WO2007060125A1

WO2007060125A1 - Reactive silicon oxide flakes

Info

Publication number: WO2007060125A1
Application number: PCT/EP2006/068512
Authority: WO
Inventors: Holger Hoppe; Ulrich Schubert; Philipp Heinz
Original assignee: Ciba Spezialitaetenchemie Holding AG; Ciba SC Holding AG
Current assignee: BASF Schweiz AG
Priority date: 2005-11-25
Filing date: 2006-11-15
Publication date: 2007-05-31
Anticipated expiration: 2008-05-25

Abstract

The present invention is directed to a product, obtainable by reacting a SiOy flake, or a material comprising a SiOy layer with 0.70 ≤ y ≤ 1.95, especially 0.70 ≤ y ≤1.80, very especially 1.0 ≤ y ≤ 1.8 with a protic substance, such as water, or a protic organic solvent to generate Si-H, Si-H2 and/or a-Si:H groups and reacting the obtained intermediate with a compound having functional groups that can react with Si-H, Si-H2 and/or a-Si:H groups and a process for their production. By using the Si-H group as anchor on the surface for organic compounds hazardous reducing agents like lithium aluminum hydride, borane or hydrogen can be avoided for reductive grafting methods. Organic and inorganic compounds, such as, for example, colorants, or additives, such as, for example, UV absorbers, or photoinitiators, or polymers can immobilized. The modified flakes can be used in coatings, plastics, fibres etc.

Description

Reactive Silicon Oxide Flakes

The present invention is directed to a product, obtainable by reacting a SiO_y flake, or a material comprising a SiO_y layer with 0.70 < y < 1.95, especially 0.70 < y < 1.80, very especially 1.0 < y < 1.8 with a protic substance, such as water, or a protic organic solvent to generate Si-H, Si-H₂ and/or a-Si:H groups and reacting the obtained intermediate with a compound having functional groups that can react with Si-H, Si-H₂ and/or a-Si:H groups and a process for their production. By using the Si-H group as anchor on the surface for organic compounds hazardous reducing agents like lithium aluminum hydride, borane or hydrogen can be avoided for reductive grafting methods. Organic and inorganic compounds, such as, for example, colorants, or additives, such as, for example, UV absorbers, or photoinitiators, or polymers can be immobilized. The modified flakes, i.e. the product can be used in coatings, plastics, fibres etc.

WO03/068868 (and WO03/106569) describes a process for the production of SiO_y flakes (0.95 < y < 1.8): NaCI, followed successively by a layer of silicon suboxide (SiO_y) are vapor- deposited onto a carrier, which may be a continuous metal belt, passing by way of the vaporisers under a vacuum of < 0.5 Pa.

According to WO04/065295 porous SiO_z flakes (0.70 < y < 2.0) are produced in the following manner: NaCI, followed successively by a layer of silicon suboxide (SiO_y) and NaCI, are vapor-deposited onto a carrier, which may be a continuous metal belt, passing by way of the vaporisers under a vacuum of < 0.5 Pa. The mixed layer of silicon suboxide (SiO_y) and NaCI is vapor-deposited by two distinct vaporizers, wherein the separating agent is contained in the mixed layer in an amount of 1 to 60 % by weight based on the total weight of the mixed layer. The carrier is immersed in water. With mechanical assistance, the NaCI rapidly dissolves in water and the product layer breaks up into flakes, which are then present in water in the form of a suspension.

Surprisingly, it has been found that by immersing SiO_y in water or a protic organic solvent Si- H, Si-H₂ and/or a-Si:H groups are generated. Said Si-H, Si-H₂ and/or a-Si:H groups can be used to provide chemically modified SiCy

Accordingly, he present invention is directed to a product, obtainable by reacting a SiO_y flake, or a material comprising a SiO_y layer with 0.70 < y < 1.95, especially 0.70 < y < 1.80, very especially 1.0 < y < 1.8 with a protic substance, such as water, or a protic organic solvent to generate Si-H, Si-H₂ and/or a-Si:H groups and reacting the obtained intermediate (silicon oxide having Si-H, Si-H₂ and/or a-Si:H groups) with a compound having functional groups that can react with Si-H, Si-H₂ and/or a-Si:H groups.

By using a separating agent, which is dissolvable in water, or a protic organic solvent (separating agent I), and optionally a separating agent, which is dissolvable in an inert solvent, which does not react with the SiO_y (separating agent II), the following products are available: a) silicon oxide flakes having Si-H, Si-H₂ and/or a-Si:H (hydrogenated amorphous silicon) groups on their surface, b) porous silicon oxide flakes having Si-H, Si-H₂ and/or a-Si:H groups on their surface and in their pores, as well as c) porous silicon oxide flakes having Si-H, Si-H₂ and/or a-Si:H groups only on their surface, or only in their pores.

The term "SiO_y with 0.70 < y < 1.95" means that the molar ratio of oxygen to silicon at the average value of the silicon oxide substrate is from 0.70 to 1.95. The composition of the silicon oxide substrate can be determined by ESCA (electron spectroscopy for chemical analysis). The stoichiometry of silicon and oxygen of the silicon oxide substrate can be determined by RBS (Rutherford-Backscattering).

The plate-like (plane-parallel) silicon oxide structures (silicon oxide flakes), hereinafter referred to as "reactive silicon oxide flakes", used according to the present invention have a length of from 1 μm to 5 mm, a width of from 1 μm to 2 mm, and a thickness of from 20 nm to 1.5 μm, and a ratio of length to thickness of at least 2 : 1 , the particles having two substantially parallel faces, the distance between which is the shortest axis of the particles (thickness). The porous reactive silicon oxide flakes are mesoporous materials, i.e. have pore widths of ca. 1 to ca. 50 nm, especially 2 to 20 nm. The pores are randomly inter-connected in a three-dimensional way. So, when used as a support, the passage blockage, which frequently occurs in SiO₂ flakes having a two-dimensional arrangement of pores can be prevented. The specific surface area of the porous reactive silicon oxide flakes depends on the porosity and ranges from ca. 400 m²/g to more than 1000 m²/g. Preferably, the porous reactive silicon oxide flakes have a specific surface area of greater than 500 m²/g, especially greater than 600 m²/g. The BET specific surface area is determined according to DIN 66131 or DIN 66132 (R. Haul und G. Dϋmbgen, Chem.-lng.-Techn. 32 (1960) 349 and 35 (1063) 586) using the Brunauer-Emmet-Teller method (J. Am. Chem. Soc. 60 (1938) 309). The reactive silicon oxide flakes are not of a uniform shape. Nevertheless, for purposes of brevity, the flakes will be referred to as having a "diameter." The reactive silicon oxide flakes flakes have a plane-parallelism and a defined thickness in the range of ± 10 %, especially ± 5 % of the average thickness. The reactive silicon oxide flakes have a thickness of from 20 to

2000 nm, especially from 100 to 500 nm. It is presently preferred that the diameter of the flakes is in a preferred range of about 1-60 μm with a more preferred range of about 5-40 μm and a most preferred range of about 5-20 μm. Thus, the aspect ratio of the flakes of the present invention is in a preferred range of about 2.5 to 625 with a more preferred range of about 50 to 250.

The processes for the production of a) silicon oxide flakes having Si-H, Si-H₂ and/or a-Si:H groups on their surface, b) porous silicon oxide flakes having Si-H, Si-H₂ and/or a-Si:H groups on their surface and in their pores, as well as c) porous silicon oxide flakes having Si-H, Si-H₂ and/or a-Si:H groups only on their surface, or only in their pores is described in more detail below:

Variant a) The silicon oxide flakes having Si-H, Si-H₂ and/or a-Si:H groups on their surface are obtainable by a process comprising the steps of: a) vapor-deposition of a separating agent I onto a carrier to produce a separating agent layer, b) the vapor-deposition of SiO_y onto the separating agent layer (a), c) the separation of SiO_y from the separating agent I, wherein 0.70 < y < 1.80, by dissolution in water, or a protic organic solvent, and d) reacting the silicon oxide flakes obtained in step c) and having Si-H, Si-H₂ and/or a-Si:H groups with a compound having functional groups that can react with the Si-H, Si-H₂ and/or a- Si:H groups.

Variant b)

The porous silicon oxide flakes having Si-H, Si-H₂ and/or a-Si:H groups on their surface and in their pores are obtainable by a process comprising the steps of: a) vapor-deposition of a separating agent I onto a carrier to produce a separating agent layer, b) the simultaneous vapor-deposition of SiO_y and the separating agent I onto the separating agent layer (a), c) the separation of SiO_y from the separating agent I, wherein 0.70 < y < 1.95, by dissolution in water, or a protic organic solvent, and d) reacting the silicon oxideflakes obtained in step c) and having Si-H, Si-H₂ and/or a-Si:H groups with a compound having functional groups that can react with the Si-H, Si-H₂ and/or a-Si:H groups.

Variant c) The porous silicon oxide flakes having Si-H, Si-H₂ and/or a-Si:H groups only on their surface are obtainable by a process comprising the steps of: a) vapor-deposition of a separating agent I onto a carrier to produce a separating agent layer, b) the simultaneous vapor-deposition of SiO_y and a separating agent II, which is dissolvable in an inert organic solvent, but not in water, or the protic organic solvent, onto the separating agent layer (a), c) the separation of SiO_y from the separating agent I, wherein 0.70 < y < 1.95, by dissolution in water, or the protic organic solvent, and d) reacting the silicon oxideflakes obtained in step c) and having Si-H, Si-H₂ and/or a-Si:H groups with a compound having functional groups that can react with the Si-H, Si-H₂ and/or a-Si:H groups, and

(e) the dissolution of the separating agent Il in the inert solvent.

By dissolution of the separating agent Il in the inert solvent silicon oxide flakes having reactive centres, i.e. Si-Si groups that can be cleaved, in their pores, are obtained, which can be used to chemically bond compounds having functional groups, especially organic compounds having functional groups to the silicon oxide flakes. For more details reference is made to WO06/010720.

The porous silicon oxide flakes having Si-H, Si-H₂ and/or a-Si:H groups only in their pores are obtainable by a process comprising the steps of: a) vapor-deposition of a separating agent Il onto a carrier to produce a separating agent layer, b) the simultaneous vapor-deposition of SiO_y and a separating agent I onto the separating agent layer (a), b') the separation of SiO_y from the separating agent II, wherein 0.70 < y < 1.95, by dissolution in the inert solvent, b") the removal of the reactive centres obtained in step b'), c) the dissolution of the separating agent I in water, or a protic organic solvent, and d) reacting the silicon oxideflakes obtained in step c) and having Si-H, Si-H₂ and/or a-Si:H groups with a compound having functional groups that can react with the Si-H, Si-H₂ and/or a-Si:H groups.

The separating agent I is dissolvable in water, or the protic organic solvent, but not in the inert solvent.

In one preferred embodiment of the present invention separating agent I is an inorganic salt soluble in water and vaporisable in vacuo, such as, for example, sodium chloride, potassium chloride, lithium chloride, sodium fluoride, potassium fluoride, lithium fluoride, calcium fluoride, sodium aluminium fluoride and disodium tetraborate, or mixtures thereof. The solvent, which is used for its dissolution is water.

The separating agent Il is dissolvable in the inert solvent, but not in water, or the protic organic solvent.

The separating agent Il is an organic substance soluble in organic solvents, is inert against the reactive SiO_y flakes and vaporisable in vacuo, such as anthracene, anthraquinone, acetamidophenol, acetylsalicylic acid, camphoric anhydride, benzimidazole, bis(4- hydroxyphenyl)sulfone, dihydroxyanthraquinone, hydantoin, phenolphthalein, phenothiazine, tetraphenylmethane, triphenylene, triphenylmethanol or a mixture of at least two of those substances.

Suitable inert solvents are, for example, ethers, in particular those having 2 to 8 carbon atoms in the molecule, such as, for example, diethyl ether, methyl ethyl ether, di-n-propyl ether, diisopropyl ether, methyl n-butyl ether, methyl tert-butyl ether, ethyl n-propyl ether, din-butyl ether, tetrahydrofuran, 1 ,4-dioxane, 1 ,2-dimethoxyethane, bis-β-methoxyethyl ether; aliphatic hydrocarbons, such as, for example, hexane, heptane, low- and high-boiling petroleum ethers; cycloaliphatic hydrocarbons, such as, for example, cyclohexane, methylcyclohexane, tetralin, decalin; aromatic hydrocarbons, such as, for example, benzene, toluene, o-, m- and p-xylene, ethylbenzene. Nitriles, such as, for example, acetonitrile; amides, such as, for example, dimethylformamide, dimethylacetamide, N-methylpyrrolidone; hexamethylphosphoric triamide; and sulfoxides, such as, for example, dimethyl sulfoxide are less preferred. Mixtures of various solvents can also be used.

The SiOy flakes having Si-H, Si-H₂ and/or a-Si:H groups can be used to chemically bond compounds having functional groups, especially organic compounds having functional groups to the SiO_y flakes. The reaction of the Si-H, Si-H₂ and/or a-Si:H with the compounds having functional groups results in the formation of chemical bonds between the compounds

(Si-|compound|) and the SiO_y flakes.

A functional group is any group, which can react with the Si-H, Si-H₂ and/or a-Si:H groups to form a chemical bond:

-SiH + HX »^■ -Si-X + H₂

I I

Examples of HX are listed below, but not limited thereto:

R¹OH, R¹SH, R¹R²C(=N-OH), R¹R²NOH, R¹R³NH, NHR³C(=O)R², or R¹C(=O)OH, wherein R¹ and R² are independently of each other an organic group, and R³ is hydrogen, or an organic group.

Preferably, the compound having the functional group is not ethanol, 1-methyl-2-pyrrolidone (NMP), or water. In a preferred embodiment of the present invention the protic substance is different from the compounds having functional groups.

In case of the dehydrohalogenation Si-C coupling reaction a mixture of, for example, an alkyl halide and the SiO_y flakes having Si-H, Si-H₂ and/or a-Si:H groups is heated in the presence of tertiary amine or organic salts (quaternary organoammonium and organophosphonium halides) as catalyst.

The reaction of the SiO_y flakes having Si-H, Si-H₂ and/or a-Si:H groups with primary or secondary hydroxyl groups to form silyl ethers can be done, for example, in a solvent, such as dimethylformamide, tetrahydrofurane, or acetonitrile, in the presence of a catalyst, such as caesium fluoride/imidazole.

In a preferred embodiment of the present invention HX is R¹OH, especially R¹CH₂OH.

R¹CH₂OH can, for example, be derived from a polymer additive by modifying it with a -CH₂OH group, or can be a polymer additive, which bears a -CH₂OH group. Such polymer additives can be selected from the group consisting of light stabilizers, heat stabilizers, metal deactivators, processing stabilizers, acid scavengers, anti-blocking agents, anti-fogging agents, antistatic agents, flame retardants, hydrophilic/hydrophobic surface modifiers, IR-reflectors, IR-absorbers, nucleating agents, scratch resistance additives and thermally conductive additives.

In addition, R¹CH₂OH can be derived from a UV absorber, especially for the protection of skin and hair, or it can be a fluorescent whitening agent.

In addition, R¹CH₂OH can, for example, be derived from an organic colorant by modifying it with a -CH₂OH group, or can be an organic colorant, which bears a -CH₂OH group. The organic colorant can be or can be derived from a dye, or a pigment.

As an example of the different dye classes, reference may be made to the Colour Index; Colour Index, Third Edition, 1970/1971 : Acid Dyes, Volume 1 , pages 1001 to 1562; Basic Dyes, Volume 1 , pages 1607 to 1688; Direct Dyes, Volume 2, pages 2005 to 2478; Disperse Dyes, Volume 2, pages 2479 to 2743; Natural Dyes, Volume 3, pages 3225 to 3256; Pigments, Volume 3, pages 3267 to 3390; Reactive Dyes, Volume 3, pages 3391 to 3560; Solvent Dyes, Volume 3, pages 3563 to 3648; Vat Dyes, Volume 3, pages 3719 to 3844.

The organic colorant can be derived from pigments, such as 1-aminoanthraquinone, anthraquinone, anthrapyrimidine, azo, azomethine, benzodifuranone, quinacridone, quinacridone-quinone, quinophthalone, diketopyrrolopyrrole, dioxazine, flavanthrone, indanthrone, indigo, isoindoline, isoindolinone, isoviolanthrone, perinone, perylene, phthalocyanine, pyranthrone or thioindigo. Examples of such chromophores are described, for example, in W. Herbst, K. Hunger, lndustrielle Organische Pigmente, 2^nd completely revised edition, VCH 1995.

The organic colorant can be a fluorescent organic colorant which is, for example, selected from coumarins, benzocoumarins, xanthenes, benzo[a]xanthenes, benzo[b]xanthenes, benzo[c]xanthenes, phenoxazines, benzo[a]phenoxazines, benzo[b]phenoxazines and benzo[c]phenoxazines, napthalimides, naphtholactams, azlactones, methines, oxazines and thiazines, diketopyrrolopyrroles, perylenes, quinacridones, benzoxanthenes, thio-epindolines, lactamimides, diphenylmaleimides, acetoacetamides, imidazothiazines, benzanthrones, perylenmonoimides, perylenes, phthalimides, benzotriazoles, pyrimidines, pyrazines, and triazines.

Suitable examples are the diketopyrrolopyrroles described in WO04/009710 of the general formula:

'

in which R₂i and R₂₂ are independently of one another hydrogen, CrCi₈alkyl, d-Ci₈alkyl which is interrupted one or more times by O or S, C₇-C-i₂aralkyl or a group of the formula

O -CO-R₁₅ ' in which R₁₅ is CrCi₈alkyl,

R₂3 and R₂₄ independently of one another are a group of formula

-X₁-X₂-Xs, wherein Xi is -S-, -SO₂NH- Or -NH-, X₂ is a CrCi₈alkylene group, and X₃ is -OH; or

. wherein

R3₁ and R₃₂ are independently of each other a radical of the formula

-X₂-X₃, wherein X₂ is Ci-Ci₈alkylene and X₃ is -OH, R₃3 and R3₄ independently of one another are Ci-Ciβalkyl, C-i-C-iβalkoxy, -NR₁₆Ri7, -CONHR₁₈, COOR₁9, -SO₂NH-R₂O, CrCi₈alkoxycarbonyl, Ci-Ci₈alkylaminocarbonyl, wherein R₁6, Ri7, Ri₈, Rig and R₂₀ are CrCiβalkyl. Examples of such compounds are shown below:

wherein n2 is O to 18; or ■ wherein n1 is 1 to 18.

The reactive silicon oxide flakes can be rendered hydrophobic by reacting them with an alcohol R³⁰OH, or R³⁰CI, wherein R³⁰ represents a substituted or unsubstituted C_rC₂₀alkyl group. Specific examples of R³⁰ include methyl, ethyl, especially n-propyl, isopropyl, n-butyl, sec. -butyl, isobutyl, tert. -butyl, n-pentyl, 2-pentyl, 3-pentyl, 2,2-dimethylpropyl, n-hexyl, n- heptyl, n-octyl, 1 ,1 ,3,3-tetramethylbutyl and 2-ethylhexyl, n-nonyl, decyl, undecyl, dodecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, eicosyl, heneicosyl, docosyl, tetracosyl or pentacosyl, preferably CrC₈alkyl such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec. -butyl, isobutyl, tert. -butyl, n-pentyl, 2-pentyl, 3-pentyl, 2,2-dimethyl-propyl, n- hexyl, n-heptyl, n-octyl, 1 ,1 ,3,3-tetramethylbutyl and 2-ethylhexyl. An example of a substituted Ci-C₂oalkyl group is a "fluoroalkyl" group. The term "fluoroalkyl" means groups given by partially or wholly substituting the above-mentioned alkyl group with fluorine, such as trifluoromethyl, trifluoropropyl, especially 3,3,3-trifluoro-n-propyl, 2,2,2,2',2',2'- hexafluoroisopropyl and heptadecafluorodecyl. In a further aspect of the present invention the pores of the reactive silicon oxide flakes can first be filled, for example, with a fluorescent dye and then be rendered hydrophobic by reacting them with an alcohol R³⁰OH.

In addition, the reactive silicon oxide flakes can be used to prepare activatable flakes:

PG-LS-|siϊicon oxide flake|, wherein PG is an activatable group, LS is a linkage or spacer group, and silicon oxide flake is a silicon oxide flake derived from the reactive silicon oxide flake.

A linkage or spacer group joins the activable group to the |silicon oxide flake|. It is preferred that the linkage or spacer group includes a hydrocarbon chain and a -O-, or -NH- linkage.

PG can be activated by heat or electromagnetic radiation from microwaves to γ-radiation.

Photoinitiators, from which the activatable group can be derived, are commercially available, e.g. under the trademark IRGACURE (Ciba Specialty Chemicals), ESACURE (Fratelli Lamberti), LUCIRIN (BASF), VICURE (Stauffer), GENOCURE, QUANTACURE (Rahn/Great Lakes), SPEEDCURE (Lambsons), KAYACURE (Nippon Kayaku), CYRACURE (Union Carbide Corp.), DoubleCure (Double Bond), EBECRYL P (UCB), FIRSTCURE (First Chemical), etc..

Examples of preferred photoinitiators are given below:

(wherein R = H or CH₃),

(Radcure '86, Conference Proceedings, 4-43 to

4-54 by W. Baumer et a/.),

' ^{UVe Cryl P36 frOm UCB}' ^{and SOme}

copolymerisable unsaturated tertiary amines (Uvecryl P101 , Uvecryl P104, Uvecryl P105, Uvecryl P1 15 from UCB Radcure Specialties) or copolymerisable aminoacrylates (Photomer 4116 and Photomer 4182 from Ackros; Laromer LR8812 from BASF; CN381 and CN386 from Cray Valley). The compounds are bonded to the silicon oxide flakes by a hydrosilylation reaction, wherein, for example, the following product is obtained:

Further examples of suitable photoinitiators are α-hydroxy ketones, α-alkoxyketones or α- aminoketones of the formula (II), and phenylglyoxalates of the formula (III):

²³ (II), wherein

R₂O is hydrogen or Ci-Ci8-alkoxy; R₂i is hydrogen, C_rCi₈-alkyl, C_rCi₂hydroxyalkyl ,C_rCi₈-alkoxy, -(OCH₂CH₂)_Y-OR₂₅, morpholino, di(Ci-C₂₀alkyl)amino, H(Ci-C₂₀alkyl)amino, NH₂, OH, CrCi₈alkyl-S-, a group

H₂C=CH-, H₂C=C(CH₃)- , G₁ -[- CH₂ - c -J₇ G₂ , R,, - C - C

R₂₂ is OH, C_rCi6-alkoxy, morpholino, di(C_rC₄alkyl)amino or -O(CH₂CH₂O)_y-Ci-Ci₆-alkyl;

R₂₃ and R₂₄ independently of one another are hydrogen, d-C₆-alkyl, CrCi₆-alkoxy or -O(CH₂CH₂O)_y-Ci-Ci₆-alkyl; or unsubstituted phenyl or benzyl; or phenyl or benzyl substituted by CrCi₂-alkyl; or R₂3 and R₂₄ together with the carbon atom to which they are attached form a cyclohexyl ring;

O O CH,

Il I l I ³

R₂₅ is hydrogen, — C-CH=CH₂ or — C-C=CH₂ ;

a, b and c are 1-3; x is 2-10; y is 1-20;

G₁ and G₂ independently of one another are end groups of the polymeric structure, preferably hydrogen or methyl; G₃ is O, CH₂ Or CH-OH; with the proviso that R₂₁ (H₂C=CH-, H₂C=C(CH₃)-) and/or R₂₅ (H₂C=CH-, H₂C=C(CH₃)-) are an unsaturated group,

(HI), wherein

Z is O, S or NR₅₄;

R₅₀ is hydrogen, CrC₅₀alkyl, C₂-C₂₄alkenyl, C₃-C₂₅cycloalkyl; C₂-C₂₅₀alkyl interrupted by one or more Z₂; C₂-C₂₄alkenyl interrupted by one or more Z₂; C₃-C₂₅cycloalkyl interrupted by one or more Z₂; wherein said radicals CrC₅₀alkyl, C₂-C₂₄alkenyl, C₃-C₂₅cycloalkyl; C₂-C₂₅₀alkyl interrupted by one or more Z₂; C₂-C₂₄alkenyl interrupted by one or more Z₂; C₃-C₂₅cycloalkyl interrupted by one or more Z₂;optionally are substituted by one or more A₂; or R₅₀ is phenyl, optionally substituted by A₁; or, when Z is NR₅₄, R₅₄ and R₅₀ together with the N-atom optionally form a ring,

^64 ^65 O R₆4 ^65

A₂ is -Z₁-C=C-R₆₆ , -Z₁-C-C=C-R₆₆ , OR₅₈, SR₅₈, NR₅₉R₆₀, halogen; or A₂ is unsubstituted phenyl, or phenyl substituted by one or more CrC₂₄alkyl, C₃-C₂₅cycloalkyl, C₂- C₂₄alkenyl, C₂-C₂₄alkinyl, phenyl, OR₅₈, SR₅₈, COR₅₈, COOR₅₈, OCOR₅₈, CON₅₉R₆₀,

R i 65

OCONR₅₉R₆₀, R, 66

A₁ is CrC₂₄alkyl, C₂-C₂₄alkyl interrupted by one or more Z₂; C₂-C₂₄alkenyl, C₂-C₂₄alkenyl interrupted by one or more Z₂; C₃-C₂₅cycloalkyl; C₃-C₂₅cycloalkyl interrupted by one or more Z₂; wherein said radicals CrC₂₄alkyl, C₂-C₂₄alkyl interrupted by one or more Z₂, C₂- C₂₄alkenyl; C₂-C₂₄alkenyl interrupted by one or more Z₂; C₃-C₂₅cycloalkyl; and C₃- C₂₅cycloalkyl interrupted by one or more Z₂; optionally are substituted by one or more C₂- C₂₄alkinyl, phenyl, OR₅₈, SR₅₈, -COR₅₈, COOR₅₈, -Z₁-C=C-R₆₆ and/or

-Z₁-C-C=C-R₆₆ ;

Or A₁ is -Z₁-C=C-R₆₆ , -Z₁-C-C=C-R₆₆ , OR₅₈, SR₅₈, NR₅₉R₆₀, unsubstituted phenyl; or A₁ is phenyl substituted by one or more C-ι-C₂₄alkyl, C₂-C₂₄alkenyl, C₃-C₂₅cycloalkyl, C₂- C₂₄alkinyl, phenyl, OR₅₈, SR₅₈, COR₅₈, COOR₅₈, OCOR₅₈, CON₅₉R₆₀, OCONR₅₉R₆₀,

^64 ^65 O R₆4 ^65

— Z₁-C=C-R₆₆ and/or — Z₁-C-C=C-R₆₆ ;

R5₁, R5₂ and R₅₃ independently of one another are hydrogen, halogen, CN, CrC₂₄alkyl, C₂- C₂₄alkyl interrupted by one or more Z₂; C₂-C₂₄alkenyl, C₂-C₂₄alkenyl interrupted by one or more Z₂; C₃-C₂₅cycloalkyl; C₃-C₂₅cycloalkyl interrupted by one or more Z₂; wherein said radicals CrC₂₄alkyl, C₂-C₂₄alkyl interrupted by one or more Z₂, C₂-C₂₄alkenyl, C₂-C₂₄alkenyl interrupted by one or more Z₂, C₃-C₂₅cycloalkyl, and C₃-C₂₅cycloalkyl interrupted by one or more Z₂; optionally are substituted by one or more C₂-C₂₄alkinyl, phenyl, halogen, OR₅₈,

^64 ^65

SR₅₈, NR₅₉R₆₀, COR₅₈, COOR₅₈, OCOR₅₈, N(R₅₄)COR₅₈, CON(R₅₄)R₅₈, -Z₁-C=C-R₆₆

and/or — Z₁-C-C — C-R₆₆ ;

or R₅₁, R₅₂ and R₅₃ are -Z₁-

OR₅₈, SR₅₈, NR₅₉R₆₀, COR₅₈, COOR₅₈, OCOR₅₈, N(R₅₄)COR₅₈, CON(R₅₄)R₅₈; or are unsubstituted phenyl, or phenyl substituted by one or more OR₅₈, SR₅₈, NR₅₉R₆₀, COR₅₈, COOR₅₈, OCOR₅₈, N(R₅₄)COR₅₈, CONR₅₉R₆₀, OCONR₅₉R₆₀, C_rC₂₄alkyl, C₂-C₂₄alkenyl, C₃-

^64 ^65 O ^64 ^65

C₂₅cycloalkyl, C₂-C₂₄alkinyl, phenyl, -Z₁-C=C-R₆₆ and/or -Z₁-C-C=C-R₆₆ ; or R₅₁ and R₅₂ together form CrC₆alkylene or R₅₁ and R₅₂ together form a benzene ring that is condensed to the phenyl ring to which they are attached;

R₅₄ has one of the meanings as given for R₅₀, or R₅₄ is — Z₁-C-C — C-R₆₆ ; Z₁ is a direct bond, O, S or NR₆₁; Z₂ is O, S, NR₆₁, CO, COO, OCO, CONR₆₁, NR₆₁CO, OCONR₆₁, NR₆₁COO, NR₆₁CONR₆₂,

SO, SO₂, CR₆₁=CR₆₂, C≡C , N=C-R₆₁, R₆₁C=N, -CH₂— <f 7-CH₂- phenylene; or phenylene

substituted by A₁;

R55, R56 and R₅₇ independently of one another have the same meanings as given for R₅₁, R₅₂ and R₅₃;

R₅₈, R₅₉ and R₆₀ independently of one another are hydrogen, CrC₂₄alkyl; C₂-C₂₄alkyl interrupted by one or more Z₂; C₂-C₂₄alkenyl; C₂-C₂₄alkenyl interrupted by one or more Z₂; C₃-C₂₅cycloalkyl; C₃-C₂₅cycloalkyl interrupted by one or more Z₂; wherein said radicals C₁- C₂₄alkyl; C₂-C₂₄alkyl interrupted by one or more Z₂; C₂-C₂₄alkenyl; C₂-C₂₄alkenyl interrupted by one or more Z₂; C₃-C₂₅cycloalkyl; and C₃-C₂₅cycloalkyl interrupted by one or more Z₂; optionally are substituted by one or more C₂-C₂₄alkinyl, phenyl, halogen, CN, OR₆₁, SR₆₁,

COR₆₁, COOR₆₁, -Z₁-

and/or .

or R₅₈, R₅9 and R₆₀ independently of one another are unsubstituted phenyl or phenyl substituted by one or more COR₆₁, COOR₆₁, OCOR₆₁, CONR₆₂R₆₃, OCONR₆₂R₆₃, C₁-

^64 ^65 C₂₄alkyl, C₂-C₂₄alkenyl, C₃-C₂₅cycloalkyl, C₂-C₂₄alkinyl, phenyl, OR₆₁, SR₆₁, — Z₁-C=C-R₆₆

O ^64 ^65 and/or -Z₁-C-C=C-R₆₆ ; or R₅₈, R₅g and R₆₀ independently of one another are phenyl-C-ι-C₄-alkyl substituted by one or more COR₆₁, COOR₆₁, OCOR₆₁, CONR₆₂R₆₃, OCONR₆₂R₆₃, C_rC₂₄alkyl, C₃-C₂₅cycloalkyl,

^64 ^65

C₂-C₂₄alkenyl, C₂-C₂₄alkinyl, phenyl, OR₆₁, SR₆₁, — Z₁-C=C-R₆₆ and/or

O I l R 1 , ₆00₄44 i 65 -Z₁-C-C=C-R₆₆ ;

R₆₁, R₆₂ and R₆₃ independently of one another are hydrogen, phenyl, CrC₂₄alkyl; C₂- C₂₄alkyl, interrupted by one or more Z₃; C₂-C₂₄alkenyl; C₂-C₂₄alkenyl interrupted by one or more Z₃; C₃-C₂₅cycloalkyl; C₃-C₂₅cycloalkyl interrupted by one or more Z₃; wherein said radicals phenyl, CrC₂₄alkyl; C₂-C₂₄alkyl, interrupted by one or more Z₃; C₂-C₂₄alkenyl; C₂- C₂₄alkenyl interrupted by one or more Z₃; C₃-C₂₅cycloalkyl; and C₃-C₂₅cycloalkyl interrupted by one or more Z₃ optionally are substituted by one or more OH or halogen; Z₃ is O, S Or NR₅₄; and R6₄, Res and Rββ independently of one another are hydrogen, Ci-C₂₄alkyl, CH₂-COOH,

COOH, or phenyl, with the proviso that at least one unsaturated group — Z₁-C=C-R₆₆ o R₆₄ R₆₅ and/or — Z₁-C-C — C— R ^{1 x} ₁₆₆ is present.

Another class of activatable compounds are alkoxyamine initiators useful for the preparation of complex polymeric architectures starting from a wide range of monomers, such as for example styrenic, acrylic, methacrylic and diene-type monomers.

Alkoxyamine initiators, from which the activatable group can be derived are compounds of formula (Xl), (XII) and (XIII):

(XIII), wherein Q is

wherein R₂oo is independently H or d-C₄alkyl;

D is O or NR₂₀₃; in formula (I) m and n independently are a number 0 or 1 wherein at least one of both is 1 ; if in formula (I) m = 0 and n = 1

wherein

^* denotes where the group is attached to the oxygen atom;

A is O Or NR₂₀₃;

B₁ is C-ι-C₂₅alkylene, which may be interrupted by O or NR₂₀₃ groups, C₅-C₇cycloalkylene which can contain O and or NR₂₀₃ groups in the ring, which both are unsubstituted or substituted by C-i-Cβalkoxy, halogen or a group -COO(CrC-i8alkyl) or phenylene; additionally -A-B₁- can be a direct bond; or if A is -O- and D is NR₂₀₃, B₁ can be a direct bond; or if A is NR₂₀₃ and D is O or NR₂₀₃, B₁ can be a direct bond;

E is a direct bond or a -C(O)- group;

R₂₀₁₁ R₂₀₂ and R₂₀₃ are independently H, C-ι-C₁₈alkyl, which is unsubstituted or substituted by

CrC₈alkoxy, halogen or a group -COO(CrC₁₈alkyl), C₅-C₇cycloalkyl, which is unsubstituted or substituted by C-ι-C₈alkoxy, halogen or a group -COO(CrC-i₈alkyl), phenyl, which is unsubstituted or substituted by CrC₈alkoxy, CrC₈alkyl, halogen or a group -COO(C₁-

Ciβalkyl);

the group :N — is

wherein

A is as defined above; and if A is O, E₁ is -CH₂- if A is NR₂₀₃, E₁ is -C(O)-, -CH₂- or a direct bond;

R₂₀₄, R₂₀₅, R₂₀₆ are independently CrC₁₈alkyl, C₅-C₇cycloalkyl, C₇-C₉phenylalkyl or phenyl;

R₇, R₈ are independently H, CrC₁₈alkyl, C₅-C₇cycloalkyl, C₇-C₉phenylalkyl or CrC₁₈acyl;

L is a direct bond, O or NR₂₀₇;

R209, R2K) are independently H or CrC₁₈alkoxy, if R₂₀₉ is H, R₂₁₀ is additionally OH, -O-(C_rC₁₈)acyl, -NR₂₀₃-(C₁-C₁₈)BCyI or N(R₂₀₃)₂; or

R₂₀₉ and R₂₁₀ together with the C-atom to which they are bonded form a cyclic ketale group

wherein k is 0, 1 or 2 and R₁₅ is C_rC₁₈alkyl, -CH₂-OH or

CH₂-O-(C_rC₁₈)acyl; or

R₂₀₉ and R₂₁₀ together form the group =0, or =N-A-R₂₀₇; R₂₁₁, R₂₁₂, R₂₁₃ and R₂₁₄ are independently of each other CrC₄alkyl; if in formula (I) m = 1 and n = 1 X is as defined above;

the group is

wherein A and B₁ are as defined above; if in formula (I) m = 1 and n = 0

wherein A is O, NR₂03 or a direct bond and E, R₂oi and R₂0₂ are as defined above; B₃ is H, CrC₂5alkyl, which may be interrupted by O or NR₂03 groups, C₅-C₇cycloalkyl, which can contain O and or NR₂03 groups in the ring, which both are unsubstituted or substituted by CrC₈alkoxy, halogen or a group -COO(CrCi₈alkyl) or d-Ci₈alkoxy or phenyl;

the group is

wherein A and B₁ are as defined above; in formula (II)

^* denotes where X is attached to the oxygen atom and A, B₁, E, R₂oi and R₂0₂ are as defined above;

the group is

wherein A is as defined above;

L₁ is a divalent group derived from an aliphatic dicarboxylic acid having 2 to 18 carbon atoms from an aromatic dicarboxylic acid or from an aliphatic-aromatic dicarboxylic acid; in formula (III)

X₁ is a group

wherein B₂ is a direct bond, C-ι-C₂5alkylene, which may be interrupted by O or NR₂03 groups, C₅-C₇cycloalkylene which can contain O and or NR₂03 groups in the ring, which both are unsubstituted or substituted by C-i-Cβalkoxy, halogen or a group -COO(CrC-i8alkyl) or phenylene, wherein when B₂ is a direct bond one A is O and the other is NR₂03; A, B₁, R₂O₁ and R202 are as defined above and

the group is

wherein B₁ and A are as defined above.

Q is preferably , wherein R₂₂0 is independently H or CrC₄alkyl; and D is O or

NR₂₀₃.

In a further embodiment the present invention relates to polymerizable compositions comprising a) at least one ethylenically unsaturated monomer; b) a radical polymerization initiator; and c) silicon oxide flakes having bonded thereto a compound of formula (Xl), (XII) or (XIII).

The ethylenically unsaturated monomer is preferably selected from the group consisting of ethylene, propylene, n-butylene, i-butylene, styrene, substituted styrene, conjugated dienes, acrolein, vinyl acetate, vinylpyrrolidone, vinylimidazole, maleic anhydride, (alkyl)acrylic acidanhydrides, (alkyl)acrylic acid salts, (alkyl)acrylic esters, (alkyl)acrylonitriles, (alkyl)acrylamides, vinyl halides or vinylidene halides. In an especially preferred embodiment the ethylenically unsaturated monomer is a compound of formula CH₂=C(Ra)-(C=Z₄)-R_b, wherein Z₄ is O or S; R₃ is hydrogen or Ci-C₄alkyl; R_b is NH₂, 0^"(Me⁺), glycidyl, unsubstituted CrCi₈alkoxy, C₂-Ci₀₀alkoxy interrupted by at least one N and/or O atom, or hydroxy-substituted C-i-C-iβalkoxy, unsubstituted Ci-C-iβalkylamino, di(Ci-Ci₈alkyl)amino, hydroxy-substituted Ci-Ci₈alkylamino or hydroxy-substituted di(C_r Ci₈alkyl)amino, -O-CH₂-CH₂-N(CH₃)₂ or -O-CH₂-CH₂-N⁺H(CH₃)₂ An^"; An^" is a anion of a monovalent organic or inorganic acid; Me is a monovalent metal atom or the ammonium ion. Examples of the radical polymerization initiator are azo compounds, peroxides, peresters and hydroperoxides.

In addition, the present invention relates to a process for preparing an oligomer, a cooligomer, a polymer or a copolymer (block, random or graft) by free radical polymerization of at least one ethylenically unsaturated monomer or oligomer, which comprises (co)polymerizing the monomer or monomers/oligomers in the presence of a) a free radical initiator; and b) silicon oxide flakes having bonded thereto a compound of formula (Xl), (XII) or (XIII), a polymeric or oligomeric macroinitiator obtainable by the process and the use of the polymeric macroinitiator obtainable in the process as radical initiator for the polymerization of ethylenically unsaturated monomers.

In the process for preparing an oligomer, a cooligomer, a polymer or a copolymer the polymerization is carried out by applying heat or electromagnetic radiation from microwaves to γ-radiation, especially by heating and takes place at a temperature between 0°C and 160°C.

The polymeric macroinitiator can be used in a process for preparing a comb, star, tapered or branched polymer or copolymer by controlled free radical polymerization (CFRP). The process comprises polymerizing at least one ethylenically unsaturated monomer in the presence of the polymeric macroinitiator.

Examples of preferred alkoxyamine initiators are shown below:

The compounds are bonded to the silicon oxide flakes by a hydrosilylation reaction, wherein, for example, the following product is obtained:

In principle, any compound having a reactive double bond can be bonded to the reactive silicon oxide flakes by a hydrosilylation reaction:

, wherein

R¹⁰⁰, R¹⁰¹, R¹⁰² and R¹⁰³ are independently of each other hydrogen, or an organic group. The hydrosilylation can be initiated by UV radiation and can be catalysed by radical formers, transition metal complexes, or Lewis bases.

Examples of hydrosilylation catalysts are metallic and finely divided platinum which may be disposed on supports such as silica, alumina or activated carbon, compounds or complexes of platinum such as platinum halides, for example H₂PtCIe 6H₂O, PtCI₄, Na₂PtCI₄ 4H₂O, platinum-olefin complexes, platinum-alcohol complexes, platinum-alkoxide complexes, platinum-ether complexes, platinum-aldehyde complexes, platinum-ketone complexes, including reaction products of H₂PtCI₆ 6H₂O and cyclohexanone, platinum-vinylsiloxane complexes such as platinum-1 ,3-divinyl-1 ,1 ,3,3-tetramethyldisiloxane complexes with or without content of detectable inorganically bonded halogen, bis(γ-picoline)platinum dichloride, trimethylenedipyridineplatinum dichloride, dicyclopentadieneplatinum dichloride, dimethylsulfoxyethyleneplatinum(ll) dichloride, and reaction products of platinum tetrachloride with olefins and primary amine or secondary amine or primary and secondary amine, such as the reaction product of platinum tetrachloride dissolved in 1-octene with sec-butylamine, and ammonium-platinum complexes.

The hydrosilylation catalyst is preferably a transition metal from group (VIII) of the Periodic Table or a compound or a complex of these transition metals, particularly preferred transition metals being from the group of the palladium or platinum metals. Especially preferred among these are platinum, palladium, rhodium and iridium, and the compounds and complexes thereof, such as H₂PtCI₆, RhCI(PPh₃)₃ or trans-lrCI(CO)(PPh₃)₂ as with R¹R²C=CR³R⁴. The hydrosilylation process may be carried out with or without solvent as a 1 -phase or 2- phase reaction, or in dispersion, for example as micro- or macroemulsions. Examples of suitable solvents which can be used in the process are pentane, petroleum ether, n-hexane, hexane isomer mixtures, cyclohexane, heptane, octane, petroleum benzine, decalin, benzene, toluene, xylene, isopropanol, butanol and isomers thereof, diethyl ether, di-n-propyl ether, diisopropyl ether, di-n-butyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, methyl acetate, ethyl acetate, n-, sec- and tert-butyl acetate, dichloromethane, trichloromethane, tetrachloromethane, 1 ,2-dichloroethane, trichloroethylene, tetrachloroethylene, chlorobenzene, linear and cyclic siloxanes and mixtures of the solvents mentioned.

The process according to the invention is preferably carried out at a pressure of the surrounding atmosphere, i.e. from about 900 to 1 100 hPa, but it can also be carried out at higher and lower pressures, and is preferably carried out at a temperature of from 20 to 200 °C, more preferably from 50 to 180°C and most preferably from 60 to 130°C.

On completion of the reaction, the reaction products obtained may be isolated by any suitable process steps, these being well known to the skilled artisan. If desired, volatile components and any solvent used may be removed by distillation after the reaction.

There are various possibilities to modify silicon oxide flakes by that way. Some examples are given below, but the invention is not limited thereto, a) poly(n-butyl acrylate) modified silicon oxide flakes:

The poly(n-butyl acrylate) macromonomer with acrylate endgroup is synthesized with ATRP technology according to A. Mϋhlebach, F. Rime J. Polym. Sci., Polym. Chem. Ed., 2003, 41 ,

3425. b) UV-absorber modified silicon oxide particles:

^* antioxidant modified silicon oxide particles:

ιi > polyethyleneglycol modified silicon oxide particles: reactive ,0- o- silicon oxide flake

Jn silicon oxide flake O

O o-

O e) caprolactone modified silicon oxide particles:

In addition, the reactive silicon oxide flakes can be reacted with organic groups, which comprise polymerizable groups. Such products can be represented by the following formula

(Z₄)_d-C(R⁴¹ )_e-R⁴²-(Y)_f-|sϊϊicon oxide flake d is an integer of 1 to 3, e is 0, 1 or 2, wherein the sum of a and b is 3, f is O, or 1 , Z₄ is a polymerizable group,

R⁴¹ is hydrogen, or a substituent,

R⁴² is a linkage or spacer group,

Y is -O-, -S-, -R⁴³N-, or -C(=O)O-, wherein R⁴³ is hydrogen, or an organic group, and silicon oxide flake is a silicon oxide flake derived from the reactive silicon oxide flake.

Examples of R⁴³ are hydrogen, d-Cβalkyl, and C₆-Ci₂aryl, which can be substituted.

Examples of Z are -OH, -NH₂, -C(R⁴⁴)=CH₂, -OC(O)-C(R⁴⁵)=CH₂, -C(O)-C(R⁴⁶)=CH₂, C₅-

H₂ -C C -C = CH

/I \λ I l I l C/cycloalkenyl, -CO — (^X V c = C - R⁴⁶ , °_{χ /}° ■ or O O . wherein ^{v co} co

R⁴⁴ is hydrogen, or Ci-C₄alkyl, or halogen, R⁴⁵ is hydrogen, Ci-C₄alkyl, or halogen, and R⁴⁶ is hydrogen, CrC₄alkyl, or C₆-Ci₂aryl.

Examples of R⁴² are substituted and unsubstituted alkylene groups, arylene groups, cycloalkylene, arylenealkylene groups and alkylenearylene groups each having 1 to 10 ccaarrbboonn aattoommss,, wwhhiicchh ccaarn be interrupted by an oxygen atom, a sulfur atom, or an NR⁴³ group, especially an NH group.

The term "alkylene (spacer)" is typically CrC3oalkylene, preferably C-i-C-iβalkylene, and embraces the linear as well as the branched representatives and can be, for example, -CH₂- and C₂-C₃₀alkylene, such as -(CHz)₂-, -CH(Me)-, -(CHz)₃-, -CH₂-CH(Me)-, -C(Me)₂-, -(CHz)₄-, -(CH₂)S-, -(CHz)₆-, -(CH₂)7-,-(CHz)β-, -(CHz)₉-, -(CH₂)₁₀-, -(CH₂)n-, -(CH₂)iz-, -(CH₂)₁₃-, -(CH₂)i₄-, -(CH₂)i₅-, -(CH₂)i₆-, -(CH₂)i₇-, -(CH₂)iβ-, -(CH₂)ig-, -(CH₂)₂o , -(CH₂)₂₁-, -(CH₂)₂₂-, -(CHz)₂₃-, -(CHz)₂₄-, -(CH₂)₂₅-,-(CH₂)₂₆-, -(CHz)₂₇-, -(CH₂)₂₈-, -(CHz)₂₉-, -(CH₂J₃₀-, preferably -CH₂-, -(CHz)₂-, -(CH₂)S-, -(CHz)₄-, -(CHz)₅-, -(CHz)₆-, -(CHz)₇-, -(CHz)₈-, -(CHz)₉-, -(CH₂)₁₀-, -(CH₂)H-, -(CHz)iz-, -(CH₂J₁₃-, -(CH₂)I₄-, -(CH₂J₁₅-, -(CH₂J₁₆-, -(CH₂J₁₇-, -(CH₂J₁₈-, and also -CH(C₂-C3oalkylene)-. The "alkylene spacer" can optionally comprise one or more, in particular one or two groups selected from -O-, -S-, -NR⁴³-, -CO-, -CONH-, -CON⁴³-, or - COO- as linking group. CrC₃₀alkylene can, for example, be interrupted several times by -O-, -S-, -NH- Or -C(O)NH-, such as -(CH₂)₂-O-(CH₂)-, -(CH₂)₂-O-(CH₂)₂-, -(CH₂)₂-S-(CH₂)₂-, - CH₂-CH-CH₂-O-(CH₂)p-CH₃, wherein p is an integer from 1 to 10; or -CHX₁₃CH₂-(X₁₄)_n3-OH, wherein X₁₃ is C-i-Cβalkyl, X₁₄ is an alkylene oxide monomer, preferably ethylene oxide or propylene oxide, or alkylene amino monomer, preferably amino ethylene or amino propylene, and n3 is an integer from 1 to 10, preferably 1 to 5; or -(CH₂)₂-NH-(CH₂)₂- or -(CHz)₂-C(O)N H-(CHz)₂-.

"Arylene (spacer)" is an unsubstituted or substituted carbocylic or heterocyclic arylene group, preferably containing 6 to 14 carbon atoms, typically phenylene, naphthylene, anthracenylene, anthraquinonylene, pyridinylene, quinolinylene, preferably a group

wherein X₁₁ is a single bond in ortho-, meta- or para-position, or -O-, -S-, -NR⁴³-, -CO-, - CONH-, -CONR⁴³-, or -COO- in ortho-, meta- or para-position; para-phenylene and para- phenylenoxy are preferred.

"Aralkylene (spacer)" is an unsubstituted or substituted carbocylic or heterocyclic aralkylene

group, preferably containing 6 to 14 carbon atoms, preferably a group

wherein X₁₁ is a single bond in ortho-, meta- or para-position, or -O-, -S-, -NR⁴³-, -CO-, -CONH-, -CONR⁴³-, or -COO- in ortho-, meta- or para-position, and X₁₂ is alkylene, or a

group , wherein X₁₂ is alkylene in ortho-, meta- or para-position and

X₁₁ is a single bond, -0-, -S-, -NR⁴³-, -CO-, -CONH-, -CONR⁴³-, or -COO-.

"Cycloalkylene (spacer)" is an unsubstituted or substituted carbocylic or heterocyclic cycloalkylene group, preferably containing 6 to 14 carbon atoms, typically cyclohexylene,

preferably a group

wherein X₁₁ is a single bond in 2-, 3- or 4-position, or -0-, -S-, -NR⁴³-, -CO-, -CONH-, -CONR⁴³-, or -COO- in 2-, 3- or 4-position; 4-cyclohexylene and 4-cyclohexylenoxy are preferred. Examples of particularly suitable compounds, from which the polymerizable group can be derived are listed below:

The silicon oxides having polymerizable groups according to the invention, together with other copolymerizable components as needed, are polymerized to form an organic network. The polymerization can occur, e.g. thermally, in a redox induced manner, covalent- nucleophilically and/or photochemically using methods described, e.g. DE-A-3143820, 3826715 and 3835968.

A preferred embodiment of the present invention is the use of the silicon oxides having polymerizable groups as reinforcer of coatings and improver of scratch resistance in coating compositions for surfaces.

The present invention also relates to a process for protecting a substrate, which comprises applying thereto a coating composition comprising silicon oxides having polymerizable groups and then drying and/or curing it.

The present invention likewise relates to a process for preparing a reinforced coating with improved scratch resistance on a surface, which comprises treating this surface with a coating composition comprising silicon oxides having polymerizable groups, and then drying and/or curing it.

In addition, the product obtainable by reacting a SiO_y flake, or a material comprising a SiO_y layer with 0.70 < y < 1.95, especially 0.70 < y < 1.80, very especially 1.0 < y < 1.8 with a protic substance, such as water, or a protic organic solvent to generate Si-H, Si-H₂ and/or a-Si:H groups can be used as reductive agent, such as, for example, the hydrogenation of organic compounds. The present invention is illustrated in more detail on the basis of the porous silicon oxide flakes having Si-H, Si-H₂ and/or a-Si:H groups on their surface and in their pores, but not limited thereto. Non-porous silicon oxide flakes having Si-H, Si-H₂ and/or a-Si:H groups on their surface, which can, in principal, be prepared in analogy to the process described below, are also suitable.

The porous silicon oxide flakes are, in principal, obtainable by a process described in WO04/065295. Said process comprises the steps of: a) vapor-deposition of a separating agent I onto a carrier to produce a separating agent layer, b) the simultaneous vapor-deposition of SiO_y and the separating agent I onto the separating agent layer (a), c) the separation of SiO_y from the separating agent I, wherein 0.70 < y < 1.95, by dissolution in water, or a protic organic solvent.

The platelike porous material can be produced in a variety of distinctable and reproducible variants by changing only two process parameters: the thickness of the mixed layer of SiO_y and the separating agent and the amount of the SiO_y contained in the mixed layer.

The separating agent vapor-deposited onto the carrier in step a) may be an organic substance soluble in protic organic solvents, or water and vaporisable in vacuo, such as anthracene, anthraquinone, acetamidophenol, acetylsalicylic acid, camphoric anhydride, benzimidazole, benzene-1 ,2,4-tricarboxylic acid, biphenyl-2,2-dicarboxylic acid, bis(4- hydroxyphenyl)sulfone, dihydroxyanthraquinone, hydantoin, 3-hydroxybenzoic acid, 8- hydroxyquinoline-5-sulfonic acid monohydrate, 4-hydroxycoumarin, 7-hydroxycoumarin, 3- hydroxynaphthalene-2-carboxylic acid, isophthalic acid, 4,4-methylene-bis-3-hydroxy- naphthalene-2-carboxylic acid, naphthalene-1 ,8-dicarboxylic anhydride, phthalimide and its potassium salt, phenolphthalein, phenothiazine, saccharin and its salts, tetraphenylmethane, triphenylene, triphenylmethanol or a mixture of at least two of those substances. The separating agent is preferably an inorganic salt soluble in water and vaporisable in vacuo (see, for example, DE 198 44 357), such as sodium chloride, potassium chloride, lithium chloride, sodium fluoride, potassium fluoride, lithium fluoride, calcium fluoride, sodium aluminium fluoride and disodium tetraborate, or a mixture of at least two of those substances. Examples of protic substances are water, alcohols and phenols. Preferred protic organic solvents are CrC₈alcohols, such as methanol, ethanol, propanol, isopropanol, butanol, tert- butanol, pentanol, tert-amyl alcohol or hexanol and also mixtures of these with water. Suitable protic organic solvents are also mixtures of ethers or glycol ethers, such as, for example, diethyl ether, dibutyl ether, ethyl methyl ether, diisopropyl ether, tert-butyl methyl ether, anisole, dioxane, tetrahydrofuran, monoglyme, diglyme and formaldehyde dimethylacetal, with water or with one of said alcohols, such as a mixture of a C-i-Cβalcohol with an ether or glycol ether, in particular a mixture of methanol, ethanol or water with diethyl ether, tetrahydrofuran, dioxane, glyme or diglyme. The C-i-Cβalcohol can also be a polyvalent d- C₈alcohol, which can be chosen from diols such as butanediol, and triols such as glycerol.

In detail, an organic separating agent, for example pentaerythritol (C(CH₂OH)₄), followed successively by a layer of silicon suboxide (SiO_y) and an organic separating agent, pentaerythritol, is vapor-deposited onto a carrier, which may be a continuous metal belt, passing by way of the vaporisers under a vacuum of < 0.5 Pa.

The mixed layer of silicon suboxide (SiO_y) and separating agent is vapor-deposited by two distinct vaporizers, which are each charged with one of the two materials and whose vapor beams overlap, wherein the separating agent is contained in the mixed layer in an amount of 1 to 60 % by weight based on the total weight of the mixed layer.

The thicknesses of organic separating agent vapor-deposited are about 20 nm to 100 nm, especially 30 to 60 nm, those of the mixed layer from 20 to 2000 nm, especially 50 to 500 nm depending upon the intended characteristics of the product.

The carrier is immersed in a dissolution bath, i.e. water. With mechanical assistance, the separating agent layer rapidly dissolves and the product layer breaks up into flakes, which are then present in water in the form of a suspension. The porous silicon oxide flakes can advantageously be produced using an apparatus described in US-B-6,270,840.

The suspension then present in both cases, comprising product structures and solvent (water), and the separating agent dissolved therein, is then separated in a further operation in accordance with a known technique. For that purpose, the product structures are first concentrated in the liquid and rinsed several times with fresh solvent in order to wash out the dissolved separating agent. The product, in the form of a solid that is still wet, is then separated off by filtration, sedimentation, centrifugation, decanting or evaporation. A SiOi oo-₁ 8 layer is formed preferably from silicon monoxide vapour produced in the vaporiser by reaction of a mixture of Si and Siθ₂ at temperatures of more than 1300°C.

A SiOo 7o-o 99 layer is formed preferably by evaporating silicon monoxide containing silicon in an amount up to 20 % by weight at temperatures of more than 1300°C.

The production of porous SiO_y flakes with y > 1 can be achieved by providing additional oxygen during the evaporation. For this purpose the vacuum chamber can be provided with a gas inlet, by which the oxygen partial pressure in the vacuum chamber can be controlled to a constant value.

Claims

1. A product obtainable by reacting a SiO_y flake, or a material comprising a SiO_y layer with 0.70 < y < 1.95, especially 0.70 < y < 1.80, very especially 1.0 < y < 1.8 with a protic substance, such as water, or a protic organic solvent to generate Si-H, Si-H₂ and/or a-

Si:H groups and reacting the obtained intermediate with a compound having functional groups that can react with Si-H, Si-H₂ and/or a-Si:H groups.

2. The product according to claim 1 , wherein the product is a silicon oxide flake which has a length of from 1 μm to 5 mm, a width of from 1 μm to 2 mm, and a thickness of from

20 nm to 1.5 μm, and a ratio of length to thickness of at least 2 : 1 , the flake having two substantially parallel faces, the distance between which is the shortest axis of the particles.

3. The product according to claim 2, wherein the silicon oxide flake (intermediate) is non- porous and has Si-H, Si-H₂ and/or a-Si:H groups on its surface.

4. The product according to claim 2, wherein the silicon oxide flake (intermediate) is porous and has Si-H, Si-H₂ and/or a-Si:H groups on its surface and in its pores, or only in its pores.

5. A process for preparing the silicon oxide flakes according to claim 3, comprising the steps of: a) vapor-deposition of a separating agent onto a carrier to produce a separating agent layer, b) the vapor-deposition of SiO_y onto the separating agent layer (a), c) the separation of SiO_y from the separating agent, wherein 0.70 < y < 1.80, by dissolution in water, or a protic organic solvent,

(d) reacting the silicon oxide flakes obtained in step c) and having Si-H, Si-H₂ and/or a- Si:H groups on their surface with a compound having functional groups that can react with the Si-H, Si-H₂ and/or a-Si:H groups, on their surface.

6. A process for preparing the silicon oxide flakes according to claim 4, comprising the steps of: a) vapor-deposition of a separating agent onto a carrier to produce a separating agent layer, b) the simultaneous vapor-deposition of SiO_y and the separating agent onto the separating agent layer (a), c) the separation of SiO_y from the separating agent, wherein 0.70 < y < 1.80, by dissolution in water, or a protic organic solvent, (d) reacting the silicon oxide flakes obtained in step c) and having Si-H, Si-H₂ and/or a-

Si:H groups with a compound having functional groups that can react with the Si-H, Si- H₂ and/or a-Si:H groups; or

a) vapor-deposition of a separating agent I onto a carrier to produce a separating agent layer, b) the simultaneous vapor-deposition of SiO_y and a separating agent II, which is dissolvable in an inert organic solvent, but not in water, or the protic organic solvent, onto the separating agent layer (a), c) the separation of SiO_y from the separating agent I, wherein 0.70 < y < 1.95, by dissolution in water, or the protic organic solvent, and d) reacting the silicon oxide flakes obtained in step c) and having Si-H, Si-H₂ and/or a- Si:H groups on their surface with a compound having functional groups that can react with the Si-H, Si-H₂ and/or a-Si:H groups, and

(e) the dissolution of the separating agent Il in the inert solvent; or

a) vapor-deposition of a separating agent Il onto a carrier to produce a separating agent layer, b) the simultaneous vapor-deposition of SiO_y and a separating agent I onto the separating agent layer (a), b') the separation of SiO_y from the separating agent II, wherein 0.70 < y < 1.95, by dissolution in the inert solvent, b") the removal of the reactive centres obtained in step b'), c) the dissolution of the separating agent I in water, or a protic organic solvent, and d) reacting the silicon oxide flakes obtained in step c) and having Si-H, Si-H₂ and/or a- Si:H groups with a compound having functional groups that can react with the Si-H, Si-

H₂ and/or a-Si:H groups.

7. A product, obtainable by the process according to claim 5, or 6.

8. Use of a product obtainable by reacting a SiO_y flake, or a material comprising a SiO_y layer with 0.70 < y < 1.95, especially 0.70 < y < 1.80, very especially 1.0 < y < 1.8 with a protic substance, such as water, or a protic organic solvent to generate Si-H, Si-H₂ and/or a-Si:H groups for providing chemically modified SiO_y flakes, or chemically modified SiO_y layers.

9. Use of a product obtainable by reacting a SiO_y flake, or a material comprising a SiO_y layer with 0.70 < y < 1.95, especially 0.70 < y < 1.80, very especially 1.0 < y < 1.8 with a protic substance, such as water, or a protic organic solvent to generate Si-H, Si-H₂ and/or a-Si:H groups as reductive agent.