Additive manufacturing method for producing a silicone elastomer article

An additive manufacturing method for producing a silicone elastomer article, said method comprising the following steps:

• i) using a photocrosslinkable silicone composition X and an irradiation source, said photocrosslinkable silicone composition X comprising:
• a) at least one organopolysiloxane A including at least one (meth)acrylate group
• b) at least one radical photoinitiator B represented by the formula (I):
• wherein:
• R represents a linear or branched C1-C50 alkylene or heteroalkylene group, optionally a linear or branched C1-C18 alkylene or heteroalkylene group, said alkylene and heteroalkylene groups comprising at least one siloxane function;
• R1 represents a group of formula (II):
• wherein Ar represents an aryl group of 6 to 18 carbon atoms, which is unsubstituted or substituted with at least one of the following groups:
• an alkyl group of 1 to 6 carbon atoms,
• an alkenyl group of 2 to 4 carbon atoms,
• a heteroatom O, N or S,
• a halogen,
• an SiMe3 group,
• a hydroxyl group (OH),
• a group (O-Alk) where Alk represents an alkyl group comprising from 1 to 15 carbon atoms, optionally from 1 to 12 carbon atoms, optionally from 1 to 10 carbon atoms, optionally from 1 to 5 carbon atoms, optionally CH3 or C2H5;
• R2 represents:
• a group R1,
• an aryl group of 6 to 18 carbon atoms, which is unsubstituted or substituted with at least one of the following groups:
• an alkyl group of 1 to 6 carbon atoms,
• an alkenyl group of 2 to 4 carbon atoms,
• a heteroatom O, N or S,
• a halogen,
• an SiMe3 group,
• a hydroxyl group (OH),
• a group (O-Alk) where Alk represents an alkyl group comprising from 1 to 15 carbon atoms, optionally from 1 to 12 carbon atoms, optionally from 1 to 10 carbon atoms, optionally from 1 to 5 carbon atoms, optionally CH3 or C2H5;
• ii) selectively irradiating at least a portion of the photocrosslinkable silicone composition X by means of the irradiation source to form a part of the silicone elastomer article;
• and
• iii) repeating step ii) a sufficient number of times to produce the silicone elastomer article.