A polymerizable composition is formed from (a) a polymerizable olefinically unsaturated substance, (b) a phosphorus oxyacid and an organic amine, at least one of which bears a polymerizable olefinically unsaturated group and optionally (c) a particulate inorganic material. Such compositions are useful in dental applications.

This invention relates to polymerisable compositions. 
We have found that where an organic medium which comprises a polymerisable 
olefinically unsaturated substance is polymerised in contact with the 
surface of an inorganic material bonding of the polymerised organic medium 
to the surface may be improved by incorporating in the organic medium 
certain phosphorus oxyacids and certain amines as hereinafter defined. The 
inorganic material may be in the form of a coherent mass or a particulate 
material. Where the inorganic material is in particulate form and is 
suspended or dispersed in the organic medium the mechanical and physical 
properties, e.g. solvent resistance, of cured products prepared from such 
compositions are often better than those of similar composition described 
in European Patent Specification No. 0013491B. 
Accordingly, the present invention provides a polymerisable composition 
comprising: 
(a) an organic medium which comprises a polymerisable olefinically 
unsaturated substance which bears one or more polymerisable olefinically 
unsaturated groups; 
(b) a phosphorus oxyacid having the formula: 
##STR1## 
wherein R.sup.1 is a hydrocarbyl group or a polyether or polyester chain, 
R.sup.2 is hydrogen or a hydrocarbyl group or a 
polyether or polyester chain; and 
(c) an organic amine having the formula: 
##STR2## 
wherein R.sup.3 is a hydrocarbyl group or a polyether or polyester chain, 
and 
R.sup.4 and R.sup.5, which may be the same or different, are hydrogen, 
hydrocarbyl or polyether or polyester chains, 
except that at least one of the groups R.sup.1, R.sup.2, R.sup.3, R.sup.4 
and R.sup.5 comprises a polymerisable olefinically unsaturated group. 
As examples of polymerisable olefinically unsaturated substances of which 
polymerisable compositions according to the present invention are 
comprised and which contain one polymerisable olefinically unsaturated 
group may be mentioned readily available monomers selected from the 
classes including inter alia hydrocarbons, e.g. styrene; ethers, e.g. 
vinyl ethyl ether; esters, e.g. vinyl acetate, methyl methacrylate, ethyl 
acrylate, butyl methacrylate and 2-ethyhexyl methacrylate; and amides, 
e.g. N-vinyl pyrrolidone, and N-alkyl acrylamide. 
As examples of polymerisable olefinically unsaturated substances of which 
polymerisable compositions according to the present invention are 
comprised and which contain a plurality of polymerisable olefinically 
unsaturated groups may be mentioned inter alia the poly(alk)acrylate 
esters of, for example, diethylene glycol, trimethylolpropane and 
pentaerythritol, e.g. diethylene glycol dimethacrylate. 
Preferably polymerisable olefinically unsaturated substances of which 
polymerisable compositions according to the present invention are 
comprised are polymerisable prepolymers. As examples of such prepolymers 
may be mentioned vinyl urethanes, for example those described in United 
Kingdom Patent Specification Nos. 1,352,063, 1,465,097 and 1,498,421 and 
German Offenlegunsschrift No. 2,419,887; the reaction products of a diol, 
particularly a bisphenol, with a glycidyl alkacrylate, for example those 
described in U.S. patent specification Nos. 3066112 and 4131729; and the 
reaction products of an aromatic compound, formaldehyde and a 
polymerisable olefinically unsaturated carboxylic acid as described in our 
European patent application No. 83307128. The disclosures in the 
aforementioned specifications and application are incorporated herein by 
way of reference. 
Preferably the aforesaid polymerisable prepolymers are selected from the 
group consisting of vinyl urethanes as hereinbefore described which are 
the reaction products of a urethane prepolymer and a hydroxyalkyl ester of 
acrylic or methacrylic acid, the urethane prepolymer being the reaction 
product of a di-isocyanate of the structure OCN-R.sup.6 -NCO, where 
R.sup.6 is a divalent hydrocarbyl radical, preferably an alkylene radical 
having up to ten carbon atoms, e.g. hexamethylene, and a diol of the 
structure HO-R.sup.7 -OH, where R.sup.7 is the residue of a condensate of 
an alkylene oxide with an organic compound containing two phenolic or 
alcoholic groups; the aforesaid reaction products described in European 
patent application No. 83307128; and the reaction product of a glycidyl 
alkacrylate and a diol of the formula: 
##STR3## 
which polymerisable prepolymers are optionally in admixture with a 
polymerisable olefinically unsaturated monomer having one or more 
polymerisable olefinically unsaturated groups formed by esterifying 
acrylic or methacrylic acid with a hydroxy compound or a polyol, 
preferably a diol, e.g. triethylene glycol dimethacrylate. 
Where a group R.sup.1, R.sup.2, R.sup.3, R.sup.4 or R.sup.5 in phosphorus 
oxyacids and organic amines of which polymerisable compositions according 
to the present invention are comprised is a hydrocarbyl group it may be an 
alkyl, e.g. octyl; aralkyl, e.g. benzyl; alkaryl, e.g. tolyl; or aryl, 
e.g. phenyl, group. 
The groups R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 may carry 
substituents, which may be in-chain or pendant, which do not interact 
unduly adversely with the aforesaid surface of the inorganic solid nor 
unduly adversely affect the polymerisation of the polymerisable 
composition. As examples of such suitable substituents may be mentioned 
ester, hydroxy, halogen and ether groups. 
Preferably both the phosphorus oxyacid and the organic amine are 
polymerisable olefinically unsaturated compounds since use of such a 
mixture further improves the adhesion of the polymer prepared by 
polymerisation of the polymerisable compositions to the aforesaid surface 
of the inorganic material. 
Preferably at least one of the groups R.sup.1, R.sup.2, R.sup.3, R.sup.4 
and R.sup.5 and particularly preferably at least one of the groups R.sup.1 
and R.sup.2 and at least one of the groups R.sup.3, R.sup.4 and R.sup.5 
is, or is derived from, a hydrocarbyl group having at least six carbon 
atoms or a polyether, e.g. polypropylene oxide, or polyester chain, e.g. 
polycaprolactone of molecular weight greater than 200 and more 
particularly preferably is, or is derived from, a long chain alkyl group 
containing 8 to 22 carbon atoms or a polyether or polyester chain of 
molecular weight between 300 and 10,000. Use of a mixture of phosphorous 
oxyacid and organic amine wherein the groups R.sup.1, R.sup.2, R.sup.3, 
R.sup.4 and R.sup.5 are selected from these preferred definitions allows a 
greater concentration of particulate inorganic material to be dispersed in 
the organic medium and/or affords a decrease in the viscosity of the 
dispersion. 
As examples of polymerisable olefinically unsaturated groups which may be 
present in a phosphorus oxyacid or an organic amine of which polymerisable 
compositions according to the present invention are comprised may be 
mentioned inter alia (alk)-acroyloxyalkyl, and (alk)-acroylamidoalkyl, 
e.g. methacryloxypropyl, and acrylamidobutyl; allyl; residues of naturally 
occurring unsaturated acids, e.g. oleic acid; CH.sub.2 
.dbd.CH(CH.sub.2).sub.m --, where m is 6 to 50 e.g. undecenyl; CH.sub.2 
.dbd.CH--Ar--(CH.sub.2).sub.n --, where n is 6 to 50, CH.sub.2 
.dbd.CR.sup.8 COO(CH.sub.2).sub.p --, where R is hydrogen, methyl or ethyl 
and p is 6 to 50; and polybutadiene. It is often preferred that the 
polymerisable olefinically unsaturated group is distant the nitrogen or 
phosphorus atom. 
Whilst we do not exclude the possibility that phosphorus oxyacids of which 
polymerisable compositions according to the present invention are 
comprised may be in the form of a mono-ester or a mixture of mono- and 
di-esters, it is often preferred that a diester is present , preferably a 
diester in which both ester groups, which may be the same or different, 
contain a polymerisable olefinically unsaturated group. Conveniently, a 
mixture of phosphorous oxyacids may be used, typically a mixture of mono- 
and di-esters. 
As specific examples of phosphorus oxyacids of which polymerisable 
compositions according to the present invention may be comprised may be 
mentioned methacroyloxypropyl phosphate, di(methacroyloxypropyl) 
phosphate, oleyl dihydrogen phosphate, dioleyl hydrogen phosphate, 
di(undecenyl) phosphate, methacroyloxyhexyl phosphate, 
acroyloxypolypropoxyl phosphate, cholesteryl phosphate, and 
methacroyloxydodecyl phosphate. 
Whilst we do not exclude the possibility that organic amines of which 
polymerisable compositions according to the present invention are 
comprised may be primary amines, i.e. R.sup.3 and R.sup.4 are hydrogen, or 
secondary amines, i.e. R.sup.3 is hydrogen, preferably they are tertiary 
amines and more preferably each of the three substituent groups on the 
nitrogen contains polymerisable olefinically unsaturated group, which 
groups may be the same or different. 
As specific examples of organic amines of which polymerisable compositions 
according to the present invention may be comprised may be mentioned 
methacroyloxyethyl diethyl amine, di(methacroyloxyethyl) methylamine, 
olylamine, undecenylamine, methacroyloxypolypropoxyl amine, 
cholesterylamine, methacroyloxypropyl dimethylamine, 
tri(methacroylpolyoxypropyl)amine, dodecyl di(methacroyloxyethyl)amine. 
The organic medium used in a polymerisable composition according to the 
present invention should not contain acidic or basic groups. 
Polymerisable compositions according to the present invention may be used 
in the form of thin films. For example, they may be used for coating a 
substantially inorganic surface, e.g. as a corrosion resistant coating on 
a metal or as a glaze for teeth; or they may be used as adhesives, e.g. to 
bond a dental filling or cap into or onto a tooth cavity. 
However, in a preferred embodiment of the present invention the 
polymerisable composition as hereinbefore defined is in intimate admixture 
with a particulate inorganic material. Such compositions may be converted 
into substantially three-dimensional articles and objects or into coatings 
or films. 
A particulate inorganic material of which a polymerisable composition 
according to the present invention may be comprised may be any 
conventional particulate filler material, for example, metal oxides, e.g. 
alumina, titanium dioxide, magnetic iron oxide; carbon black; graphite; 
inorganic salts, e.g. hydroxy apatite; metals; clay and preferably is a 
siliceous material, for example silica and silicate-based glasses. 
Where a particulate inorganic material is present in a polymerisable 
composition according to the present invention and where it is a siliceous 
particulate material it may be, for example, a silicate salt, e.g. 
aluminium silicate or calcium silicate, or a silicate-containing mineral 
in finely divided form, e.g. talc, or preferably silica or a silicate 
based glass. Silica may be, for example, comminuted crystalline silica, 
e.g. sand, or preferably a colloidal silica, e.g. a pyrogenic or fumed 
silica, having particles of submicron dimensions. The silicate-based glass 
may be, for example, a borosilicate, which may contain small amounts of 
other so-called glass modifying oxides, e.g. barium oxide and strontium 
oxide. 
The particulate inorganic material may, for example, be in the form of 
spheres, platelets, fibres, whiskers or it may be irregularly shaped. 
It is preferred that at least 50% of the particles in the particulate 
inorganic material should have a maximum dimension of not greater than 50 
microns. By this is meant that the maximum dimension of the particles in 
any direction should not be greater than 50 microns. Thus, where the 
particulate inorganic material is in the form of spheres at least 50% of 
the spheres should have a diameter of not greater than 500 microns. Where 
the particulate inorganic material is in the form of fibres at least 50% 
of the fibres should have a length of not greater than 50 microns. 
Preferably substantially all of the particles in the particulate inorganic 
material have a maximum dimension of not greater than 50 microns. 
A polymerisable composition according to the present invention may comprise 
large quantities, for example up to 30-50% by volume and sometimes up to 
90% by volume, of a particulate inorganic material dispersed in the 
organic medium. Preferably a polymerisable composition according to the 
present invention comprises 20-70% by volume of a particulate inorganic 
material. 
Where a polymerisable composition according to the present invention 
comprises a particulate inorganic material moulded or cast articles for 
example, sheet, films, rods, tubes and especially articles moulded or cast 
into a variety of shapes having a specific utility for example handles, 
knobs, wheels, lids, sanitary ware, etc. or rubbery products e.g. tyres, 
shoe-soles, gloves may conveniently and advantageously be made from the 
aforesaid compositions. The particulate inorganic material often provides 
the finished article with a useful reinforcing, hardening or decorative 
effect or an increased resistance to solvent attack, or useful electrical 
properties. 
The concentrations of phosphorus oxyacid and organic amine in polymerisable 
compositions according to the present invention are not critical. For 
example, we have found that, where the polymerisable composition comprises 
a particulate inorganic material, noticeable results are obtainable when 
together they provide from 0.1% by weight and in general there is no 
further improvement above about 15% by weight relative to the weight of 
the particulate inorganic material. Typically about 5% by weight of the 
phosphorus oxyacid and the organic amine together relative to the weight 
of the particulate inorganic material is used. 
The molar ratio of phosphorus oxyacid to organic amine is typically between 
0.5:1 to 100:1 and preferably from 1:1 to 3:1. 
Preferably the organic medium is liquid at ambient temperatures because 
dispersion of the particulate inorganic material, where it is used, is 
more easily effected if no heating is required for liquifaction of the 
organic medium. However, we do not exclude the possibility that the 
organic medium may be a solid or semi-solid at ambient temperatures, the 
polymerisable composition may then be prepared at an elevated temperature 
above the melting point or softening point of the medium, which 
temperature should be below 250.degree. C. and preferably below 
150.degree. C. 
Polymerisation of polymerisable compositions according to the present 
invention may be initiated by a suitable free radical initiator system. 
Such initiator systems include azo systems, organic peroxides or 
preferably photo-initiator systems as described in United Kingdom Patent 
Specification No. 1408265 and European Patent Publication No. 59649A, the 
disclosures of which are incorporated herein be way of reference. 
Polymerisable compositions according to the present invention which contain 
a photo-initiating system, preferably a photo-initiating system which is 
activated by visible radiation, are particularly useful as dental 
compositions. 
Accordingly, a further aspect of the present invention provides a dental 
composition which comprises (a) a polymerisable prepolymer comprising a 
plurality of polymerisable olefinically unsaturated groups and being the 
reaction product of (i) a urethane and an olefinically unsaturated monomer 
reactive with the urethane or (ii) an aromatic compound, formaldehyde and 
an olefinically unsaturated carboxylic acid, (b) a phosphorus oxyacid as 
hereinbefore defined, (c) an organic amine as hereinbefore defined, (d) a 
free radical initiator system, preferably a photo-initiator system and 
optionally (e) a particulate inorganic material. 
Where a dental composition according to the present invention comprises a 
particulate inorganic material is is preferably a siliceous material as 
hereinbefore defined. 
It will be appreciated that a dental composition according to the present 
invention, where it contains a particulate siliceous material, has 
sufficient mobility that it may be readily moulded at ambient temperature, 
for example, by moulding under hand pressure. Conveniently, it will have a 
paste-like consistency. 
A dental composition according to the present invention where it comprises 
a particulate siliceous material may be applied to the tooth, e.g. as a 
filling to a cavity in the tooth, and may be polymerised so that the 
composition is formed into hard material. 
An dental composition according to the present invention which does not 
comprise a particulate inorganic material may be used as a dental glaze or 
adhesive. 
Where a polymerisable prepolymer of which a dental composition according to 
the present invention is comprised is a solid or semi-solid it is often 
necessary (in order to produce a dental composition which is fluid) to add 
to the composition sufficient of a liquid ethylenically unsaturated 
monomer copolymerisable with the polymerisable prepolymer to make the 
composition fluid, and in particular, where the composition comprises a 
particulate siliceous material, to give the composition a paste-like 
consistency. If desired, the composition may include a liquid 
copolymerisable ethylenically unsaturated monomer even where the 
polymerisable prepolymer is itself a liquid. 
The amount of such ethylenically unsaturated monomer used may desirably be 
just sufficient to achieve the desired fluidity in the dental composition. 
As the use of such amonomer may lead to a reduction in the strength of the 
dental filling made from the composition it is preferred to use in the 
composition not more than 100% of ethylenically unsaturated monomer by 
weight of polymerisable prepolymer, and more preferably not more than 50% 
by weight. 
Suitable liquid copolymerisable ethylenically unsaturated monomers, the 
polymers of which should be water insoluble, include vinyl monomers, e.g. 
esters of acrylic and methacrylic acids. Polyfunctional vinyl monomers, 
that is, monomers containing two or more vinyl groups are also suitable. 
Suitable monomers include, for example, glycol dimethacrylate, and 
triethylene glycol diacrylate. The monomers should be of low toxicity. 
In order that the cured dental composition should possess higher strength 
and modulus it is preferred that the polymerisable prepolymer possesses at 
least one cyclic group. It is preferred that the polymerisable prepolymers 
possess at least one cyclic group in the chain between the ethylenically 
unsaturated groups. 
Where dental compositions according to the present invention comprise a 
particulate siliceous material which is in the form of spheres, platelets 
or is irregularly shaped the maximum dimension of the particles in the 
particulate siliceous material is preferably not greater than 50 microns, 
and particularly preferably is not greater than 5 microns. 
A photo-initiator system for use in a dental composition according to the 
present invention preferably comprises at least one photo-sensitiser 
selected from fluorenone, substituted derivatives thereof, camphorquinone 
and .alpha.-diketones having the structure: 
##STR4## 
in which the groups A, which may be the same or different, are hydrocarbyl 
groups or substituted hydrocarbyl groups; and at least one reducing agent 
capable of reducing the photosensitiser when the photo-sensitiser is in an 
excited state, e.g. an amine. Preferably an organic peroxy compound, e.g. 
an organic peroxide, a peracid ester, or a hydroperoxide, is used in 
admixture with the photo-initiator system. 
The dental compositions of the present invention may be cured by 
irradiating the composition with ultra-violet radiation, that is, with 
radiation having a wavelength in the range about 230 m.mu. up to 400 
m.mu.. The compositions may also be, and preferably are, cured by 
irradiating with visible radiation and especially with visible radiation 
having a wavelength in the range 400 m.mu. to 500 m.mu.. Alternatively, a 
mixture of ultraviolet and visible radiation may be used. 
Suitably the concentration of the photosensitiser is 0.001% to 10% by 
weight, preferably 0.1% to 5% by weight and the concentration of reducing 
agent is 0.25% to 5% by weight preferably 0.25% to 0.75% by weight, all 
these percentages being by weight of the polymerisable material in the 
dental composition. 
Mixing of the polymerisable prepolymer with the particulate siliceous 
material to form a dental composition may be effected by stirring, or 
shearing, e.g. ball-milling together, the prepolymer and the filler. 
However, as the polymerisable prepolymer, optionally together with a 
copolymerisable monomer, may be viscous and thus difficult to stir with 
the particulate siliceous material so as to achieve adequate mixing the 
polymerisable prepolymer, optionally together with copolymerisable 
monomer, may conveniently be diluted with a suitable diluent so as to 
reduce the viscosity thus enabling adequate mixing of the particulate 
silicous material to be more readily achieved. When mixing has been 
effected the diluent may be removed, e.g. by evaporation. Suitably, the 
diluent may be a copolymerisable ethylenically unsaturated monomer, the 
concentration of the monomer subsequently being reduced to the desired 
extent. 
In order that a dental composition may be produced in which the particulate 
siliceous material in the composition adheres particularly well to the 
cured polymerisable prepolymer it is preferred that the particulate 
siliceous material be added to the mixture of polymerisable prepolymer, 
phosphorus oxyacid and organic amine. 
In order that a dental base and/or artificial tooth prepared from a dental 
composition according to the present invention may have flesh coloured 
and/or natural appearance, it may include small quantities of pigments, 
opalescent agents and the like. 
The dental compositions of the present invention may be used for a range of 
dental applications. For example, they may be used as filling materials 
(posterior and anterior), or for the preparation of individual artificial 
teeth. 
The dental composition of the present invention may conveniently be packed 
in small containers (e.g. 1 g capacity) so as to facilitate handling in 
the surgery and reduce the risk of inadvertent curing by stray light. 
The invention is illustrated by the following Examples.

EXAMPLES 1-3 
Dispersions of hydrophilic silica (Aerosil A130; "Aerosil" is a Registered 
Trade Mark of Degussa), 22% by weight, in methyl methacrylate containing a 
variety of dispersing agents were prepared by the procedure described in 
Example 1 of European Patent Specification No. 13491B and cured by the 
procedure described in Example 19 of the aforementioned specification. 
Various physical properties of the cured composites were measured. The 
results are shown in Table 1. 
TABLE 1 
______________________________________ 
Or- Phos- Flexural 
Flexural 
Impact 
Example 
ganic phorus Strength 
Modulus 
Strength 
No. Amine Acid MN/m.sup.2 
GN/m.sup.2 
Kg/cm.sup.2 
______________________________________ 
1 A C 64 3.7 4.2 
2 A D 76 4.2 5.0 
3 B D 73 4.0 4.7 
C.T. E C 60 3.7 2.5 
______________________________________ 
A is C.sub.12 H.sub.25 N(CH.sub.2 CH.sub.2 OH)CH.sub.2 CH.sub.2 
OOCCCH.sub.3 .dbd.CH.sub.2. 
B is C.sub.12 H.sub.25 N(CH.sub.2 CH.sub.2 OH)CH.sub.2 CH.sub.2 
OOCCH.dbd.CH.sub.2. 
C is di(2ethylhexyl)phosphoric acid. 
D is a 1:1 molar ratio mixture of the mono and diester obtained from the 
reaction of hydroxypropyl methacylate with phosphorus pentoxide. 
E is 90% octadecylamine (Armeen 18, ex AKZO). 
C.T is a comparative test. 
From the Table it can be seen that where the phosphorous oxyacid does not 
bear any polymerisable olefinically unsaturated groups use of an organic 
amine bearing a polymerisable olefinically unsaturated group (Example 1) 
produces better mechanical properties than use of an organic amine which 
does not bear a polymerisable olefinically unsaturated group (comparative 
test) and that where both the phosphorous oxyacid and the organic amine 
are polymerisable olefinically unsaturated compounds (Examples 2 and 3) 
further increases in mechanical properties are obtained. 
EXAMPLES 4-8 
Condensate (32.2 grams; 0.1 mole) obtained by reacting 
2,2-bis-(4-hydroxyphenyl) propane and propylene oxide in a molar ratio of 
1:2(oxypropylated bisphenol A) was dissolved in approximately 100 grams of 
methylene dichloride and the resulting solution was added dropwise to a 
solution of hexamethylene diisocyanate 33.6 g (0.2 mole) in methylene 
dichloride (100 g) under an atmosphere of nitrogen gas. 4 drops of dibutyl 
tin dilaurate (available as "Mellite" 12, "Mellite" is a registered trade 
mark) were added as catalyst. The mixture was stirred under nitrogen for 1 
hour after which it was heated under reflux conditions for 9 hours. The 
mixture was then cooled and a solution of hydroxypropyl methacrylate 29 g 
(0.2 mole) in methylene dichloride (100 g) was added after which the 
mixture was heated under reflux conditions for 3 hours. The hydroxypropyl 
ester comprised isomers in weight ration 2-hydroxypropyl (2.6 parts) to 
1-methyl-2-hydroxyethyl (1 part). To the mixture of vinyl urethane 
(polymerisable prepolymer) and methylene chloride was added triethylene 
glycol dimethacrylate sufficient to produce polymerisable material 
containing 50% by weight vinyl urethane and 50% by weight of triethylene 
glycol dimethacrylate. The methylene chloride was removed by distillation. 
A photosensitive catalyst system comprising camphorquinone, and 
dimethylaminoethyl methacrylate was prepared by dissolving the components 
in methylene chloride. The solution was added to the polymerisable 
material; this and subsequent steps being carried out under sodium 
discharge light. 
The camphorquinone concentration was 0.75%, and the dimethylaminoethyl 
methacrylate concentration was 0.5% by weight based on polymerisable 
material. 
A phosphorus oxyacid and an organic amine followed by a particulate 
inorganic material were added to the polymerisable composition and 
photosensitive catalyst system. The mixture was milled on a twin-roll mill 
operating at ambient temperature under reduced pressure. 
Samples of the products from the twin-roll mill were placed in moulds (25 
mm.times.2 mm.times.2 mm) and cured by exposure for 60 seconds to light of 
intensity 110-1200 Wm.sup.-2 measured at 470 m.mu.. The cured samples were 
aged for 24 hours at 37.degree. C. and then their flexural properties were 
determined in a three-point bend test with the supports 20 mm apart and a 
cross-head speed of 1.0.+-.0.05 mm/min. 
Details of the polymerisable compositions and the flexural properties of 
the products are given in Table 2. 
TABLE 2 
______________________________________ 
Polymerisable Composition 
Properties 
Particulate of Product 
Ex- Inorganic Phosphorus 
Organic 
Flexural 
Flexural 
ample Material Oxyacid Amine Modulus 
Strength 
No. (%).sup.a (%).sup.b (%).sup.b 
(GPa) (MPa) 
______________________________________ 
4 F(43) J(1.45) P(1.17) 
7.79 84.5 
C.T./4 
F(43) K(1.33) P(1.17) 
7.08 63.2 
5 G(50) L(1.64) P(1.17) 
8.77 56.3 
C.T./5 
G(50) K(1.33) P(1.17) 
7.10 47.5 
6 H(50) M(3.20) P(1.17) 
5.78 39.0 
C.T./6 
H(50) K(1.33) P(1.17) 
5.19 37.8 
7 I(50) K(1.33) Q(4.8) 2.78 20.2 
8 I(50) N(1.0) Q(4.8) 4.17 28.4 
______________________________________ 
F: Fumed Silica (Grade OX50 ex Degussa). 
G: Borosilicate glass (2-20 microns). 
H: A barium containing glass (Raysorb T3000). 
I: Hydroxyapatite. 
J: A phosphorus oxyacid derived from 1,6dihydroxyhexane and methacrylic 
acid. 
K: Di2-ethylhexyl phosphoric acid. 
L: A phosphorus oxyacid derived from triethylene glycol and methacrylic 
acid. 
M: A phosphorus oxyacid derived from polypropylene glycol (MW 400) and 
methacrylic acid. 
N: Undecenyl phosphate. 
P: A mixture of C.sub.12 H.sub.25, C.sub.13 H.sub.29 and C.sub.14 H.sub.2 
NMe.sub.2 (ex Albright and Wilson) 
Q: CH.sub.2 .dbd.CCH.sub.3 CO.sub.2 (CHCH.sub.3 CH.sub.2 O).sub.n CH.sub. 
CH.sub.2 N(CH.sub.3).sub.2 where n is about 14. 
.sup.a Percentage by volume of polymerisable composition. 
.sup.b Percentage by weight based on the weight of particulate inorganic 
material. 
CT/4, CT/5 and CT/6 are comparative tests. 
The phosphorus oxyacids designated J, L, and M in Table 2 were prepared as 
follows. A solution of methacroyl chloride (0.66 moles) in methylene 
chloride (100 grams) was added dropwise over 30 minutes to a solution of 
the apropriate diol (0.66 moles) and pyridine (0.73 moles) in methylene 
chloride (200 grams.) The reaction mixture was stirred at room temperature 
for 2 hours and then refluxed for 3 hours. The reaction mixture was washed 
with dilute HCl solution, pyridine chloride was removed by filtration and 
the filtrate was washed with aqueous sodium bicarbonate solution. 
Phosphorus pentoxide (0.44 moles) was then added to the filtrate with 
stirring over 1 hour and the reaction mixture was refluxed for 3 hours. It 
was washed with aqueous sodium bicarbonate solution, then with water, 
filtered and the solvent was removed on a rotary evaporator. 
The organic amine designated Q in Table 2 was prepared by reacting 
N,N-dimethylaminoethylpolypropylene glycol in an inert solvent with a 
small molar excess of pyridine and a small molar excess of methacroyl 
chloride.