Provided are a low-viscosity ultraviolet curable silicone composition capable of being used even in a surface exposure method and a lift-up method etc.; and a cured product superior in tensile strength and elongation at break. The ultraviolet curable silicone composition contains: (A) an organopolysiloxane; (B) a photopolymerization initiator; and (C) a monofunctional (meth)acrylate compound having no siloxane structure and/or (D) a multifunctional (meth)acrylate compound having no siloxane structure, wherein the organopolysiloxane is represented by the following general formula (1):

##STR00001## wherein n satisfies 1≤n≤1,000, m satisfies 1≤m≤1,000, Ar is an aromatic group, R.sup.1 represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, A is a group represented by the following formula (2):

##STR00002## wherein p satisfies 0≤p≤10, a satisfies 1≤a≤3, R.sup.1 represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, R.sup.2 represents an oxygen atom or an alkylene group, R.sup.3 represents an acryloyloxyalkyl group or the like.

Provided is a thermoplastic elastomer comprising a mesogen-silicon compound (co)polymer which is represented by formula (1) below and has a number average molecular weight of 1,000-500,000. The thermoplastic elastomer has transparency and rubber properties (rubber elasticity) and can be (repeatedly) molded thermally and reversibly, and thus can be suitably used in potting materials or various sealing materials. In formula (1), Ar represents a mesogenic group selected from among structures represented by formula (2) below, a represents an integer of 0.5-1, b represents a number of 0-0.5 (a and b respectively represent the ratio of the number of respective repeating units to the sum of all the repeating units in the molecule, and a+b=1), R.sup.1 is a monovalent hydrocarbon group that does not contain a C1-8 aliphatic unsaturated bond, and R.sup.2 is a hydrogen atom, —Si(CH.sub.3).sub.3, —Si(CH.sub.3).sub.2(OH), —Si(CH.sub.3).sub.2(CH═CH.sub.2) or —Si(CH.sub.3).sub.2(CH.sub.2—CH═CH.sub.2). ##STR00001##

Provided is a thermoplastic elastomer comprising a mesogen-silicon compound (co)polymer which is represented by formula (1) below and has a number average molecular weight of 1,000-500,000. The thermoplastic elastomer has transparency and rubber properties (rubber elasticity) and can be (repeatedly) molded thermally and reversibly, and thus can be suitably used in potting materials or various sealing materials. In formula (1), Ar represents a mesogenic group selected from among structures represented by formula (2) below, a represents an integer of 0.5-1, b represents a number of 0-0.5 (a and b respectively represent the ratio of the number of respective repeating units to the sum of all the repeating units in the molecule, and a+b=1), R.sup.1 is a monovalent hydrocarbon group that does not contain a C1-8 aliphatic unsaturated bond, and R.sup.2 is a hydrogen atom, —Si(CH.sub.3).sub.3, —Si(CH.sub.3).sub.2(OH), —Si(CH.sub.3).sub.2(CH═CH.sub.2) or —Si(CH.sub.3).sub.2(CH.sub.2—CH═CH.sub.2). ##STR00001##

The present invention relates to an oil-bleed self-bonding liquid silicone rubber composition having both self-bonding and self-lubricating capabilities. The oil-bleed self-bonding liquid silicone rubber composition exhibits self-bonding capability in particular to substrates that contain residual hydroxyl groups or other residual hydrosilyl-reacting groups on their surface, including polycarbonate, polyester, polyamide, polysulfone, polyurethane, phenolic resin, epoxy resin, cellulose, glass and the mixture thereof.

The present invention relates to silicone hydrogels exhibiting desired combinations of physical and mechanical properties, formed from a reactive monomer mixture comprising at least one N-alkyl methacrylamide, and at least one silicone-containing component. These silicone hydrogels may also contain hydrophilic components, crosslinking agents and toughening monomers. These silicone hydrogels are useful in preparing biomedical devices, ophthalmic lenses, and contact lenses.

The present invention relates to silicone hydrogels exhibiting desired combinations of physical and mechanical properties, formed from a reactive monomer mixture comprising at least one N-alkyl methacrylamide, and at least one silicone-containing component. These silicone hydrogels may also contain hydrophilic components, crosslinking agents and toughening monomers. These silicone hydrogels are useful in preparing biomedical devices, ophthalmic lenses, and contact lenses.

The present invention discloses a silicone rubber and a method for preparing it, and a phenolic modified silicone rubber resin and a method for preparing it. The structural formula of the silicone rubber is shown as follows:

##STR00001## Wherein x=70-80, y=10-20.

The structural formula of the phenolic-modified silicone rubber resin is shown as follows:

##STR00002## wherein n, x, y are degrees of polymerization, n=10-20, x=70-80, y=10-20. A method for preparing the phenolic-modified silicone rubber resin orderly comprises: adding 90-110 parts by mass of brominated phenolic resin and 180-220 parts of organic solvent into 100 parts by mass of silicone rubber, reacting at 70-80° C. for 24-48 h until the solution is clear and transparent; adding 9-11 parts by mass of capping agent, reacting for another 4-5 h to obtain a reaction liquid containing phenolic-modified silicone rubber resin. The phenolic-modified silicone rubber resin prepared in the present invention can solve the problem of easy pulverization in the ablation process of conventional silicone rubber and meanwhile has high mechanical properties.

The present invention discloses a silicone rubber and a method for preparing it, and a phenolic modified silicone rubber resin and a method for preparing it. The structural formula of the silicone rubber is shown as follows:

##STR00001## Wherein x=70-80, y=10-20.

The structural formula of the phenolic-modified silicone rubber resin is shown as follows:

##STR00002## wherein n, x, y are degrees of polymerization, n=10-20, x=70-80, y=10-20. A method for preparing the phenolic-modified silicone rubber resin orderly comprises: adding 90-110 parts by mass of brominated phenolic resin and 180-220 parts of organic solvent into 100 parts by mass of silicone rubber, reacting at 70-80° C. for 24-48 h until the solution is clear and transparent; adding 9-11 parts by mass of capping agent, reacting for another 4-5 h to obtain a reaction liquid containing phenolic-modified silicone rubber resin. The phenolic-modified silicone rubber resin prepared in the present invention can solve the problem of easy pulverization in the ablation process of conventional silicone rubber and meanwhile has high mechanical properties.

[Problem] To provide a polysiloxanecapable of forming a cured film of a thick film with high heat resistance, a composition comprising the polysiloxane, and a method of manufacturing a cured film using the composition. [Means for Solution] To provide a polysiloxane comprising a repeating unit represented by the following formula (Ib), wherein R.sup.2 is each independently hydrogen, alkyl, aryl, alkenyl, and the like, a composition comprising the polysiloxane, and a method of manufacturing a cured film using the composition.

##STR00001##

[Problem] To provide a polysiloxanecapable of forming a cured film of a thick film with high heat resistance, a composition comprising the polysiloxane, and a method of manufacturing a cured film using the composition. [Means for Solution] To provide a polysiloxane comprising a repeating unit represented by the following formula (Ib), wherein R.sup.2 is each independently hydrogen, alkyl, aryl, alkenyl, and the like, a composition comprising the polysiloxane, and a method of manufacturing a cured film using the composition.

##STR00001##