Abstract:
Disclosed is an organocyclosiloxane which comprises a compound having the following formula: ##STR1## wherein R 1 , R 2  and R 3 , which may be the same or different, represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms; Y represents ##STR2## m is an integer of 3 to 5 and n is an integer of 1 to m.

Description:
The present application claims priority of Japanese patent application Ser. No. 84/201179 filed Sept. 26, 1984. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to a novel and useful organocyclosiloxane having an ethylidene norbornyl group. 
     In general, in an addition type silicone elastomer which has widely been used, cross-linking thereof has been carried out through a vinyl group in most cases. Accordingly, a siloxane having a vinyl group is well known but a siloxane which has a condensed cyclic type hydrocarbyl group having an aliphatic unsaturated side chain has not yet been known. 
     SUMMARY OF THE INVENTION 
     The present inventors have carried out extensive studies concerning a siloxane which as a condensed cyclic type hydrocarbyl group having an aliphatic unsaturated side chain to accomplish the present invention. 
     That is, the organocyclosiloxane of the present invention comprises a compound having the following formula: ##STR3## wherein R 1 , R 2  and R 3 , which may be the same or different, represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms; Y represents ##STR4## m is an integer of 3 to 5 and n is an integer of 1 to m. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 illustrates an infrared absorption spectrum of the mixture obtained in Example 1. 
    
    
     DESCRIPTION OF THE INVENTION 
     In the above general formula, examples of the R 1 , and R 2  and R 3  may include, in addition to a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a phenyl group and the like. Among these, the methyl group is preferred since it is easy to obtain a starting intermediate compound and ease of synthesis. 
     While m can be an integer of 3 to 5, it is preferred that m is 4 for ease of obtaining a starting intermediate compound and ease of synthesis. 
     Further, n is an integer of 1 to m, particularly preferred is an integer of 1 to 4. 
     In order to have at least one of characteristic groups of: ##STR5## in the organocyclosiloxane of the present invention, n cannot be 0. 
     Exemplary compounds of the organocyclosiloxane of the present invention are illustrated below, wherein Y has the same meaning as defined above. ##STR6## 
     These organocyclosiloxane can be synthesized by, for example, reacting an organohydrogencyclosiloxane represented by the formula: ##STR7## with 5-ethylidenebicyclo(2,2,1)hept-2-ene represented by the formula: ##STR8## as starting materials. 
     The reaction can be carried out by using an equimolar or more, preferably, 1.0 to 2.0 moles of the 5-ethylidenebicyclo(2,2,1)hept-2-ene (II) based on the molar number of Si-H bonding of the organohydrogen cyclosiloxane (I), and carrying out the addition reaction in the presence of a platinum compound such as chloroplatinic acid, etc., as a catalyst to obtain the desired product. The conditions of the addition reaction depend on the final product to be obtained, but generally the reactants are heated at 30° to 180° C. for 5 to 50 hours. The final product can generally be obtained as a mixture of two compounds since two kinds of addition reactions to the compound (II) have been presented, and the product can be used as it is or after separation thereof by a known method for producing an elastomer and the like. 
     EXAMPLES 
     In the following, the present invention will be explained by referring to the Examples. In the Examples, all parts are by weight. 
     EXAMPLE 1 
     In a flask equipped with a dropping funnel were charged 180 parts of 5-ethylidenebicyclo(2,2,1)hept-2-ene and 0.04 part of chloroplatinic acid as a catalyst and the mixture was heated to 130° C. Then, 282 parts of heptamethylcyclotetrasiloxane was gradually added dropwise from the dropping funnel while keeping the temperature of the mixture at 130° C. and the addition reaction was carried out for 10 hours. Under reduced pressure (10 mmHg), stripping was carried out at 130° C. to remove the unreacted materials and then distillation was carried out to obtain 300 parts (Yield: 75%) of a mixture of the compounds (a) and (b) shown below in a ratio of 1.2:1. 
     Compound (a): ##STR9## wherein ##STR10## 
     Compound (b): ##STR11## wherein 
     
         ______________________________________ ##STR12## 
    
     
         ______________________________________Boiling point:      118° C./3.5 mmHgRefractive index (n.sub.D.sup.25):               1.448Specific gravity:   0.999Molecular weight:   402(by gas-mass spectrum analysis)______________________________________Elemental analysis:               Calculated      Observed (as C.sub.16 H.sub.34 O.sub.4 Si.sub.4)______________________________________C          48.1     47.8H           8.5      8.4O          15.6     15.9Si         27.8     27.9______________________________________ 
    
     Infrared absorption spectrum: shown in FIG. 1. 
     EXAMPLE 2 
     In a flask equipped with a dropping funnel were charged 300 parts of 5-ethylidenebicyclo(2,2,1)hept-2-ene and 0.06 part of chloroplatinic acid as a catalyst and the mixture was heated to 130° C. Then, 268 parts of hexamethylcyclotetrasiloxane was gradually added dropwise from the dropping funnel while keeping the temperature of the mixture at 130° C. and the addition reaction was carried out for 15 hours. Under reduced pressure (10 mmHg), stripping was carried out at 130° C. to remove the unreacted materials and then distillation was carried out to obtain 355 parts (Yield: 70%) of a mixture of the compounds (c) and (d) shown below in a ratio of 1:1. 
     Compound (c): ##STR13## wherein ##STR14## 
     Compound (d): ##STR15## wherein 
     
         ______________________________________ ##STR16## 
    
     
         ______________________________________Boiling point:     180 to 190° C./4 mmHgRefractive index (n.sub.D.sup.25):              1.474Specific gravity:  1.026Molecular weight:  508(by gas-mass spectrum analysis)______________________________________Elemental analysis:               Calculated      Observed (as C.sub.24 H.sub.44 O.sub.4 Si.sub.4)______________________________________C          57.0     56.7H           8.8      8.7O          12.4     12.6Si         21.8     22.0______________________________________ 
    
     EXAMPLE 3 
     The same procedures as in Example 1 were carried out except that heptamethylcyclotetrasiloxane in Example 1 was replaced with 208 parts of pentamethylcyclotrisiloxane to obtain 226 parts (Yield: 69%) of a mixture of the compounds (e) and (f) shown below in a ratio of 1.1:1. 
     Compound (e): ##STR17## wherein ##STR18## 
     Compound (f): ##STR19## wherein 
     
         ______________________________________ ##STR20## 
    
     
         ______________________________________Boiling point:     95 to 105° C./5 mmHgMolecular weight:  328(by gas-mass spectrum analysis)______________________________________Elemental analysis:               Calculated      Observed (as C.sub.14 H.sub.28 O.sub.3 Si.sub.3)______________________________________C          51.0     51.2H           8.5      8.6O          14.9     12.6Si         25.6     25.6______________________________________ 
    
     EXAMPLE 4 
     The same procedures as in Example 1 were carried out except that heptamethylcyclotetrasiloxane in Example 1 was replaced with 356 parts of nonamethylcyclopentasiloxane to obtain 309 parts (Yield: 65%) of a mixture of the compounds (g) and (h) shown below in a ratio of 1.1:1. 
     Compound (g): ##STR21## wherein ##STR22## 
     Compound (h): ##STR23## wherein 
     
         ______________________________________ ##STR24## 
    
     
         ______________________________________Boiling point:     160 to 180° C./5 mmHgMolecular weight:  476(by gas-mass spectrum analysis)______________________________________Elemental analysis:               Calculated      Observed (as C.sub.18 H.sub.40 O.sub.5 Si.sub.5)______________________________________C          45.8     45.4H           8.5      8.4O          16.5     16.8Si         29.2     29.4______________________________________ 
    
     The compound of the present invention can be used, by utilizing the double bond being contained therein, as a cross-linking agent of polydiorganosiloxane which has been used as a main starting material of a silicone elastomer, and thus can be widely applied to the production of an elastomer.