Photocurable compositions containing reactive polysiloxane particles

#1. Field of the Invention

#The invention relates to photocurable compositions, more particularly to photocurable compositions for stereolithography.

#2. Related Art

#The general procedure used for preparing 3-D objects with SL equipment is as follows. The photocurable composition was placed in a 300-700 ml plastic container or in a vat designed for use with the stereolithography machines. The specific container depends on the size of the desired 3-D object. The photocurable composition was poured into the container within the machine at about 30° C. The surface of the composition, in its entirety or a predetermined pattern, was irradiated with a UV/VIS light source so that a layer of a desired thickness cured and solidified in the irradiated area. A new layer of the photocurable composition was formed on the solidified layer. The new layer was likewise irradiated over the entire surface or in a predetermined pattern. The newly solidified layer adhered to the underlying solidified layer. Repeating the layer formation step and the irradiation step produced a green model of multiple solidified layers.

#The green model was then rinsed in tripropylene glycol monomethyl ether (“TPM”). The green model was then rinsed with water and dried with compressed air. The dried green model was then postcured with UV radiation in a postcure apparatus (“PCA”) for about 60-90 minutes.

#Stereolithography equipment typically allows for setting various operational parameters. Examples thereof appear in Tables II and III below. The parameters are well known to a person of skill in the art of stereolithography and may be adjusted as needed depending on various factors, including the specific photocurable composition and the geometry of the desired 3-D object.