WO2016107533A1

WO2016107533A1 - Curable polysiloxane composition

Info

Publication number: WO2016107533A1
Application number: PCT/CN2015/099352
Authority: WO
Inventors: 贾丽亚; 满忠标
Original assignee: 蓝星有机硅（上海）有限公司
Priority date: 2014-12-31
Filing date: 2015-12-29
Publication date: 2016-07-07
Also published as: JP2018501380A; KR101943780B1; CN105802238A; CN105802238B; JP6465981B2; KR20170100613A

Abstract

The present application relates to a polysiloxane composition and a preparation method thereof, and to an element prepared from the polysiloxane composition, especially an optical element. In the polysiloxane composition, at least one of polysiloxane resins A2 is a polysiloxane resin comprising at least one siloxane unit M (M^Vi unit) having an alkenyl. In addition, the polysiloxane composition of the present appliction can further comprise an ultraviolet absorbent component D, which comprises one or more of benzotriazole compounds (Z) selected from formula Z.

Description

Curable silicone composition

Technical field

The present application relates to a silicone composition and a process for its preparation, and also to an element, in particular an optical element, made from the polysiloxane composition.

Background technique

With the rapid development of polymer technology and related research, more and more optical components and their components comprise or consist of polymeric materials. Compared with traditional inorganic materials, polymer materials not only maintain the excellent performance of traditional inorganic materials, but also have the advantages of light weight, low cost, simple process and good mechanical properties.

Optical polymer materials can be used for optical bonding, lens or optical sheets and substrates, and can be used in the following components: optical film, optical filter, CCD optical system, photographic equipment, optical communication and waveguide, optical fiber, light Sensors, holographic optics, interferometers, optical couplers, optical lenses such as microlenses, lenticular lenses, prismatic lenses, Fresnel lenses, and the like.

Polymers currently available for the preparation of optical components and their components are: polymethyl methacrylate, polyurethane, polycarbonate, polyvinyl chloride, polystyrene, polyester, epoxy, cycloolefin polymer, silicone Alkane, etc. Among them, polysiloxanes have attracted wide attention of researchers due to their excellent high temperature resistance, weather resistance, ultraviolet resistance, aging resistance and the like, and have been produced into various optical sheets, substrates or optical adhesives.

Polymer materials such as polymethyl methacrylate and polyvinyl chloride which can be used for the preparation of optical elements such as Fresnel lenses are disclosed in CN101675089A and CN102863709A. Such materials have high light transmittance and are easy to process, but they are prone to aging and deformation when they are in a cold, overheated, ultraviolet or other radiation environment, which may result in a decrease in lens performance stability or even failure to use.

Silicone materials have a series of excellent properties such as excellent weather resistance, high temperature resistance and yellowing resistance, and have obvious advantages over other materials. Therefore, silicone materials are used to prepare optical components. For example, CN102918093A proposes a polysiloxane-based optical material and a preparation method thereof, which are used in place of the conventional polymethyl acrylate or the like to avoid problems such as poor aging resistance. The silicone material is crosslinked by exposing the uncured silicone composition to an electron beam. However, this method requires special equipment and is costly.

Therefore, there is a need to further improve a silicone composition which can be rapidly cured at room temperature or a slightly higher temperature, and to develop a polymer which can absorb light waves of a certain region (such as ultraviolet light waves) and has outstanding aging resistance. Silicone compositions, which are of great significance for protecting related devices from UV damage.

Summary of the invention

The present application provides an addition curable silicone composition which has high clarity, good flowability, is easy to process, and is capable of rapid curing at room temperature or slightly elevated temperatures. In addition, the present application also enables the silicone composition to maintain excellent ultraviolet absorption even under relatively long-term aging conditions by adding a certain ultraviolet absorber, particularly a preferred ultraviolet absorber, thereby correlating the device. Play a long-term protection.

The optical element thus obtained has high light transmittance and excellent ultraviolet aging resistance. The silicone compositions according to the present application can be used in the preparation of optical adhesives, optical sheets or substrates and in a variety of optical structures or systems, particularly for the preparation of optical lenses such as Fresnel lenses.

A silicone composition according to the present application comprising:

(A) an alkenyl polysiloxane component comprising or consisting essentially at least one of from 0 to 99.9% by weight, based on the total weight of the polysiloxane A1 and the silicone resin A2, having at least two per molecule Polysiloxane A1 bonded to the alkenyl group on the silicon precursor with a weight of 0.1-100 5% by weight of at least one silicone resin A2 having at least two alkenyl groups bonded to a silicon atom per molecule,

The silicone resin A2 described therein comprises or consists essentially of:

At least two different siloxane units selected from the group consisting of siloxane units M of the formula R ₃ SiO _1/2 , siloxane units D of the formula R ₂ SiO _2/2 , siloxane units T of the formula RSiO _3/2 And a siloxane unit Q of the formula SiO _4/2 , wherein R represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably a monovalent aliphatic or aromatic group of 1 to 12, more preferably 1 to 8 carbon atoms Hydrocarbyl group,

Wherein at least one of the siloxane units is a siloxane unit T or Q, and at least one of the siloxane units M, D and T comprises an alkenyl group;

(B) a hydrogen-containing polysiloxane component comprising or substantially comprising

At least one hydrogen-containing polysiloxane B1 having at least one silicon hydrogen atom bonded to the same or different silicon atoms per molecule, or at least one silicon having at least one bonded to the same or different silicon atoms per molecule a hydrogen-containing polysiloxane resin B2 of a hydrogen atom or a mixture of the two,

Provided that the hydrogen-containing polysiloxane component comprises a total of at least two of said silicon hydrogen atoms;

(C) an effective amount of at least one hydrosilylation reaction catalyst.

In particular, the present application relates to a polysiloxane composition as described above, wherein at least one of the polysiloxane resins A2 is a siloxane unit M comprising at least one alkenyl group (M ^Vi unit) a silicone resin.

In particular, the present application relates to a polysiloxane composition as described above, wherein the composition further comprises (D) an ultraviolet absorber component D comprising one or more ultraviolet absorbers as described below A benzotriazole compound of the formula (Z) is preferred.

Component (A)

In the silicone composition of the present application, component (A) comprises a polysiloxane based The total weight of A1 and the silicone resin A2 is from 0 to 99.9% by weight of at least one polysiloxane A1 having at least two alkenyl groups bonded to the silicon precursor per molecule and 0.1 to 100% by weight At least one silicone resin A2 having at least two alkenyl groups bonded to a silicon atom per molecule. In component (A), an alkenyl group may be present at any position on the polysiloxane A1 backbone, for example at the end or in the middle or both ends of the molecular chain.

The polysiloxane A1 comprises:

(i) siloxane unit of formula (I-1)

among them

R ^x represents a C _2-12 , preferably C _2-6 alkenyl group, most preferably a vinyl or allyl group,

Z may represent, identically or differently, a monovalent hydrocarbon radical having from 1 to 30, preferably from 1 to 12, carbon atoms, preferably selected from C _1-8 alkyl, including alkyl optionally substituted by at least one halogen atom, And also preferably an aryl group selected from aryl groups, especially C _6-20 ,

a is 1 or 2, b is 0, 1 or 2 and the sum of a+b is 1, 2 or 3, and

(ii) optionally, other siloxane units of formula (I-2)

among them

Z has the meaning as described above and c is 0, 1, 2 or 3.

In a preferred embodiment, Z may be selected from the group consisting of methyl, ethyl, propyl, 3,3,3-trifluoropropyl groups, phenyl, xylyl, and tolyl groups. Preferably, at least 60 mol% of the group Z is a methyl group.

The polysiloxane A1 may have a viscosity at least equal to 50 mPa.s and preferably less than 200,000 mPa.s. In the present application, all viscosities are referred to as dynamic viscosity values, unless otherwise specified, and can be measured, for example, in a known manner at 20 ° C using a Brookfield instrument.

The polysiloxane A1 may be formed only of the unit of the formula (I-1) or may additionally comprise a unit of the formula (I-2). The polysiloxane A1 is a linear, branched or cyclic structure.

Examples of the siloxane unit of the formula (I-1) are a vinyldimethylsiloxy group, a vinylphenylmethylsiloxy group, a vinylmethylsiloxy group and a vinylsiloxane unit. .

Examples of the siloxane unit of the formula (I-2) are SiO _4/2 units, dimethylsiloxy group, methylphenylsiloxy group, diphenylsiloxy group, methylsilyloxy group And phenylsiloxy groups.

Examples of the polysiloxane A1 include linear or cyclic compounds such as dimethylpolysiloxane (including dimethylvinylsilyl end group), (methylvinyl) (dimethyl group) Polysiloxane copolymers (including trimethylsilyl end groups), (methylvinyl) (dimethyl)polysiloxane copolymers (including dimethylvinylsilyl end groups) and A cyclic methyl vinyl polysiloxane.

The silicone resin A2 is further contained in the component (A), and the content thereof may be 0.1 to 100% by weight, for example, 5 to 70% by weight based on the total weight of the polysiloxane A1 and the silicone resin A2. Or 10-40% by weight.

In the present application, the alkenyl polysiloxane resin A2 comprises:

At least two different siloxane units selected from the group consisting of siloxane units M of the formula R ₃ SiO _1/2 , siloxane units D of the formula R ₂ SiO _2/2 , siloxane units T of the formula RSiO _3/2 And a siloxane unit Q of the formula SiO _4/2 , wherein R represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, and

Provided that at least one of these siloxane units is a siloxane unit T or Q, and at least one of the siloxane units M, D and T contains an alkenyl group.

The inventors of the present application found that if all of the alkenyl groups in the polysiloxane resin A2 are substantially or wholly bonded to the siloxane unit M (M ^Vi unit), compared to other alkenyl bonding methods The silicone resin can result in a more rapid cure of the silicone composition of the present application at room temperature or at elevated temperatures.

The silicone resin as the siloxane unit M (M ^Vi unit) having an alkenyl group may be, for example, a silicone resin selected from the group consisting of (in the context, when the unit T, Q or D is mentioned) , the unit with the superscript "Vi" means the unit containing alkenyl):

An organopolysiloxane resin of the formula M ^Vi Q which consists essentially of the following units:

a monovalent siloxane unit M ^{Vi of the} formula R'R ₂ SiO _1/2 , and

a tetravalent siloxane unit Q of the formula SiO _4/2 , and

An organopolysiloxane resin of the formula MM ^Vi Q which consists essentially of the following units:

a monovalent siloxane unit M of the formula R ₃ SiO _1/2 , and

a monovalent siloxane unit M ^{Vi of the} formula R'R ₂ SiO _1/2 , and

a tetravalent siloxane unit Q of the formula SiO _4/2 , and

An organopolysiloxane resin of the formula M ^Vi T ^Vi Q consisting essentially of the following units:

(a) a monovalent siloxane unit M ^{Vi of the} formula R'R ₂ SiO _1/2 ,

(b) a trivalent siloxane unit T ^{Vi of the} formula R'SiO _3/2 , and

(c) a tetravalent siloxane unit Q of the formula SiO _4/2 ,

An organopolysiloxane resin of the formula M ^Vi TQ consisting essentially of the following units:

a trivalent siloxane unit T of the formula RSiO _3/2 ;

a monovalent siloxane unit M ^{Vi of the} formula R'R ₂ SiO _1/2 , and

a tetravalent siloxane unit Q of the formula SiO _4/2 , and

An organopolysiloxane resin of the formula M ^Vi DQ consisting essentially of the following units:

a divalent siloxane unit D of the formula R ₂ SiO _2/2 ;

a monovalent siloxane unit M ^{Vi of the} formula R'R ₂ SiO _1/2 , and

a tetravalent siloxane unit Q of the formula SiO _4/2 ,

among them

R represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably a monovalent aliphatic or aromatic hydrocarbon group of 1 to 12, more preferably 1 to 8 carbon atoms, and

R' represents an alkenyl group, preferably having 2 to 12, more preferably 2 to 6 carbon atoms Alkenyl, especially ethylene or allyl, most preferably vinyl.

The above are only some examples of the silicone resin A2, and it is apparent to those skilled in the art that other resins composed of the units M, T, D and Q are also suitable as the silicone resin A2 in the present application.

Although it is preferred that all of the alkenyl groups in the silicone resin A2 are bonded to M (M ^Vi unit), for example, the silicone resin having the alkenyl group siloxane unit M (M ^Vi unit) may be selected. An organopolysiloxane resin of the formula M ^Vi Q, the formula MM ^Vi Q, the formula M ^Vi TQ and the formula M ^Vi DQ, etc., particularly preferably an organopolysiloxane resin selected from the group consisting of MM ^Vi Q, but according to production practice It is also desirable or small, depending on the curing rate, that a small amount of an alkenyl linkage is present on D or T, provided that the amount of alkenyl groups bonded to unit M constitutes the total alkenyl content of said polysiloxane resin A2. The proportion should be greater than 50%, preferably greater than 60%, more preferably greater than 80%, and most preferably greater than 90%.

In an advantageous embodiment of the present application, the content of the alkenyl group in the silicone resin A2 is 0.001 mol or more, preferably 0.01 mol or more, for example, 0.03 to 0.2 mol, based on 100 g of the polysiloxane resin A2. , or 0.06 to 0.1 mol.

In the silicone resin A2, in addition to the silicone resin having a M ^Vi unit as described above, for example, one or more organopolysiloxane resins selected from the group consisting of the following groups may be contained. :

An organopolysiloxane resin of the formula MT ^Vi Q consisting essentially of the following units:

(a) a trivalent siloxane unit T ^{Vi of the} formula R'SiO _3/2 ;

(b) a monovalent siloxane unit M of the formula R ₃ SiO _1/2 , and

(c) a tetravalent siloxane unit Q of the formula SiO _4/2 ,

An organopolysiloxane resin of the formula MD ^Vi Q consisting essentially of the following units:

(a) a divalent siloxane unit D ^{Vi of the} formula RR'SiO _2/2 ;

(b) a monovalent siloxane unit M of the formula R ₃ SiO _1/2 , and

(c) a tetravalent siloxane unit Q of the formula SiO _4/2 , and

An organopolysiloxane resin of the formula MDD ^Vi Q, which consists essentially of the following units:

(a) a divalent siloxane unit D ^{Vi of the} formula RR'SiO _2/2 ;

(b) a divalent siloxane unit D of the formula R ₂ SiO _1/2 ,

(c) a monovalent siloxane unit M of the formula R ₃ SiO _1/2 , and

(d) a tetravalent siloxane unit Q of the formula SiO _4/2 ,

among them

R' represents an alkenyl group, preferably an alkenyl group having 2 to 12, more preferably 2 to 6 carbon atoms, particularly preferably ethylene or allyl group, most preferably a vinyl group.

As described above, although other silicone resins having the above structures may be used, it is necessary to ensure that the content of the alkenyl group bonded to the unit M in the entire silicone resin A2 accounts for the polysiloxane. The proportion of all alkenyl groups in the alkane resin A2 should be greater than 50%, preferably greater than 60%, more preferably greater than 80%, and most preferably greater than 90%.

In the context of the present application, when referring to a composition, in particular a silicone resin or components (A) and (B), the term "substantially...composition/inclusion" is used to mean a related resin or combination. The compositions contain more than 50% by weight, such as at least 60% by weight, at least 70% by weight, or at least 80% by weight, or even 100% by weight, based on the total weight of the composition.

Advantageously, the silicone resin A2 has a weight average molecular weight in the range of from 200 to 100,000, preferably from 200 to 50,000, more preferably from 500 to 30,000. Here, the weight average molecular weight can be obtained by gel permeation chromatography using polystyrene as a standard conversion.

Component (B)

Component (B) of the polysiloxane composition of the present application comprises at least one hydrogen-containing polysiloxane having at least one silicon hydrogen atom bonded to the same or different silicon atoms per molecule. An alkane B1, or at least one hydrogen-containing polysiloxane resin B2 having at least one silicon hydrogen atom bonded to the same or different silicon atoms per molecule or a mixture of the two, provided that the hydrogen-containing polysiloxane The component comprises a total of at least two of said silicon hydrogen atoms.

Therefore, as component (B), at least one hydrogen-containing polysiloxane B1 having at least two silicon hydrogen atoms bonded to the same or different silicon atoms per molecule or at least one per molecule may be used. A mixture of hydrogen-containing polysiloxanes B1 bonded to silicon hydrogen atoms on the same or different silicon atoms.

The organopolysiloxane having a SiH group is capable of undergoing a crosslinking reaction with other components, particularly component (A), by reacting a SiH group in the component with an alkenyl group in the other component. A cured product is formed. In the hydrogen-containing polysiloxane B1 having at least one or two hydrogen atoms bonded to the same or different silicon atoms per molecule, it is preferred to have two, three or more SiH groups per molecule. group.

In a preferred embodiment, the hydrogen-containing polysiloxane B1 comprises

(i) siloxane units of formula (II-1):

among them

L may represent, together or differently, a monovalent hydrocarbon radical, preferably selected from C _1-8 alkyl radicals, including alkyl radicals optionally substituted by at least one halogen atom, and also preferably selected from aryl radicals, in particular C _6-20 Aryl group,

d is 1 or 2, e is 0, 1 or 2 and the sum of d+e is 1, 2 or 3,

And (ii) optionally, at least one other unit of the average formula (II-2)

among them

L has the meaning as described above and g is 0, 1, 2 or 3.

In a more preferred embodiment, L may be selected from the group consisting of methyl, ethyl, propyl, 3,3,3-trifluoropropyl, phenyl, xylyl, and tolyl, and the like.

The hydropolysiloxane B1 has a dynamic viscosity of at least equal to 10 mPa.s and preferably between 20 and 1000 mPa.s.

The hydrogen-containing polysiloxane B1 may be formed only of the unit of the formula (II-1) or may additionally comprise a unit of the formula (II-2). The hydrogen-containing polysiloxane B1 may have a linear, branched, or cyclic structure.

Examples of the unit of the formula (II-1) are H(CH ₃ ) ₂ SiO _1/2 , HCH ₃ SiO _2/2 and H(C ₆ H ₅ )SiO _2/2 .

Examples of the unit of the formula (II-2) may then be the same as those given above for the unit of the formula (I-2).

Examples of the hydrogen-containing polysiloxane B1 include a linear or cyclic compound such as dimethylpolysiloxane (including hydrogenated dimethylsilyl end group) having (dimethyl) (hydrogen group) a copolymer of a polysiloxane unit (including a trimethylsilyl end group), a copolymer having a (dimethyl)(hydromethyl)polysiloxane unit (including a hydrogenated dimethylsilyl group) End group), a hydrogenated methylpolysiloxane having a trimethylsilyl end group and a cyclic hydrogenated methylpolysiloxane.

In some cases, the hydrogen-containing polysiloxane B1 may be a dimethylpolysiloxane containing a hydrogenated dimethylsilyl end group and an organopolysiloxane containing at least three hydrosilyl groups. mixture.

As an alternative to component (B), it is also possible to use at least one hydrogen-containing polysiloxane resin B2 having at least two silicon-hydrogen atoms bonded to the same or different silicon atoms per molecule, or may be used At least one mixture of hydrogen-containing polysiloxane resin B2 having at least one silicon hydrogen atom bonded to the same or different silicon atoms per molecule.

The hydrogen-containing polysiloxane resin B2 comprises:

At least two different siloxane units selected from the formula R M ₃ SiO _1/2 siloxane units of the formula R D ₂ SiO _2/2 siloxane unit of formula RSiO _3/2 siloxane a unit T and a siloxane unit Q of the formula SiO _4/2 , wherein R represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, and

Provided that at least one of these siloxane units is a siloxane unit T or Q, and at least one of the siloxane units M, D and T contains a hydrosilyl group.

Therefore, according to a preferred embodiment, the hydrogen-containing silicone resin B2 may be selected from the group consisting of:

a hydrogen-containing silicone resin of the formula M'Q, which consists essentially of the following units:

(a) a monovalent siloxane unit M' of the formula R ₂ (H)SiO _1/2 , and

(b) a tetravalent siloxane unit Q of the formula SiO _4/2 , and

a hydrogen-containing silicone resin of the formula MD'Q, which consists essentially of the following units:

a divalent siloxane unit D' of the formula (R)(H)SiO _2/2 ,

a monovalent siloxane unit M of the formula R ₃ SiO _1/2 , and

a tetravalent siloxane unit Q of the formula SiO _4/2 ,

Wherein R represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably a monovalent aliphatic or aromatic hydrocarbon group of 1 to 12, more preferably 1 to 8 carbon atoms.

Further, as a further alternative, at least one hydrogen-containing polysiloxane B1 having at least one hydrogen atom bonded to the same or different silicon atoms per molecule and at least one bond having at least one bond per molecule may be employed. A mixture of hydrogen-containing polysiloxane resins B2 of hydrogen atoms on the same or different silicon atoms is referred to as component B). In this case, the polysiloxane B1 and the polysiloxane resin B2 may be mixed in a wide range in any ratio, and the mixing ratio may be based on desired product properties such as hardness and ratio of silicon to hydrogen to alkenyl groups. Wait to adjust.

Although in practice, at least one of the alkenyl polysiloxane components A comprising at least two bonds bonded to the silicon atom per molecule is generally employed, respectively, and at least one of the molecules having at least two bonds per molecule is the same or different Hydrogen-containing polysiloxane component B of a hydrogen atom on a silicon atom, but theoretically it is not excluded that it can be used while having an alkenyl group in the polysiloxane chain. And a hydrosilyl-based polymer, in which case they are generally classified as an alkenyl polysiloxane group according to whether the molar ratio of the alkenyl group and the hydrosilyl group in the polysiloxane exceeds 50 mol%, respectively. The fraction (A) (the majority of the alkenyl group) and the component (B) containing the hydrogen-containing polysiloxane (the majority of the silicon-hydrogen group).

The ratio of the components A and B is usually determined by the molar ratio of silicon to hydrogen and the vinyl group, and the molar ratio of the silicon hydrogen to the vinyl group is usually from 0.5 to 10, preferably from 0.8 to 6, more preferably from 1.2 to 4.

The total content of components A and B is generally more than 50% by weight of the total component, usually more than 60% by weight, more preferably 80% by weight or more.

Component (C)

The polysiloxane composition according to the present application further comprises an effective amount of at least one hydrosilylation reaction catalyst as component (C). In the polysiloxane composition according to the present application, the alkenyl polysiloxane component (A) and the hydrogen-containing polysiloxane component (B) are usually cured by a hydrosilylation reaction in the presence of a catalyst.

The hydrosilylation reaction catalyst used in such a reaction is usually a catalyst comprising at least one platinum group metal, and the curing catalyst comprising a platinum group metal is composed of at least one metal or compound of a platinum group, which is known per se. The so-called platinum group metals are also referred to as platinum group metals, and the term includes, in addition to platinum, ruthenium, rhodium, palladium, osmium and iridium. Preference is given to using compounds of platinum and rhodium. Platinum complexes and organic products are described, for example, in the patents US-A-3 159 601, US-A-3 159 602, US-A-3 220 972, EP-A-0 057 459, EP-A-0 188 And s. a complex of platinum with a vinyl organosiloxane. The entire contents of the above patents are incorporated herein by reference.

At least one hydrosilylation reaction catalyst according to the present application is present in the composition in a catalytically effective amount. Such catalytically effective amounts are known to those skilled in the art and can be readily determined depending on the amount and type of reactants. In general, in The content of the catalyst in the present application may be, for example, in the range of from 0.1 to 1,000 ppm, preferably from 0.5 to 400 ppm, more preferably from 1 to 50 ppm, based on the weight of the component (A), based on the weight of the metal.

A generally preferred catalyst is platinum.

UV absorber component D

As a preferred embodiment, the polysiloxane composition according to the present application further comprises an ultraviolet absorber component D.

Examples of the ultraviolet absorber commonly used in the art include salicylates, benzophenones, cyanoacrylates, triazines, benzotriazoles, cinnamic acid derivatives, and dibenzoylmethane derivatives. Etc., they are disclosed, for example, in CN101277676A, US20130344013A1, and CN102510861A.

For example, the phenone-based ultraviolet absorber suitable for the present application may be a benzophenone, a benzophenone or a diphenylethylenedione, and among them, a diphenylethylenedione ultraviolet absorber is preferred.

For example, a diphenylethylenedione ultraviolet absorber suitable for the present application may preferably be one or more of the following: diphenylethylenedione, 4,4-dihydroxydiphenylethanedione, 1-(4) -ethylphenyl)-3-(4-methoxyphenyl)propane-1,3-dione, 1-(4-t-butylphenyl)-3-(4-ethoxyphenyl) Propane-1,3-dione, 1-(4-propylphenyl)-3-(4-methoxyphenyl)propane-1,3-dione, 1-(4-tert-butylphenyl) --3-(4-methoxyphenyl)propane-1,3-dione, particularly preferably 1-(4-t-butylphenyl)-3-(4-methoxyphenyl)propane -1,3-dione.

For example, a cyanoacrylate UV absorber suitable for the present application may preferably be selected from one or more of the following: 2-cyano-3,3-diphenyl-2-acrylic acid-3-hydroxy-2 ,2-dimethylpropyl ester, 2-carbonitrile-3,3-diphenylhexylethyl ester, ethyl 2-cyano-3,3-diphenylacrylate, 2-cyano-3, Methyl 3-diphenylacrylate, isooctyl 2-cyano-3,3-diphenylacrylate. Particularly preferred is 2-cyano-3,3-diphenylpropene Isooctyl acid ester.

For example, a benzotriazole-based ultraviolet absorber suitable for the present application may preferably be selected from one or more of the following: 2-(2'H-benzotriazol-2'-yl)-4,6- Bis(tert-amyl)phenol N-oxide, 2-(2'H-benzotriazol-2'-yl)-4-methyl-6-(2'-propenyl)phenol, 2-(2 'H-benzotriazol-2'-yl)-4-1,1,3,3-tetramethylbutoxypropenyl and cresoltrizole trisiloxane.

However, when polymeric optical materials such as silicone materials are used in outdoor or complex environments, they are subject to aging effects. For example, a solar photovoltaic concentrating system needs to converge a large amount of sunlight for a long time on a small-area solar cell system to improve photoelectric conversion efficiency. In such long-term outdoor use, the ultraviolet rays in the sunlight will continuously damage the constituent elements of the concentrating system, making it easy to age, resulting in reduced performance and shortened service life.

The inventors of the present application have unexpectedly discovered that if a specific ultraviolet absorber is used, the product has good light transmittance and ultraviolet absorption effect in the initial state, and in the case of long-term aging, for example, high temperature accelerated aging test condition at 150 ° C. After aging for 24 hours, the cured composition still maintained good light transmission and ultraviolet absorption.

The specific ultraviolet absorber component D according to the present application contains at least one benzotriazole compound selected from the formula Z shown below. When they are used in the silicone composition, it is possible to bring about an improvement in the ultraviolet absorption effect as described above.

among them

Y1 is -H, -Cl, -Br;

Y2 is -H, C ₁ -C ₁₂ alkyl, -Cl, C ₁ -C ₁₂ alkoxy, C ₇ -C ₉ phenylalkyl, -C _n H _2n -COOX, wherein n is 0-4 and X is a C ₁ -C ₂₀ alkyl group, or a siloxane-substituted C ₁ -C ₁₂ alkyl group, a C ₁ -C ₁₂ alkoxy group, a C ₇ -C ₉ phenylalkyl group, and a -C _n H _{2n group} -COOX;

Y3 is -H, C ₁ -C ₁₂ alkyl, C ₁ -C ₁₂ alkoxy, phenyl, -Cl, (C ₁ -C ₈ alkyl)phenyl, C ₅ -C ₆ cycloalkyl, C ₂ -C ₉ alkoxyacyl, carboxyethyl, C ₇ -C ₉ phenylalkyl, or siloxane-substituted C ₁ -C ₁₂ alkyl, C ₁ -C ₁₂ alkoxy, phenyl, (C ₁ -C ₈ alkyl)phenyl, C ₅ -C ₆ cycloalkyl, C ₂ -C ₉ alkoxyacyl, carboxyethyl, C ₇ -C ₉ phenylalkyl.

Preferably, Y1 represents H.

Preferably, Y2 represents C ₃ -C ₁₂ alkyl, C ₇ -C ₉ phenylalkyl, -C _n H _2n -COOX, wherein n represents 1-3 and/or X represents a C ₁ -C ₁₂ alkyl group Or a siloxane-substituted C ₁ -C ₁₂ alkyl group; more preferably Y 2 represents a C ₃ -C ₁₂ alkyl group, a siloxane-substituted C ₁ -C ₁₂ alkyl group or -C _n H _2n -COOX, Wherein n represents 1-3 and/or X represents a C ₃ -C ₁₂ alkyl group.

Preferably, Y3 represents C ₁ -C ₄ alkoxy, phenyl, -Cl or C ₁ -C ₁₂ alkyl, siloxane-substituted C ₁ -C ₁₂ alkyl, more preferably C ₁ -C ₈ alkane A C ₁ -C ₁₂ alkyl group substituted with a siloxane group.

Preferred benzotriazole compounds may be selected, for example, from the group consisting of 2-(2'-hydroxy-3',5'-di-tert-amylphenyl)benzotriazole, 2-(2'-hydroxy-3'-(two (Trimethylsiloxy)methylsilylisobutyl)-5'-hexyl)benzotriazole and 3-(2'H-benzotriazole)-5-(1',1'-di Methyl ethyl)-4-hydroxy-phenylpropyl octyl ester. The most preferred of these is 3-(2'H-benzotriazole)-5-(1',1'-dimethylethyl)-4-hydroxy-phenylpropyl octyl ester.

Thus, according to a specific embodiment, the present application is also directed to a silicone composition comprising:

(A) an alkenyl polysiloxane component comprising or consisting essentially at least one of from 0 to 99.9% by weight, based on the total weight of the polysiloxane A1 and the silicone resin A2, having at least two per molecule a polysiloxane A1 bonded to an alkenyl group on the silicon precursor and 0.1 to 100% by weight of at least one polycondensation having at least two alkenyl groups bonded to a silicon atom per molecule Silicone resin A2,

The silicone resin A2 described therein comprises or consists essentially of:

And at least one of the siloxane units is a siloxane unit T or Q, and at least one of the siloxane units M, D and T comprises an alkenyl group;

(C) an effective amount of at least one hydrosilylation reaction catalyst;

(D) UV absorber component D selected from the benzotriazole compound of formula Z as described above.

Of these, 3-(2'H-benzotriazole)-5-(1',1'-dimethylethyl)-4-hydroxy-phenylpropyl octyl ester is most preferred.

The ultraviolet absorber is contained in an amount of 0.001 to 15% by weight, preferably 0.005 to 5% by weight, more preferably 0.01 to 3% by weight based on the total amount of the component.

When the ultraviolet absorber is added, since the ultraviolet absorber contains a group which usually has a strong polarity, and the polysiloxane system has a weak polarity, it often leads to poor compatibility between the two, which may cause polysiloxane. The transparency of the alkane system decreases. Therefore, a suitable organic solubilizing agent can be introduced to increase the ultraviolet absorber and the silicone composition, where appropriate. The compatibility improves the ability of the silicone composition to absorb ultraviolet rays while maintaining transparency and other properties to achieve the object of the invention.

The preferred organic solubilizer may be selected from one or more of the following: aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, alcohols, ethers, esters, ketones, halogenated hydrocarbons, aldehydes, nitrogen-containing The compound or the heterocyclic compound is preferably, for example, an aliphatic hydrocarbon or an aromatic hydrocarbon.

The aliphatic hydrocarbons may be selected from one or more of the following: but not limited to the following: cyclohexane, n-hexane, butane, n-heptane, pentane, isodecane, etc., preferably isomeric dodecane.

The aromatic hydrocarbons may be selected from one or more of the following: but not limited to the following: benzene, toluene, xylene, cumene, n-propylbenzene, p-toluene, C _12-15 alcohol benzoate, etc., preferably C _12-15 alcohol benzoate.

The amount of solvent added is generally no more than 30%, preferably no more than 10%, more preferably no more than 2% of the total amount in the formulation.

Due to the variety of UV absorbers, the molecular structure and silicone compatibility difference will be great, so not all solutions need to add organic solubilizer. In addition, by adding some methods such as increasing the stirring speed or prolonging the stirring time, it is also possible to add the ultraviolet absorber under certain conditions without affecting the transparency of the composition.

In addition to the above components, the reaction inhibitor E may also be contained in the polysiloxane composition according to the present application.

The hydrosilylation reaction is often catalyzed by a platinum catalyst with very fast reaction kinetics. To further meet the requirements of the composition for preparation, shipping, storage or formulation time, a small amount of hydrosilylation reaction inhibitor is typically added.

An acetylene alcohol type curing inhibitor or a polyvinyl type curing inhibitor or a mixture thereof can be usually used here. These inhibitors are disclosed, for example, in the following patents: EP0794217A1, US20140004359, CN102277128A, CN103554924A and CN103655212A. Here, the entire contents of these patents are also incorporated herein by reference. In the manual.

Examples of the acetylenic alcohol inhibitor may be: 3-butyn-2-ol, 1-pentyn-3-ol, 1-hexyn-3-ol, 1-heptyn-3-ol, 5- Methyl-1-hexyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynyl-1-cyclopentanol, 1-ethynyl-1-cyclohexanol , 1-ethynyl-1-cycloheptanol, 3-ethyl-1-hexyn-3-ol, 3-ethyl-1-heptyn-3-ol, 3-isobutyl-5-methyl 1-hexyn-3-ol, 3,4,4-trimethyl-1-pentyn-3-ol, 3-ethyl-5-methyl-1-heptyn-3-ol, 4- Ethyl-1-octyn-3-ol, 3,7,11-trimethyl-1-dodecyn-3-ol, 1-ethynyl-1-cyclooctanol, 3-methyl-1- Butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3-methyl-1-hexyn-3-ol, 3-methyl-1-heptyn-3-ol, 3 -Methyl-1-octyn-3-ol, 3-methyl-1-indolyl-3-ol, 3-methyl-1-decyn-3-ol, 3-methyl-1-12 Alkyn-3-ol, 3-ethyl-1-pentyn-3-ol.

Examples of the polyvinyl-based inhibitor may be: tetramethyldivinylsilane, polyvinyl silicone oil, tetramethyltetravinylcyclotetrasiloxane, preferably tetramethyltetravinylcyclotetrasiloxane .

For the addition curable silicone composition of the present application, the polymerization inhibitor may not be added when it can meet the requirements for preparation, transportation, storage or use formulation time without the addition of an inhibitor.

Other components

In the polysiloxane composition of the present application, in addition to the above components (A) to (C), one or more other components such as an antistatic agent, a radiation shielding agent, and a radical suppression may be further included. Agent, adhesive modifier, flame retardant additive, surfactant, storage stability improver, ozone degradation inhibitor, light stabilizer, viscosity builder, plasticizer, antioxidant, heat stabilizer, and Other additives, provided that the amount added does not affect the curing speed, light transmittance and mechanical properties of the silicone composition, making the composition unusable for the preparation of optical adhesives or optical components and for optical systems in.

The polysiloxane composition according to the present application can be obtained by using the individual components as described (A) to (D) or (A) to (E) are obtained by uniformly mixing in proportion with other optional additives. The cured silicone composition is then prepared via a hydrosilylation reaction.

DRAWINGS

Figure 1 is the light transmittance of the cured silicone composition of Examples 1-4.

Figure 2 is the light transmittance of the cured silicone composition of Examples 5, 7-8.

Figure 3 is the light transmittance of the cured silicone composition of Example 6.

4 is a light transmittance of the cured silicone composition in Example 9.

Figure 5 is the light transmittance of the cured silicone composition of Example 10.

Figure 6 is a graph showing the light transmittance of the cured silicone composition in Example 11.

The present application is further described below in conjunction with the embodiments. However, the application is not limited to the following embodiments. In addition, percentage data and share ratios in the specification of the present application are by weight unless explicitly stated otherwise.

Example 1

32 parts of Resin 11342 (from Bluestar Silicones, where 621V3500: 621V60000: MM ^Vi Q = 40:20:40 (weight ratio), 621V3500 and 621V60000 are vinyl doubles having a viscosity of about 3500 mPa.s and about 60,000 mPa.s. The blocked polydimethylsiloxane has a vinyl content of 0.007 mol/100 g and 0.003 mol/100, a total vinyl content of about 0.041 mol/100 g), 41 parts by weight of 621 V3500, and 27 parts by weight of 621 V10000 (from Blue Star). Silicone Company, vinyl terminated polydimethylsiloxane with a viscosity of about 10000 mPa.s, ethylene content 0.005 mol/100 g), 0.03 parts by weight H50614 (from Bluestar Silicone, tetramethyltetravinylcyclotetracycline Siloxane) and a platinum complex catalyst with a platinum content of 2.8 ppm (from Shanghai Heraeus Industrial Technology Materials Co., Ltd., platinum (0)-divinyltetramethyldisiloxane complex) at high speed stirring The mixture was stirred 3 times at 2000 rpm, and stirred for 20 seconds each time.

After thorough mixing, 5 parts by weight of hydrogen-containing polysiloxane Resin 10339 (from Bluestar Silicones, Si(O(CH ₃ ) ₂ SiH) ₄ , CAS: 68988-57-8) was added. The mixture was stirred 3 times at 2000 rpm in a high-speed stirrer, and stirred for 20 seconds each time.

The above mixture was cured at 45 ° C for 1 hour, thereby obtaining a cured silicone composition.

Example 2

76 parts by weight of Resin 11342, 24 parts by weight of 621V3500, 0.03 parts by weight of H50614, and a platinum complex catalyst having a platinum content of 2.9 ppm were mixed in a high-speed stirrer at 2000 rpm for 3 times, and stirred for 20 seconds each time.

After thorough mixing, add 9 parts by weight of hydrogen-containing polysiloxane 626V25H7 (from Bluestar Silicones, hydrogen-bonded polydimethylsiloxane with hydrogen bonds at both ends of the chain and a chain with a silicon hydrogen content of 0.69 mol) /100g). The mixture was stirred 3 times at 2000 rpm in a high-speed stirrer, and stirred for 20 seconds each time.

Example 3

53 parts by weight of Resin 11342, 9 parts by weight of Resin 10340 (from Bluestar Silicones, wherein 621V3500: MD ^Vi Q = 75:25 (weight ratio), total vinyl content of 0.021 mol / 100 g), 38 parts by weight of 621V3500 0.03 parts by weight of H50614 and a platinum complex catalyst having a platinum content of 3.0 ppm were mixed by stirring three times at 2000 rpm in a high-speed stirrer, and stirred for 20 seconds each time.

After thorough mixing, 6.6 parts by weight of Resin 10339 and 5.4 parts by weight were added. 620H2 (from Bluestar Silicones, hydrogen terminated polydimethylsiloxane, having a silicon hydrogen content of 0.19 mol/100 g). The mixture was stirred 3 times at 2000 rpm in a high-speed stirrer, and stirred for 20 seconds each time.

The above mixture was cured at 45 ° C until the hardness was stabilized, thereby obtaining a cured silicone composition.

Example 4

56 parts by weight of Resin 11342, 44 parts by weight of 621V3500, 0.03 parts by weight of H50614, and a platinum complex catalyst having a platinum content of 3.0 ppm were mixed in a high-speed stirrer at 2000 rpm for 3 times, and stirred for 20 seconds each time.

After thorough mixing, 6.5 parts by weight of Resin 10339 and 5.4 parts by weight of 620H2 were further added. The mixture was stirred 3 times at 2000 rpm in a high-speed stirrer, and stirred for 20 seconds each time.

Example 5

32 parts of Resin 11342, 41 parts by weight of 621V3500, 27 parts by weight of 621V10000, 0.03 parts by weight of H50614 and a platinum complex catalyst having a platinum content of 2.8 ppm were mixed in a high-speed stirrer at 2000 rpm for 3 times, each time. Stir for 20 seconds.

After thorough mixing, 5 parts by weight of Resin 10339 and 0.55 parts by weight of Ciba TINUVIN 384-2 (ultraviolet absorber, main component: 3-(2'H-benzotriazole)-5-(1', 1') were added. -Dimethylethyl)-4-hydroxy-phenylpropyl octyl ester from BASF) and solvent PAESTER 9145SD (main component C _12-15 alcohol benzoate from Patek Precision Chemical Co., Ltd.) Wherein the ratio of solvent to ultraviolet absorber is 1:4. The mixture was stirred 3 times at 2000 rpm in a high-speed stirrer, and stirred for 20 seconds each time.

The above mixture was cured at 45 ° C for 1 hour, thereby obtaining a cured silicone composition. The cured sample was stored at 150 ° C for 24 hours, and then the light transmittance was examined.

The structure of related substances is as follows:

Ciba TINUVIN 384-2

PAESTER 9145SD

Example 6

After thorough mixing, 6.5 parts by weight of Resin 10339 and 5.4 parts by weight of 620H2, and 18.10 parts by weight of the ultraviolet absorber Ciba TINUVIN 400 (CAS: 153519-44-9, whose composition and related substance structure are shown below) were added. A mixture of solvents PAESTER 9145SD wherein the ratio of solvent to UV absorber is 334:1. The mixture was stirred 3 times at 2000 rpm in a high-speed stirrer, and stirred for 20 seconds each time.

The structure of related substances is as follows:

Ciba TINUVIN 400: 2-[4-[2-Hydroxy-3-tridecyloxypropyl]oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl) -1,3,5-triazine and 2-[4-[2-hydroxy-3-dodecyloxypropyl]oxy]-2-hydroxyphenyl]-4,6-bis (2, a mixture of 4-dimethylphenyl)-1,3,5-triazine

Example 7

53 parts by weight of Resin 11342, 9 parts by weight of Resin 10340, 38 parts by weight of 621V3500, 0.03 parts by weight of H50614, and a platinum complex catalyst having a platinum content of 3.0 ppm were mixed in a high-speed stirrer at 2000 rpm for 3 times. Stir for 20 seconds each time.

After thorough mixing, 6.6 parts by weight of Resin 10339, 5.4 parts by weight of 620H2, and 0.46 parts by weight of Ciba TINUVIN 384-2 were further added. The mixture was stirred 3 times at 2000 rpm in a high-speed stirrer, and stirred for 20 seconds each time.

The above mixture was cured at 45 ° C until the hardness was stabilized, thereby obtaining a cured silicone composition. The cured sample was stored at 150 ° C for 24 hours, and then the light transmittance was examined.

Example 8

After thorough mixing, 6.5 parts by weight of Resin 10339 and 5.4 parts by weight of 620H2, and 0.47 parts by weight of the ultraviolet absorber Ciba TINUVIN 384-2 were further added. The mixture was stirred 3 times at 2000 rpm in a high-speed stirrer, and stirred for 20 seconds each time.

Example 9

56 parts by weight of Resin 11342, 44 parts by weight of 621V3500, 0.03 parts by weight of H50614, and a platinum complex catalyst having a platinum content of 3.1 ppm were mixed in a high-speed stirrer at 2000 rpm for 3 times, and stirred for 20 seconds each time.

After thorough mixing, 6.5 parts by weight of Resin 10339 and 5.4 parts by weight of 620H2, and 0.62 parts by weight of the ultraviolet absorber Ciba TINUVIN 384-2 were further added. The mixture was stirred 3 times at 2000 rpm in a high-speed stirrer, and stirred for 20 seconds each time.

Example 10

After thorough mixing, 6.6 parts by weight of Resin 10339 and 5.4 parts by weight were added. 620H2, and 1.3 parts by weight of UV absorber PARSOL GUARD (from DSM, the main component: 1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)propane-1, A mixture of 3-dione and 2-cyano-3,3-diphenylisooctyl acrylate with a solvent isomeric dodecane wherein the ratio of solvent to UV absorber is 1:1. The mixture was stirred 3 times at 2000 rpm in a high-speed stirrer, and stirred for 20 seconds each time.

The structure of related substances is

1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)propane-1,3-dione

2-cyano-3,3-diphenylisooctyl acrylate

Isomerized dodecane

Example 11

After thorough mixing, 6.5 parts by weight of Resin 10339 and 5.4 parts by weight of 620H2, and 0.47 parts by weight of an ultraviolet absorber Ciba TINUVIN 292HP (CAS: 41556-26-7, material structure shown below) were further added. The mixture was stirred 3 times at 2000 rpm in a high-speed stirrer, and stirred for 20 seconds each time.

The structure of related substances is as follows:

Ciba TINUVIN 292HP: bis(1,2,2,6,6-pentamethylpiperidinol) sebacate

Example 12

88.9 parts by weight of Resin 10340, 11.1 parts by weight of 621V60000, 0.03 parts by weight of H50614, and a platinum complex catalyst having a platinum content of 3.0 ppm were mixed in a high-speed stirrer at 2000 rpm for 3 times, and stirred for 20 seconds each time.

After thorough mixing, 4.9 parts by weight of Resin 10339 and 4 parts by weight of 620H2 were added. The mixture was stirred 3 times at 2000 rpm in a high-speed stirrer, and stirred for 20 seconds each time.

The above mixture was cured at 45 °C.

Example 13

88.9 parts by weight of Resin 10340, 11.1 parts by weight of 621V60000, and a platinum complex catalyst having a platinum content of 3.0 ppm were mixed in a high-speed stirrer at 2000 rpm for 3 times, and stirred for 20 seconds each time.

The above mixture was cured at 45 °C.

Performance evaluation

Each of the obtained compositions was evaluated in the following manner, and the results are shown in Table 1 and Figs. 1 to 5.

Appearance: The composition was cured at a low temperature of 45 ° C for 45 minutes to obtain a silicone material. The appearance was observed by visual observation.

Light transmittance: The polysiloxane composition prepared as described above was cured at 45 ° C to obtain a colorless transparent test piece having a thickness of 1 mm, and the light transmittance at 450 nm was measured using a UV-2600 ultraviolet spectrophotometer.

UV absorption performance: The same sample preparation and test method were adopted as the light transmittance, and the relevant light transmittance curve was obtained. The results are shown in Figures 1 to 6.

Hardness: The hardness was measured in accordance with ASTM D2240.

Viscosity: The viscosity was measured according to ASTM D445.

Tensile strength: The tensile strength was measured in accordance with ASTM D412. Curing conditions: 1 hour at 45 °C.

Tensile elongation: The tensile strength was measured in accordance with ASTM D412. Curing conditions: 45 ° C Next hour.

Tear Strength: Tear strength was determined according to ASTM D624A. Curing conditions: 1 hour at 45 °C.

As can be seen from the results of Table 1 and Figures 1-6, the polysiloxane compositions according to Examples 1-5 and 7-10 of the present invention were compared to the resin Example 12 in which the MM ^Vi Q unit was not employed. And 13, the former has a faster cure rate at 45 ° C and cures more completely, while mechanical and optical properties are not affected. Polymerization inhibitor H50614 was employed in Examples 1-5 and 7-10 and Example 12, and this component was not employed in Example 13. Although it is generally believed that the polymerization inhibitor component may affect or inhibit the curing of the silicone composition under the curing conditions of the present invention, it is compared by Table 1 and by Examples 1-5 and 7-10 and Example 13. It can be seen that the curing rates of Examples 1-5 and 7-10 were still much higher than in Example 13 even without the addition of H50614.

Furthermore, it can be seen from Figures 1 to 6 that the cured composition containing the ultraviolet absorber Ciba TINUVIN 384-2 remains good after aging for 24 hours at 150 ° C under long-term aging conditions such as high temperature accelerated aging test conditions. Light transmittance and UV absorption. Meanwhile, in the case of using the ultraviolet absorber Ciba TINUVIN 384-2, the use of the organic solubilizer can be omitted.

In addition, the polysiloxane composition comprising the ultraviolet absorber Ciba TINUVIN 384-2 according to formula (Z) is also significantly superior in transparency and ultraviolet absorption effect to the use of triazines (Example 6) and hindered amines ( Example 11) A composition of an ultraviolet absorber. Triazine-based UV absorbers are not very compatible with silicone resins. In order to improve compatibility, more solvents are needed, which causes the solvent to precipitate from the cured sample, resulting in low transmittance (see figure 3)). As shown in Fig. 6, the hindered amine-based ultraviolet absorber could not completely absorb the UV light, and the light transmittance and the ultraviolet absorption effect remained unchanged after the aging treatment.

Claims

A silicone composition comprising:

(A) an alkenyl polysiloxane component comprising or consisting essentially at least one of from 0 to 99.9%, based on the total weight of the polysiloxane A1 and the polysiloxane resin A2, having at least two per molecule a polysiloxane A1 bonded to the alkenyl group on the silicon precursor and 0.1 to 100% of at least one polysiloxane resin A2 having at least two alkenyl groups bonded to the silicon atom per molecule,

The silicone resin A2 described therein comprises or consists essentially of:

At least two different siloxane units selected from the group consisting of siloxane units M of the formula R 3 SiO 1/2 , siloxane units D of the formula R 2 SiO 2/2 , siloxane units T of the formula RSiO 3/2 And a siloxane unit Q of the formula SiO 4/2 , wherein R represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably a monovalent aliphatic or aromatic group of 1 to 12, more preferably 1 to 8 carbon atoms Hydrocarbyl group,

Wherein at least one of the siloxane units is a siloxane unit T or Q and at least one of the siloxane units M, D and T comprises an alkenyl group,

Provided that at least one of the silicone resins A2 is a silicone resin comprising at least one siloxane unit M (M Vi unit) having an alkenyl group;

(B) a hydrogen-containing polysiloxane component comprising or consisting essentially of at least one hydrogen-containing polysiloxane B1 having at least one silicon-hydrogen atom bonded to the same or different silicon atoms per molecule, or at least a hydrogen-containing polysiloxane resin B2 having at least one silicon hydrogen atom bonded to the same or different silicon atoms per molecule or a mixture of the two,

Provided that the hydrogen-containing polysiloxane component comprises a total of at least two of the silicon hydrogen atoms;

(C) an effective amount of at least one hydrosilylation reaction catalyst.
The silicone composition of claim 1 wherein In the polysiloxane resin A2, the ratio of the alkenyl group bonded to the unit M to the total alkenyl group content in the polysiloxane resin A2 should be more than 50%, preferably more than 60%, more preferably more than 80. %, most preferably greater than 90%.
The polysiloxane composition according to claim 1 or 2, wherein the content of the alkenyl group in the silicone resin A2 is 0.001 mol or more, preferably 0.01 based on 100 g of the polysiloxane resin A2. More than mol.
The polysiloxane composition according to any one of claims 1 to 3, wherein the polysiloxane resin of the alkenyl group-containing siloxane unit M (M Vi unit) is selected from the group consisting of M Vi Q, an organopolysiloxane resin of the formula MM Vi Q, the formula M Vi TQ and the formula M Vi DQ, and particularly preferably an organopolysiloxane resin selected from the group consisting of MM Vi Q.
The polysiloxane composition according to any one of claims 1 to 4, wherein the polysiloxane resin A2 has a weight average molecular weight of from 200 to 100,000, preferably from 200 to 50,000, more preferably A range of 500-30,000.
The polysiloxane composition according to any one of claims 1 to 5, wherein the polysiloxane A1 comprises:

(i) siloxane unit of formula (I-1)

among them

R x represents a C 2-12 , preferably C 2-6 alkenyl group, most preferably a vinyl or allyl group,

Z may represent, identically or differently, a monovalent hydrocarbon radical having from 1 to 30, preferably from 1 to 12, carbon atoms, preferably selected from C 1-8 alkyl, including alkyl optionally substituted by at least one halogen atom, And also preferably an aryl group selected from aryl groups, especially C 6-20 ,

a is 1 or 2, b is 0, 1 or 2 and the sum of a+b is 1, 2 or 3, and

(ii) optionally, other siloxane units of formula (I-2)

among them

Z has the meaning as described above and c is 0, 1, 2 or 3.
The polysiloxane composition according to any one of claims 1 to 6, wherein the composition further comprises an ultraviolet absorber component D.
The polysiloxane composition according to any one of claims 1 to 7, wherein the ultraviolet absorber component D comprises one or more benzotriazole compounds selected from the group consisting of:

among them

Y1 is -H, -Cl, -Br;

Y2 is -H, C 1 -C 12 alkyl, -Cl, C 1 -C 12 alkoxy, C 7 -C 9 phenylalkyl, -C n H 2n -COOX, wherein n is 0-4 and X is a C 1 -C 20 alkyl group, or a siloxane-substituted C 1 -C 12 alkyl group, a C 1 -C 12 alkoxy group, a C 7 -C 9 phenylalkyl group, and a -C n H 2n group -COOX;

Y3 is -H, C 1 -C 12 alkyl, C 1 -C 12 alkoxy, phenyl, -Cl, (C 1 -C 8 alkyl)phenyl, C 5 -C 6 cycloalkyl, C 2 -C 9 alkoxyacyl, carboxyethyl, C 7 -C 9 phenylalkyl, or siloxane-substituted C 1 -C 12 alkyl, C 1 -C 12 alkoxy, phenyl, (C 1 -C 8 alkyl)phenyl, C 5 -C 6 cycloalkyl, C 2 -C 9 alkoxyacyl, carboxyethyl, C 7 -C 9 phenylalkyl.
The polysiloxane composition according to any one of claims 1 to 8, wherein the ultraviolet absorber component D comprises 3-(2'H-benzotriazole)-5-(1) ',1'-Dimethylethyl)-4-hydroxy-phenylpropyl octyl ester.
The polysiloxane composition according to any one of claims 1 to 9, wherein the total content of the components A and B is more than 50% by weight, preferably more than 60% by weight, based on the total component. More preferably, it is 80% by weight or more.
A silicone composition comprising:

(A) an alkenyl polysiloxane component comprising or consisting essentially at least one of from 0 to 99.9% by weight, based on the total weight of the polysiloxane A1 and the silicone resin A2, having at least two per molecule a polysiloxane A1 bonded to the alkenyl group on the silicon precursor and 0.1 to 100% by weight of at least one polysiloxane resin A2 having at least two alkenyl groups bonded to the silicon atom per molecule,

The silicone resin A2 described therein comprises or consists essentially of:

At least two different siloxane units selected from the group consisting of siloxane units M of the formula R 3 SiO 1/2 , siloxane units D of the formula R 2 SiO 2/2 , siloxane units T of the formula RSiO 3/2 And a siloxane unit Q of the formula SiO 4/2 , wherein R represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably a monovalent aliphatic or aromatic group of 1 to 12, more preferably 1 to 8 carbon atoms Hydrocarbyl group,

And at least one of the siloxane units is a siloxane unit T or Q, and at least one of the siloxane units M, D and T comprises an alkenyl group;

(B) a hydrogen-containing polysiloxane component comprising or substantially comprising

At least one hydrogen-containing polysiloxane B1 having at least one silicon hydrogen atom bonded to the same or different silicon atoms per molecule, or at least one having at least one bond per molecule a hydrogen-containing polysiloxane resin B2 of a silicon hydrogen atom attached to the same or different silicon atoms or a mixture of the two,

Provided that the hydrogen-containing polysiloxane component comprises a total of at least two of said silicon hydrogen atoms;

(C) an effective amount of at least one hydrosilylation reaction catalyst;

(D) UV absorber component D comprising one or more benzotriazole compounds selected from formula Z:

among them

Y1 is -H, -Cl, -Br;

Y2 is -H, C 1 -C 12 alkyl, -Cl, C 1 -C 12 alkoxy, C 7 -C 9 phenylalkyl, -C n H 2n -COOX, wherein n is 0-4 and X is a C 1 -C 20 alkyl group, or a siloxane-substituted C 1 -C 12 alkyl group, a C 1 -C 12 alkoxy group, a C 7 -C 9 phenylalkyl group, and a -C n H 2n group -COOX;

Y3 is -H, C 1 -C 12 alkyl, C 1 -C 12 alkoxy, phenyl, -Cl, (C 1 -C 8 alkyl)phenyl, C 5 -C 6 cycloalkyl, C 2 -C 9 alkoxyacyl, carboxyethyl, C 7 -C 9 phenylalkyl, or siloxane-substituted C 1 -C 12 alkyl, C 1 -C 12 alkoxy, phenyl, (C 1 -C 8 alkyl)phenyl, C 5 -C 6 cycloalkyl, C 2 -C 9 alkoxyacyl, carboxyethyl, C 7 -C 9 phenylalkyl.
The polysiloxane composition according to claim 11 wherein

Y1 represents H;

Y2 represents C 3 -C 12 alkyl, C 7 -C 9 phenylalkyl, -C n H 2n -COOX, wherein n represents 1-3 and/or X represents a C 1 -C 12 alkyl group, or silicon Oxyalkyl-substituted C 1 -C 12 alkyl; more preferably Y2 represents C 3 -C 12 alkyl, siloxane-substituted C 1 -C 12 alkyl or -C n H 2n -COOX, wherein n represents 1-3 and/or X represents a C 3 -C 12 alkyl group; and/or

Y3 represents C 1 -C 4 alkoxy, phenyl, -C1 or C 1 -C 12 alkyl, siloxane-substituted C 1 -C 12 alkyl, more preferably C 1 -C 8 alkyl and silicon Oxyalkyl-substituted C 1 -C 12 alkyl.
The polysiloxane composition according to claim 11 or 12, wherein the ultraviolet absorber component D comprises one or more selected from the group consisting of 2-(2'-hydroxy-3', 5'-di-tert-amylphenyl)benzotriazole, 2-(2'-hydroxy-3'-(bis(trimethylsilyloxy)methylsilylisobutyl)-5'-hexyl) Benzotriazole and 3-(2'H-benzotriazole)-5-(1',1'-dimethylethyl)-4-hydroxy-phenylpropyl octyl ester.
The polysiloxane composition according to any one of claims 11 to 13, wherein the benzotriazole compound is 3-(2'H-benzotriazole)-5-(1', 1'-Dimethylethyl)-4-hydroxy-phenylpropyl octyl ester.
The polysiloxane composition according to any one of claims 11 to 14, wherein at least one of the silicone resins A2 is a siloxane unit M comprising at least one alkenyl group ( Silicone resin of M Vi unit).
The polysiloxane composition according to any one of claims 11 to 15, wherein in the polysiloxane resin A2, the content of the alkenyl group bonded to the unit M accounts for the polysilicon The proportion of all alkenyl groups in the oxyalkylene resin A2 should be greater than 50%, preferably greater than 60%, more preferably greater than 80%, and most preferably greater than 90%.
The polysiloxane composition according to any one of claims 11 to 16, wherein the content of the alkenyl group in the silicone resin A2 is relative to 100 g of polysilicon. The oxyalkylene resin A2 is 0.001 mol or more, preferably 0.01 mol or more.
The polysiloxane composition according to any one of claims 15 to 17, wherein the polysiloxane resin of the alkenyl group-containing siloxane unit M (M Vi unit) is selected from the group consisting of M Vi Q, an organopolysiloxane resin of the formula MM Vi Q, the formula M Vi TQ and the formula M Vi DQ, and particularly preferably an organopolysiloxane resin selected from the group consisting of MM Vi Q.
An element, in particular an optical element, preferably a Fresnel lens, characterized in that it comprises a polysiloxane composition according to any one of claims 1 to 18.