steps and severe reaction conditions. In addition, the selectivity of entrapment was very poor. Further, entrapment of polyaniline inside the tube of V
2
O
5
gel to form supermolecular complex has been reported (J. Am. Chem. Soc., 1989, 111, 4319). This complex showed electrical conductivity. However, since this supermolecular complex forms a cross-linked system, it is, neither soluble nor meltable, thus can not be reprocessed. In addition, the selectivity of entrapment was very poor too.
Chinese patent No. CN 9712236.9 (1997, 1) disclosed “tube-like organosilicon polymer and a method for producing the same”. The tube-like organosilicon polymer can be prepared in (1+1) mode or (2+2) mode of tubing reaction. The (1+1) mode means that a coupling reaction of one kind of cis-isotactic reactive ladderlike polysilsesquioxane with another kind of cis-isotactic reactive ladderlike polysilsesquioxane. The (2+2) mode means that two parts of one kind of cis-isotactic reactive ladderlike polysilsesquioxane with two parts of low molar mass coupling agents. Because the tube-like polymer is resulted from the above-mentioned ladderlike polysiloxane having fixed Si—O—Si bridge, so the dimension, shape and chemical affinity of the tube-like organosilicon polymer are also limited. And also the guest molecules that can be entrapped inside the tube are limited.
SUMMARY OF THE INVENTION
The present invention is directed to solving the problems of the limited dimension and chemical affinity associated with the above-mentioned fixed Si—O—Si bridged ladderlike polysilsesquioxanes and tube-like polymers derived therefrom.
It is an object of the present invention to provide an organo-bridged ladderlike polysiloxane, which is characterized by:
(1) having an adjustable organo-bridged ladder rung which can play a templating role, namely, the length of the ladder rung varies in the range of 5-50 Å, and its chemical affinity can be adjusted;
(2) having terminal groups that can play a prefixation role such as hydroxy, carboxylic, amino amid and the like;
(3) having a cis-
Liu Chunqing
Tang Huadong
Xie Ping
Zhang Rongben
Dawson Robert
Institute of Chemistry, Chinese Academy of Sciences
Knobbe Martens Olson & Bear LLP
Robertson Jeffrey B.
LandOfFree
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