FR2606022A1 - SINGLE-COMPONENT LIQUID ADHESIVE COMPOSITION BASED ON A PHOSPHATE AND AN ETHYLENICALLY UNSATURATED MONOMER AND ITS USE IN DENTAL ART - Google Patents

Abstract

THE INVENTION RELATES TO A SINGLE-COMPONENT LIQUID ADHESIVE COMPOSITION, CURABLE BY VISIBLE LIGHT, HAVING A VISCOSITY AT 25C OF LESS THAN 25 MPA.S. THE COMPOSITION INCLUDES: A. 2 TO 20 PARTS BY WEIGHT OF AT LEAST ONE PRACTICALLY PURE PHOSPHORIC ESTER OF FORMULACH C (R) .CO.OROP (O) (OH) IN WHICH R IS A HYDROGEN ATOM OR A GROUP METHYL ET R REPRESENTS: -CH-CH-, -CHCH (CH) -OR-CH (CH) -CH- B. 98 TO 80 PARTS BY WEIGHT OF AT LEAST ONE ETHYLENIC NON-SATURATION MONOMER COPOLYMERISABLE WITH ESTER PHOSPHORIC, AND AN EFFECTIVE QUANTITY OF A CATALYST ACTIVE BY VISIBLE LIGHT. THE COMPOSITION OF THE INVENTION CAN BE USED AS A TRIM IN DENTAL RESTORATION WORKS AND AS A PRIMER FOR ADHESIVES USED FOR ORTHODONTIC HOOKS AND CROWNS.

Description

The present invention relates to compositions

  adhesives and, in particular, polymeric compositions

  sand capable of strongly adhering to hard and rigid body tissue, such as teeth and bones. The compositions of the invention can be used as

  fittings with resilient dental compositions

  filling by filling can be applied, and as primers to which dental adhesives can be applied with a view to placing, for example, orthodontic hooks or crowns. The present invention therefore relates to the use of new compositions as priming compositions in a process aimed at restoring teeth, adhering to

  teeth or changing the position of teeth.

  Amalgam and filling compositions for dental restoration do not adhere well to the surface of the teeth. When filling a dental cavity, the problem of poor adhesion can be compensated for by the preparation of recalibrated cavities in order to improve the mechanical retention of the filling product. In the case of enamel surfaces, the mechanical calaae can be improved on a smaller scale

  by stripping the surface with phosphoric acid.

  However, a truly adhesive system would allow

  the dentist to improve the operating procedures.

  The use of phosphoric acid could be greatly reduced or even eliminated in some cases; restorative procedures involving dentine removal could be performed with a very reduced level of vital tissue removal; a marginal defect

  seal could be reduced.

  It should be considered that an adhesive system in association with bone and teeth constitutes

  a real material, that is to say that this system is in combination

  ciation with living dynamic tissue, and as such, any adhesive is likely to be the result of a compromise between competing influences. For example, adhesion to the surface of a tooth requires the presence of hydrophilic groups, but their presence increases the likelihood that the adhesive will be unstable upon hydrolysis. Nevertheless, the practitioner has a certain number of adhesives and almost all of them are based on esters.

  organic phosphoric acid. It is therefore very desirable-

  ble that the active adhesive component has a low concentration

  in the adhesive composition and, therefore, this compound

  health requires very good adhesive properties.

  The composition must have a low viscosity so

  that it flows easily over the surface to be bonded.

  The specification of European Patent No. 074 708 discusses a considerable number of patents in which various phosphorous esters containing ethylenic nonsaturation are described as adhesives. In this specification, specific phosphoric esters based on a long chain alkyl ester of acrylic and methacrylic acids are claimed and are considered to be

  with very good adhesive properties in applications

  dental cations. This specification states that 2-methacryloyloxyethyl dihydrogen phosphate is a relatively poor adhesive component and produces blistering in a paint film. The patent application

  European No. 115 948 describes the use of organic esters

  pyrophosphoric nics as polymerizable adhesive components. European patent applications N 058 483 and O 132 318 describe the use of esters of halophosphorous acids as polymerizable monomers in a dental adhesive; these esters contain at least one ethylenically unsaturated functional group and a chlorine or bromine atom attached directly to the atom

phosphorus.

  The specification of the U.S. patent

  No. 4,044,044 describes the use of phosphoric esters of hydroxyacrylates as components in anaerobic adhesive compositions. These compositions are considered to remain in the liquid state as long as they remain in contact with air, while it is claimed that they harden quickly by polymerization away from air. These adhesive compositions are useful as materials preventing disintegration, in particular under

high pressure.

  The Applicant has just found that the adhesive properties linked to polymerizable esters of phosphoric acid depended on the degree of impurity of the particular ester. Therefore, if a dihydrogen phosphoric ester is substantially free of phosphoric acid, the monohydrogen ester and the fully esterified form, the resulting adhesive composition

  is surprisingly effective as an adhesive in a

  quite watery. The present invention provides storage stable adhesive compositions which are

  capable of hardening quickly in the presence of air.

  In accordance with the present invention there is provided a one-component liquid adhesive composition, curing in visible light, having a viscosity at 25 C of less than 25 mPa.s, which comprises

  (a) 2 to 20 parts by weight of at least one phospho- ester

1 2

  practically pure risk of formula CH2 = C (R) .CO.O.R.

2 1 2

  OP (O) (OH) in which R is a hydrogen atom or a

  methyl group and R is a group -CH2-CH2-, -CH2-CH (CH3) -

or -CH (CH3) -CH2- and

  (b) 98 to 80 parts by weight of at least one non-monomer

  ethylenic saturation copolymerizable with the phosphoric ester, and an effective amount of a catalyst activated by visible light. The phosphorus ester component of the compositions of the invention is preferably 2-methacryloyloxypropyl dihydrogen phosphate. The phosphoric esters used in the compositions of the present invention can be prepared for example by reaction of hydroxyalkyl acrylate (or methacrylate) with at least an equimolar amount of phosphorus oxychloride in the presence of a tertiary amine, followed by '' a hydrolysis of all

  remaining chlorine-phosphorus bonds. The dihydrogen ester

  phosphorus is then purified by a series of washing and extraction operations so that it is practically

  pure, i.e. free from other phos-

  phoric so that this impurity rate is less than 5%

  by weight and preferably less than 2% by weight.

  The adhesive compositions of this

  invention contain at least one unsaturated monomer

  ethylenic copolymerizable with the phosphoric acid ester. The viscosity characteristics of the composition, such as the viscosity itself and the flow and wetting properties, are widely determined by those of the monomer. A wide range of monomer (s) is suitable for the compositions of the invention, as long as the viscosity of the resulting composition is less than 25 mPa.s at 25 C. The monomers which are most frequently used include those of types (meth) acrylate, vinyl urethane and styrene and acetate

  vinyl. However, other mono-

  mothers such as (meth) acrylamides, vinyl ethers, fumarates, maleates, vinyl ketones,

  vinylnitriles, vinylpyridines and vinylnaphtha-

  lene, alone or in combination, as long as the parameter

  viscosity of the composition is satisfied. The concentration

  tion of the phosphoric ester in the adhesive composition is preferably equal to or greater than 5% by weight and does not

  preferably not more than 15% by weight.

  Vinyl esters which can be advantageously used in the process of the present invention include, for example, vinyl acetate and acrylic acid esters of the formula CH2 = CH-COOR, in which R is an alkyl, aryl group , alkaryl, aralkyl or cycloalkyl. For example, R can be an alkyl group

  having 1 to 20 and preferably 1 to 10 carbon atoms.

  Particular vinyl esters which may be mentioned include, for example, methyl acrylate,

  ethyl acrylate, n-propyl and iso- acrylate

  propyl and the n-butyl, isobutyl and

tertiary butyl.

  Other suitable vinyl esters include

  take, for example, esters of the formula

4 3

CH2 = C (R) COOR

  wherein R4 is a methyl group. In the formula ester

CH2 = C (R) COOR3

  R3 and R may be the same or different.

  Particular vinyl esters which may be mentioned include, for example, methyl methacrylate, ethyl methacrylate, n-propyl isopropyl methacrylate and n-butyl, isobutyl and tertiary butyl methacrylate, esters vinyl such as n-hexyl, cyciohexyl and tetrahydrofurfuryl acrylates and methacrylates. The monomers must have low toxicity. Suitable aromatic vinyl compounds of the styrene type include, for example, styrene and its derivatives, for example the α-alkyl derivative of styrene, such as α-methylstyrene and

vinyltoluene.

  Suitable vinyl nitriles include, for example, acrylonitrile and its derivatives, for example

methacrylonitrile.

  Other ethylenically unsaturated monomers which can be used include vinylpyrrolidone and hydroxyalkyl acrylates and methacrylates, for example.

  example hydroxyethyl acrylate, hvdroxy acrylate-

  propyl, hydroxystethyl methacrylate and methacryl-

  hydroxypropyl late. Polyfunctional monomers can also be used as the materials to be polymerized, i.e.

  monomers which contain two or more vinyl groups.

  Suitable monomers include, for example, glycol dimethacrylate, diallyl phthalate and

triallyl cyanurate.

  The ethylenically unsaturated material may contain at least one ethylenically unsaturated polymer, advantageously in combination with at least one monomer.

ethylenically unsaturated.

  The composition of the invention is advantageous-

  free of volatile solvents. However, if a solvent is included, the following polymerizable materials may also be present, as long as the viscosity of the

  composition is less than 25 mPa.s at 25 C.

  Such polymerizable materials are

  preferably an ethylenically unsaturated liquid material

  such as vinyl urethane, for example, the materials described in British patent N 1 352 063, 1 465 097, 1 498 421 and in the patent application of the Federal Republic of Germany DE-OS N 2 419 887, or the reaction product of a diol such as glycol, but in particular a bisphenol, with an alycidyl alkacrylate of the type described for example in US Pat. Nos. 3,066,112 and 4,131 729 (the disclosures made in these factums are incorporated

here for information).

  A preferred product obtained by reaction of a glycidyl alkacrylate with a diol corresponds to the formula: CHj3 OH CH3 h2 = C-CO O-CH2-CH-CH2 CH3 Popular vinylurethanes described in British patents and in application DE- The above-mentioned OS are formed by the reaction product of a prepolymer

  urethane and an ester of acrylic or methacrylic acid

  than with a hydroxyalkanol of at least two carbon atoms

  bone, the urethane prepolymer being the reaction product

  tion of a diisocyanate of formula OCN-R5-NCO and of a diol of formula HO-R -OH, formulas in which R5 is a divalent hydrocarbyl group and R6 is the residue of a condensation product of an oxide d alkylene with an organic compound containing two phenolic or alcoholic groups. Other suitable vinyl urethanes include those obtained by reacting alkyl and aryl diisocyanates, preferably alkyl, with hydroxyalkyl acrylates and alkacrylates such as those described in British Patent Nos. 1,401,805 , i 428 672 and 1 430 303 (the disclosures made in these

  patents are incorporated here for documentary purposes).

  The dental compositions of the present invention are cured by irradiation with visible radiation, preferably those which have a wavelength.

  in the range of 400 to 500 mgm. So that the hard-

  Curing of the compositions can be carried out within this range, the compositions contain a catalyst which is activated by visible light. Such a catalyst advantageously contains at least one ketone chosen from the

  fluorenone and a diketone and at least one organic peroxide

fuck.

  Ketones which can be used in the composition of the present invention also exert a certain photosensitive catalytic action of themselves, without the presence of an organic peroxide. This activity of the ketone is favored by the addition of a reducing agent as described in the patent application of the Federal Republic of Germany DE- OS N 2 251 048. Consequently, the ketones of the invention are chosen between fluorone and a-diketones and their derivatives which, when mixed with a similar amount of an organic amine capable of reducing this ketone when the latter is in an excited state, but in the absence of organic peroxide, catalyze the maturation of an ethylenically unsaturated material. Signs of maturation can be conveniently detected by examining the

  variation in viscosity of a mixture of the material to be

  ethylenic saturation containing the ketone and the organic amine, each in a proportion of 1% by weight based on the ethylenically unsaturated material, using an oscillating rheometer, samples 2 mm thick, while the mixture is irradiated with light of a wavelength in the range of 400 to 500 mgm. Such an examination may be carried out using the method described in British Standard British Standard 5199, 1975, paragraph 6.4, provided that means are provided to allow visible light to be directed onto the mixture. The ketone

  preferably has a maturation time of less than 15 mi-

  nutes at an irradiation level of 1000 w / m2 as measured

  at 470 mgm with a bandwidth of - 8 mgm, in use

  for example, a Macam radiometer (Macam PhotometricsLtd.,

Edinburgh, Scotland).

  Diketones corresponding to the formula

A - C - C - A

  O O in which the groups A, which may be identical

  or different, are hydrocarbyl or hydrocarbon groups

  substituted byles which may further be linked together by a direct junction or by a hydrocarbyl or divalent substituted hydrocarbyl group, or in which the groups A may jointly form an aromatic ring

  condensed. Preferably, the groups A are identical.

  The groups A can be aliphatic or aromatic. Cycloaliphatic groups and aliphatic groups which carry aromatic substituents, i.e. aralkyl groups, fall within the scope of the definition of the term aliphatic. We also consider as falling within the framework of the definition of the expression aromatic group, groups which carry

  alkyl substituents, i.e. alkaryl groups.

  Heterocyclic groups are included as part of

  the definition of aromatic groups.

  The aromatic group can be an aromatic group.

  benzene material, for example the phenyl group, or it may be a non-benzene cyclic group known in the prior art for possessing the characteristics

of a benzene aromatic group.

  LesgroupesA, especially when they are flavored

  ticks, may bear substituent groups other than hydrocarbyl groups, for example a halogen or an alkoxy group. Substituents other than groups

  hydrocarbyl may cause inhibition of the polymer

  of ethylenically unsaturated material and if

  a-diketone contains such substituents, it is preferred

  rable that it is not present in the photopolymerizable composition at a concentration resulting in a significant inhibition of the polymerization of the material to be

  ethylenic unsaturation in the composition.

  The groups A can also be attached together by a direct bond or by a divalent group, for example a divalent hydrocarbyl group, that is to say that in addition to the bond by the group

-CC-

  o1 o 0 0 the groups A can also be attached so as to form a ring system of nuclei. For example, when the groups A are aromatic, the a-diketone can correspond to the formula (Y) m Ph - C - C - Ph Il Il 0 o in which Ph is a phenylene rump, Y is an aroupe> CH2, or it may be a corresponding derivative in which one or the other of the hvdroqene atoms or both are replaced by a hydrocarbyl group and the value 0, 1 or 2. Preferably, the qroupe Is attached to the aromatic groups in positions ortho to the group

- CC -

  0 0 Groups A can form jointly

  a system of condensed aromatic nuclei.

  In general, a-diketones are capable of being excited by radiation in the visible region of the spectrum, i.e. by light of length

  waves greater than 400 m.m, for example in the inter-

  wavelength valley from 400 to 500 mgm. For the present invention, the α-diketone must have low volatility so as to minimize the odor and the variation in concentration. Suitable a-diketones include benzile in which the two groups A are phenyl groups, a-diketones in which the groups A are both condensed aromatic groups, for example a-naphthile and B-naphthile, and a-diketones whose groups A are alkaryl groups, for example p-tolile. As an example of a suitable a-diketone in which the groups A are non-benzene aromatic groups, there may be mentioned a furile, for example 2,2'-furile. Adicetone derivatives in which groups A carry non-hydrocarbyl groups, for example

  example p, p'-dialkoxybenzile such as p, p'-dimethoxy-

  benzile or a p, p'-dihalobenzile such as p, p'-

  dichlorobenzile or p-nitrobenzile, can be incorporated

  porés. Groups A can be attached together by a single bond or by a divalent hydrocarbyl group to form a ring system of novals. By

  example, when groups A are aliphatic, the a-

  diketone can be camphoquinone.

  An example of a-diketone corresponding to formula I is phenanthraquinone in which the aromatic groups A are attached by a direct bond in ortho with respect to the group

-CC -

  O O Suitable derivatives include 2-bromo-, 2-nitro-,

  4-nitro-, 3-chloro-, 2,7-dinitro-, 1-methyl-7-isopropyl-

phenanthraquinones.

  The a-diketone can be acenaphthene-quinone in which the groups A jointly form a

  system of condensed aromatic nuclei.

  The ketone can also be fluorenone and its derivatives, for example derivatives of the lower alkyl type (C1 to C6), halo, nitro, carboxylic acid

  and esters, especially in positions 2 and 4.

  The ketone may, for example, be present in the composition at a concentration in the range of 0.01 to 2% by weight of the polymerizable material in the composition, although concentrations deviating from this range may be used if applicable. The ketone is advantageously present at a concentration of 0.1 to 1% and in particular 0.5 to 1% by weight of the ethylenically unsaturated material present in the composition. The ketone must be soluble in the polymerizable material and the above concentrations relate to

at concentrations in solution.

  The organic peroxides which can be advantageously used in the composition of the invention include those which correspond to the formula

R7 - O - 0 - R7

  wherein the R7 groups, which may be the same or different, represent hydrogen, alkyl, aryl or acyl groups, only one of the R groups can represent hydrogen. The term acyl denotes a group of formula

R8 - CO -

  wherein R8 is an alkyl, aryl, alkoxy or aryloxy group. The alkyl and aryl terms have the definitions given above for groups A and include

  substituted alkyl and aryl groups.

  Examples of organic peroxides which can be advantageously used in the composition of the present invention include diacetyl peroxide, dibenzoyl peroxide, ditertiobutyl peroxide, dilauroyl peroxide, tertiary butyl perbenzoate,

  di-tertiobutylcyclohexyl perdicarbonate.

  The organic peroxide may, for example, be present in the composition in the range of 0.1 to% by weight of the polymerizable material present in the composition, although it can be used if desired.

  a concentration outside this range.

  The reactivity of a peroxide is often expressed in terms of the half-life temperature after ten

  hours, that is to say that after ten hours at this temperature-

  ture, half of the oxygen has been made available.

  The peroxides in the compositions of the invention preferably have half-life temperatures after ten hours

  less than 150 C, especially less than 100 C.

  The speed at which the composition of the invention

  tion hardens under the influence of visible light can be accelerated by the incorporation into the composition of a reducing agent which is capable of reducing the ketone when the latter is in an excited state. Suitable reducing agents are described, for example, in the patent application of the Federal Republic of Germany DE-OS No. 2 251 048 mentioned above and include amines

  organic, phosphites, sulfinic acids.

  In general, preference is given to non-basic reducing agents because they are less prone to react with the phosphoric ester. Suitable non-basic reducing agents include aldehydes and organic tin compounds having the formula: (R9) n Sn (OR 10) m in which n and m are integers having the value 1, 2 or 3 and the sum n + m is 4, R9 is an alkyl or alkenyl group containing 1 to 18 atoms of

9 9

  carbon and R10 represents R9 or a group R9.CO-, or compounds of formula (/ R9 / Sn). The mixing of the components can be carried out by stirring together the polymerizable material and any filler. It may be useful to first dissolve the catalyst components in the polymerizable material; the polymerizable material can conveniently

  be diluted with a suitable diluent so as to improve

  improve the dissolution of the catalyst components, but this constitutes a less appreciated procedure. When the mixing has been carried out, the diluent can be removed, if necessary, for example by evaporation. The composition of the invention is preferably practically devoid of solvent, because the presence of a solvent can hinder adhesion and can cause problems.

of toxicity.

  Because the photosensitive catalyst makes the polymerizable material and the monomer sensitive to light in the visible range of 400 to 500 mgm, the portion

  of the preparation of the composition of this invention

  tion in which the photosensitive catalyst is added and subsequent handling, for example filling of containers, should be carried out mainly in the dark within this range. The preparation can be carried out more conveniently by using light outside this range, for example as it is emitted by electric discharge lamps in

sodium vapor.

  According to another aspect of the present invention, there is provided a maturation process which consists in irradiating the composition of the invention with visible light of wavelength in the range of 400 to 500 mgm. The process can be carried out at any suitable temperature, provided that the composition does not crystallize and does not fragment, in which case the temperature is too low, or does not volatilize

  undesirably, in which case the temperature is too high.

  The process is advantageously carried out at temperatures

  ambient tures, i.e. between 15 and 40 C.

  It is envisaged that the surface of a tooth is coated with the composition of the invention which hardens under the action of a visible light source, the composition being advantageously hardened using a source

bright portable.

  A dental composition according to the present invention is advantageously packaged in small single containers (for example with a capacity of g) so as to facilitate handling during the surgical intervention and to reduce the risk of inadvertent hardening. , for example by

diffused light.

  For cosmetic purposes, such a dental composition may have the appearance of a tinted, colored tooth.

  or natural and therefore the composition of the invention

  tion may contain small amounts of pigments, opalescent agents, etc. The composition may also contain small amounts of other materials such as antioxidants and stabilizers, as long as

  that they do not significantly affect the hardening.

  The invention is illustrated by the following examples:

Example 1

  (a) Preparation of a phosphoric acid ester Phosphorus oxychloride (127.9 g; 0.83 mole) was mixed with methylene chloride (600 cm3). The mixture was stirred and cooled to 0 C. A mixture of hydroxypropyl methacrylate (120 g; 0.83 mole),

  pyridine (65.8 g; 0.83 mole) and methyl chloride

  lene (400 cm ') was added dropwise to the mixture containing the phosphorus oxychloride over a period of minutes while maintaining the reaction temperature in the range of 0 to 3 C. The mixture was stirred

  for another 2 hours in this temperature range.

  The reaction mixture was then poured into 1 liter of cold water, and the chloromethyl phase was separated, washed twice with water. The chloromethylenic solution was then mixed with water and the methylene chloride was removed on a rotary evaporator, leaving an aqueous phase and some inorganic matter insoluble in water. The aqueous phase was washed twice with methylene chloride then carefully acidified (208 cm3 of hydrochloric acid) with stirring. The sentence

  The aqueous solution was then extracted with ethyl acetate (1 liter) and the aqueous phase obtained was discarded. The concen-

  Tration of the phosphoric ester was then estimated and analyzed by acid-base titration methods and found that the product contained as ester type impurity less than 2% by weight of 2-methacryloyloxypropyl dihydrogen phosphate. Another ethylenically unsaturated monomer (comonomer) was then added in

  desired proportion according to the relative concentrations

  tives must exist in the final composition. The ethyl acetate was then removed using an evaporator

  rotary at 65 C under a vacuum of 6.7 kPa.

  (b) The preparation of vinylurethane (VU) was carried out using the procedure described in Example 1

of European patent N 0 059 649.

  (c) Several formulations have been prepared having the concen-

  tration into comonomers and the composition indicated in Table 1. The catalyst components were added to the mixture of monomers as follows:% / Camphoquinone weight basis 0.73

Dimethylaminoethyl-

methacrylate (DMAEM) 0.49

tertiary perbenzoate

  butyl 0.98 "Topanol" O quantity adjusted to ppm relative to the final composition This addition and the subsequent operations relating to the composition were carried out in the light produced by electric discharge in sodium vapor. The evaluation of the adhesion strength on samples corresponding to the above formulations was carried out using the procedure described in the British Dental Journal of 1984, pages 93 to 95, except

  that the composite restorative material used combines

  The adhesive composition consisted of "Occlusin" (trademark of Imperial Chemical Industries PLC). The samples were hardened by irradiation using a halogen lamp with tungsten filaments comprising a tuned reflector and a filter

  dichrolque which eliminates ultraviolet rays; the inten-

  site was 1000 Wm-2 and the curing time was

30 seconds.

  "Topanol" is the trademark of a product from Imperial Chemical Industries PLC

  and "Topanol" O is 2,6-di-tert-butyl-4-methylphenol.

TABLE 1

  t 'tEster tE er Phosphoric ester phospho- Comonomer t T ric adhesion, (MPa) t 1 96% by weight 1 internal external t It ts tX I (pro (exterior 1 tI X | g smelter) superior) 0 x I RO - P - OH I 10 I (i) TEGDM 8, 0_3.6 1 18.1 ± 6.4 1 I 1 oxx l (ii) VU / TEGDM 6.0_3.8 1 14.24- + 6; 2 1 It OH (50) () t Proportion by weight t

80 7 1

O O O t

I I Il I 1 t t 1 1.

  I RO-PO-H + RO RRO-P-OR O-PR 35 I (iii) TEGDM 9.84-4.6 1 12.1 + 3.1 1 I [[t 50Xx (iv) VU / TEGDM 8 , 8 + 4.3 1 13.2 + 5.8 1 t OH OH OR I (50) (50) I Proportion by weight t

24 48 4 1

0 O 0

  RO-P-Cl + RO-P-OR + RO-P-OR I 20x (v) VU / TEGDM 3.4 + 1.5 1 8.1 + 2; 0 1 ctt (50) (50) t I Ci CJ OR t IIIO Scotchbond Up to (vi) bisGMA 3.9 + 2.0 1 10.2+ 14 1 It (<3M) 1 (in + ethanol) It II tt TEGDMi

CH3 0 CH3 CH3 O CH3

t tI t t t J

  Notes: R. CH2 = C- C- OCH2CH-, CH2 = C - C - -CHCH2-

  * In accordance with the present invention ** Adhesive applied in solution at 20% by weight in ethanol TEGDM - triethylene glycol dimethacrylate

EXAMPLE 2

  An adhesive formulation was prepared as

  described in Example 1, but of the following composition.

  Parts by weight Phosphoric ester (Example 1a) 9.78

TEGDM 90.22

  Camphoquinone 0.73 Dibutyltin dilaurate 0.49 Tertiary butyl perbenzoate 0.98 "Topanol" O at 200 ppm A sample of the above composition was ripened and this sample was evaluated

  as described in Example 1, which gave adhesion

  similar to that in Table 1 (i).

EXAMPLE 3

  A series of adhered compositions have been prepared

  sives as described in example 1 but using

  a whole range of tin compounds in place of DMAEM.

  Samples of the compositions were evaluated up to the time of maturation using the rheometer technique

* oscillating described above.

  Parts by weight Phosphoric ester (Example 1a) 15

TEGDM 85

  Camphoquinone 0.75 Tin compound 0.5 Tin compound Maturation time Tin compound (eods (seconds) None * 126 Dibutyltin diacetate 96 Dibutyltin dilaurate 90 Dioctyltin diacetate 75 Tributyltin acetate 30 Tributyltin methacrylate 43 Bis (tributyltin oxide) 30 Tributyltin methylate 24 * The same result is also obtained with 0.5% of DMAEM

Claims (10)

  1. One-component liquid adhesive composition, hardenable by visible light, having a viscosity of less than 25 MPa.s at 25 C, characterized in that it comprises   (a) 2 to 20 parts by weight of at least one phospho- ester   practically pure risk of formula CH2 = C (R) .CO.O.R.OP (O) (OH) in which R is a hydrogen atom or a methyl group   and R2 represents -CH2-CH2 -CH2-CH (CH3) - or -CH (CH3) -CH2- and   (b) 98 to 80 parts by weight of at least one non-monomer   ethylenic saturation copolymerizable with the phosphoric ester, and an effective amount of a catalyst activated by visible light.   2. Composition according to claim 1,   characterized in that R1 is a methyl group.   3. Composition according to claim 1 or 2,   characterized in that R2 is a propylene group.   4. Composition according to any one of   Claims 1 to 3, characterized in that the catalyst   activated by visible light contains an a-diketone.   5. Composition according to claim 4,   characterized in that the diketone is camphoquinone.   6. Composition according to any one of   Claims 1 to 5, characterized in that the catalyst   activated by visible light contains an organic tin compound. 7. Composition according to any one of   Claims 1 to 6, characterized in that the catalyst   activated by visible light contains an organic peroxide   fuck. 8. Composition according to any one of   claims 1 to 7, characterized in that the rate   impurity in the phosphoric ester is less than 2% in weight.   9. Composition according to any one of   claims 1 to 8, characterized in that the concentration   tion in phosphoric ester is 5% by weight or more.   10. Use of an adhesive composition   according to any one of claims 1 to 9,   characterized in that it consists in coating with   composition the surface of a tooth and to irradiate the compound   sition at room temperature with visible light   having a wavelength from 400 to 500 nm.