JPH02296874A - Surface-treated inorganic powder - Google Patents

Abstract

PURPOSE:To provide an inorg. powder excellent in the dispersibility and useful as a filler for a resin by choosing an inorg. powder contg. a metallic element coated with a specific organophosphorus compd. CONSTITUTION:An inorg. powder (e.g. Al2O3 powder) contg. a metallic element surface-coated with an organophosphorus compd. of formula I [wherein R1 is H or CH3; X1 is O or S; X2 and X3 are each hydroxyl, mercapto, or halogen; Y1 is -COO-, -COS-, or a group of formula II (wherein R2 is H or 1-6C hydrocarbon) group; Y2 is X1 or a group of formula III; n is 8-40; and l is 0 or 1] (e.g. a compd. of formula IV) is chosen.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a surface-treated inorganic powder. For more information,
It is an inorganic powder containing a metal element whose surface has been treated with an organic phosphorus compound having a polymerizable double bond. These are used as fillers for resins, and are useful as fillers for various molding materials, coating agents, adhesives, electromagnetic shielding agents, dental materials, plastic surgery materials, and the like.

(Prior Art and Problems to be Solved by the Invention) In order to compound an inorganic powder with a resin material, the surface of the powder needs to be organically treated. Silane coupling agents are extremely effective and widely used as surface treatment agents for silica powder, but they are not suitable for surface treatment of inorganic powders that contain metal elements such as metals and their oxides, carbonates, and sulfates. Poor effect. On the other hand, it is known that organic phosphate ester compounds are effective for these powders.

Japanese Patent Publication No. 6G-3431 describes an inorganic filler surface-treated with the following organic phosphate ester.

(However, R1 in the above formula is hydrogen or a methyl group, R.

is an alkylene group having 2 to 6 carbon atoms or a halogen-substituted derivative thereof, or a polyoxyethylene group -CHf-CHl
(-0-cHt-CHl square, (n=1~20), and (
n=1 to 20). ) Inorganic powder whose surface has been modified with a type I or 2N or higher organic phosphorus compound treatment agent selected from the group (4,
R and R" are the same or different alkyl, alkenyl, aryl, alkoxy, alkenoxy, and aryloxy groups each having 1 to 30 carbon atoms, and each of these organic groups has a substituent.

In addition to these, JP-A-56=54795, JP-A-57
Similar techniques are described in JP-A No. 128728, JP-A-57-LAG9S4, JP-A-57-198735, and the like.

However, if composite materials are molded using inorganic fillers using these known surface treatment techniques, they may have poor mechanical strength or may be used for applications that require particularly severe water resistance, such as dental composite resins. When used as a filler in composite materials that are exposed outdoors for long periods of time, the adhesion between the filler and the resin matrix deteriorates over time, so it is necessary to develop a surface treatment technology for inorganic fillers that exceeds the technology in the above-mentioned literature. This is an important issue.

(Means for Solving the Problem) In order to achieve the above object, the present inventors investigated the relationship between the molecular structure and the surface treatment effect of various organic phosphorus compounds, and found that they have a specific molecular structure. The present inventors have discovered that the desired surface treatment effect can be obtained with organic phosphorus compounds, and have completed the present invention.

That is, the present invention relates to a phosphorus compound represented by the following general formula (where R1 is a hydrogen atom or a methyl group, xl is an oxygen atom or a sulfur atom, and X and X are a hydrohydrogen atom or represents a hydrocarbon group having 1 to 6 carbon atoms), Y represents an oxygen atom, a sulfur atom, or R1N-, n represents an integer of 8 to 40, and Q represents O or 1]. It is an inorganic powder containing a metal element whose surface has been treated with the organic phosphorus compound shown below.

The inorganic powder of the present invention is characterized by containing a metallic element, and the metallic element referred to in the present invention is an element located to the left of the line connecting boron and ascutin in the long periodic table. Yes, except for hydrogen and the elements on this line, B, Si, As1Te, and At. Among these metals, A12, for example, is particularly useful.
Mg5C11% Ti%Cr, Fe, Co.

! 1iSCu%Zn%5rSZrs Pds Hg
Examples include s Sns Ba1Ptq AL1%La.

These metal elements can exist in various forms in the inorganic powder. For example, the most common All
! 's, ZnO1CaO1Ties, ZrO*, La*
Including oxides such as Os, Bad, Fe*Oi, 5rOt, etc., oxides such as A12 (Oll), halides such as CaFt, or Ba5Oi
and sulfates such as Ca5Oa, carbonates such as CaC01, CaHPO, Ca(HtPOa)*, Ca5(P
Oa)t, CatP, Ot, Ca(POs)*, Ca
aPtOs, MgOP401t, A(2(POs)*
, ACPO, etc., in the form of various salts such as phosphates.

In addition to cases where these metal compounds exist as a single component in inorganic powder, there are also ceramics that are multi-component systems,
It may be a mineral type. In the case of a multi-component system, there are not only multiple metal elements, but also components other than metal elements, e.g.
For example, 5ift, ptos.

It is also permissible to contain B, 03.5L3N4, SiC, B, C%B11, etc. Examples of these include KtO
・Tie,,Ba04i0t,Ca(lAI2'tos
, zircon (SiO*-ZrOt series), sialon (5
10m kQ*Os 5sN4 system), La glass ceramics (La1Os A12*03Sift system, e.g. 5hott GM 31-684■), B
a glass (BaO-Aff, O, -BaO3-5ins
system, for example 5hott GM 27-884■, 5
hott 8235■, Ray-5orb T-2
000■, Ray-5orb T-3000@)
, Sr glass (SrO*-A12tOs-5ift system, e.g. 5hott GM 32-0870, Ra
y-5orb T-40000), various CaO-PtOs-containing crystallized glasses known as bioglasses, and hydroxyapatite.

Furthermore, in addition to these forms, the metal itself may be used as a powder. In this case, the metal may be used alone or as an alloy.

Note that when the inorganic powder comes into contact with water or is used in a high humidity environment, it is essential that it is insoluble in water. In the present invention, insolubility is defined as solubility with a saturated solubility in water at room temperature of 0.1% by weight or less.

There are no restrictions on the shape of these inorganic powders, and various shapes and sizes, such as spherical, crushed, acicular, whisker, and plate-like shapes, can be selected depending on the purpose. Further, the particle size of these inorganic powders is not particularly limited, but those in the range of 5n- to 0.5am are preferably used. Note that the particle size here refers to the average value of the maximum diameter and minimum diameter of the powder particles of ta.

The greatest feature of the present invention lies in the molecular structure of the organic phosphorus compound [11] used as a surface treatment agent. That is, a methacryloyl group which is a polymerizable group and inorganic powder Table X.

■ 1P-X that can react with the surface, the group is a straight chain X with 8 to 40 carbon atoms! The point is that they are connected through a ``alkylene group''.

The number of carbon atoms in the alkylene group affects the mechanical strength and water resistance of the composite resin composition filled with the inorganic powder of the present invention, and when a compound having 8 to 40 carbon atoms is used, the mechanical strength and its water resistance are affected. It has been found that a composite resin composition with excellent water resistance can be obtained.

In addition, organic phosphorus compounds [! ] Even if surface treatment is performed using a compound having a chemical structure with the methacryloyl group removed, the adhesion between the powder and organic rat ll11 is poor;
The purpose of the invention is not achieved at all.

Among the compounds represented by the general formula [11], those particularly preferably used in the present invention from the viewpoint of reactivity with the inorganic powder surface, ease of synthesis, etc. will be described below.

First, phosphoric acid compounds in which X is an oxygen atom and both X and X are hydroxyl groups are preferable, and are the most effective compound group when the inorganic powder contains a base metal element. It is. An example of a base metal element is A11%
Mg, Ca, Tt%Fe%Cos Crs Ni.

Cu, ln, 5r1Zr, S n s B a s
Examples include L a N Cr, etc., and special AI! 102,
Metal oxides such as Tie, ZrO, Fetus, ZnO, CaCO5, Caa(POa)*, A12PO,
metal salts such as hydroxyapatite, and Ti%F
It is highly effective against metal powders containing es Cos Cr, Ni%Cu%Zn, etc.

Specific examples of this group of compounds are shown below.

? 1° 1 HmC-CC00BHthO-P OHO! -1, C= C-C00BH, ), 0- P-Cf
2OH Next, in the formula [1], xl is an oxygen atom and X, and X.

Examples include halides of phosphoric acid in which both are represented by halogen atoms such as chlorine atoms or bromine atoms. Like the aforementioned compound group, this compound exhibits an excellent surface treatment effect on powders containing base metal elements. A specific example is shown below.

Examples include OH Co O l 1 H*C= C-C00BHth OP CQ. Among these, ■ r Next, thiophosphoric acid or its derivatives in which xl is a sulfur atom and X2 and Shows excellent surface treatment effects against the inorganic fillers it contains. Examples of precious metals here include Pd, Ag, and Pt.

It exists as a tautomer with

Specific compounds are shown below.

Cl13 S H*C=C-COO←H,), 0- P-0)1〼OH C)l, SLC=CC00
kHth. Examples include 0-P-OHOH Au. Moreover, in these compounds -P
-x, as a specific example of the group,
Q CH3, S H*C= CCoo((:Hw)ioOP CQCQ 11tL;= L; -L;υsu(t11t?+oU
t' btlH CH, S l 1 H□c= c-cos←Xh square,. 5-P-3H amount R CHs SH* C= C
Coo((l: H1 sho, .O-P-SHH The synthesis method for these organophosphoric acid compounds is Organop
hosphorus Compound (G, M,
Kosola'poH7F, l1ley11950
), Organophosphorus Monome
rs and Polymers (Ye, L, G
by erLer, Pregamon Press 196
2), Modern Organic Synthesis Series 5, Organophosphorus Compounds (edited by the Organic Synthetic Chemistry Association, Gihodo, 1971) Be1lst
ein (Springer-Verlag) etc. can be referred to.

More specifically, JP-A-58-128393 and JP-A-58-192891. JP 58-21687, JP 58-21688, JP 59-139392, JP 59-135272, JP 59-142268, JP 60-166363, JP 60-166364,
Synthesis methods disclosed in Japanese Patent Application Laid-Open No. 57-151607 and the like can be used.

The compound represented by the above general formula [1] [hereinafter referred to as compound [
! A method of treating the surface of an inorganic powder containing a metal element [hereinafter sometimes referred to as inorganic powder [A]] using a surface treatment agent is The treatment can be carried out using generally known methods, and can be roughly divided into wet methods and dry methods.

In the wet method, the inorganic powder [A] and the compound [11] are suspended in a slurry form in an appropriate amount of a solvent such as water, alcohol, hexane, benzene, toluene, xylene, etc., and thoroughly stirred.

However, the optimal values for conditions such as the solvent used, reaction temperature, and reaction time vary depending on the combination of inorganic powder [A] and compound [1], but those skilled in the field can easily find them. obtain. After stirring for a predetermined period of time, the solvent is removed by distillation under reduced pressure, J-filtration, freeze drying, or the like to complete the surface treatment.

In this case, it is desirable to include a heating step in any of the processing steps. Heating is performed using inorganic powder [A, compound [
! ] and the solvent while stirring the slurry, or while the solvent is being distilled off. In some cases, the solvent may be further heated after distillation. In particular, when the powder is heated in a suspended state with a solvent, the dispersibility is improved and the powder surface is evenly treated. The heating temperature is preferably in the range of 50°C to 150°C, and if it is lower than 50°C, the heating effect will be poor.
If the temperature exceeds 150°C, there is a possibility that the polymerizable double bond will react.

Also, the compound [! The above-mentioned wet treatment method may be carried out using an alkali metal salt, ammonium salt, etc., and then reacted with the inorganic surface in a desalting reaction.

In the dry method, the inorganic powder [A] is placed in a mixer such as a Henschel mixer or a ribbon blender, and the compound [1] is mixed with stirring.
1 is added as is or diluted with an appropriate solvent and added by spraying. At this time, it is desirable to stir while heating. This method is suitable for processing large amounts of powder.

In any of the above treatment methods, the amount of compound [11] used for inorganic powder [A] is at least the amount that can cover most of the surface of inorganic powder [A] with a monomolecular film of compound [1]. preferable. This amount can be estimated from the value of the specific surface area of the inorganic powder [A] measured by the BET method or the like. For example, the smaller the particle size of the inorganic powder [A], the more the required amount of the compound [1] increases. In the present invention, 0.01 to 0.01 to part of LQQlffi of inorganic powder [A]
IQQ executive section is used. However, the optimum amount of compound [11 to be used is determined based on experiments so that the desired physical properties of the resulting composition are maximized.

In addition, the amount of the compound [1] attached to the inorganic powder [A] is
Elemental analysis and infrared analysis of surface-treated inorganic powder [A]
It can be estimated by fluorescent X-ray analysis.

By the way, BaOlLaw's, Al1. O,, CaO
In the case of glasses, ceramics, and crystallized glass powders containing silica (Sins) in metal oxides such as 1SrOt and Ti01ZrOt, many silanol groups derived from the silica component are present on the surface thereof. When an organic phosphorus compound [1] is used for surface treatment of such an inorganic filler, it has a surface treatment effect on metal elements, but it has a poor effect on silanol groups, so desired results cannot be obtained. . For glass fillers with high silica content, organic phosphorus compounds [! ] It is desirable to use a known silane coupling agent, such as γ-methacryloyloxypropyltrimethoxysilane, in combination.

In such a case, a two-step treatment method is adopted in which the surface treatment of the present invention is first performed and then the surface treatment is performed again using a silane coupling agent.

As a modified method, a method in which the surface treatment of the present invention is performed after treatment with a silane coupling agent, or a method in which a one-step treatment is performed by mixing an organic phosphorus compound [11] and a silane coupling agent are possible.

The inorganic powder of the present invention surface-modified by the method described above is used as a filler for resins.

Examples of resins used for this purpose include polyolefin resins such as polyethylene, polypropylene, polystyrene, and polyvinyl chloride, and general thermoplastic resins such as polyester, polyamide, polyacetal, and ABS resin. In this case, the resin is brought into a molten state using a conventional kneader, and then the inorganic powder of the present invention is added, kneaded, and molded.

Furthermore, the inorganic powder of the present invention is kneaded with a polymerizable monomer as a resin to provide a polymerizable composition.

The polymerizable monomer used in this case is appropriately selected depending on the use of the composition, but the compound used as a surface treatment agent [
1], and usually a (meth)acrylate monomer [the expression (meth)acrylate means both methacrylate and acrylate] is used.

In addition to these, esters with monohydric or dihydric alcohols such as α-anoacrylic acid, crotonic acid, cinnamic acid, sorbic acid, maleic acid, and itaconic acid, and (meth)acrylamides such as N-isobutylacrylamide, Vinyl esters of carboxylic acids such as vinyl acetate, vinyl ethers such as butyl vinyl ether,
A coating using mono-N-vinyl compounds such as N-vinylpyrrolidone, styrene derivatives, etc.

An example of a (meth)acrylate monomer is methyl (
meth)acrylate, lauryl(meth)acrylate,
Monofunctional (meth)acrylates such as dimethylaminoethyl (meth)acrylate, triethylene glycol di(
meth)acrylate, 1, IO-decanediol di(meth)acrylate, vinyl ethers (meth)acrylate, 2.2-bis[(meth)acryloyloxypolyethoxyphenyl]propane, 2.2-bis[4- (3
- bifunctional (meth)acrylates such as -methacryloxy-2-hydroxypropoxy) phenylcopropane (sometimes referred to as Bit-GMA), trifunctional (meth)acrylates such as trimethylolpropane tri(meth)acrylate, penta Examples of tetrafunctional (meth)acrylates include erythritol tetra(meth)acrylate and an adduct of 1 mol of 2,2.4-)dimethylhexamethylene diisocyanate and 2 mols of glycerin di(meth)acrylate. These monofunctional and polyfunctional (
The meth)acrylates may be used alone or in a mixture of 2N or more.

In such a composition, the mixing ratio of the surface-modified inorganic powder [A] and the resin varies greatly depending on the application, but usually the surface-modified inorganic powder [A] is mixed with 1 part by weight of the resin.
A] ranges from 0.01 parts by weight to 100 parts by weight.

Furthermore, in addition to the inorganic powder [A], other powders may be added to the composition as necessary.

The powder may be either inorganic or organic, and examples of the inorganic powder include inorganic powders containing silica as a main component, such as quartz, amorphous silica, and borosilicate glass. These powders are used after being subjected to surface treatment in advance with a silane coupling agent. On the other hand, examples of organic powders include polymer powders such as polymethyl methacrylate, polyvinyl chloride, and polystyrene, and organic-inorganic composite powders as disclosed in JP-A-56-49311.

When a polymerizable monomer is used as the resin, the above composition can be polymerized and cured by heating it to a temperature of 100°C or higher or by applying external energy such as irradiation with an electron beam. It can be converted into processed products, but
Polymerization and curing are often facilitated by adding a polymerization initiator.

The polymerization initiator used in such a case is not particularly limited and may be any known initiator, but it is usually selected in consideration of the polymerizability of the polymerizable monomer and the polymerization conditions. For example, when thermally polymerizing (meth)acrylate, organic peroxides such as benzoyl peroxide (referred to as BPO) and cumene hydroperoxide, and compounds such as 2,2-azobisisobutyronitrile are preferably used. It will be done.

On the other hand, when performing room temperature polymerization, in addition to oxidation-reduction initiators such as benzoyl peroxide/dimethylaniline, organic sulfinic acid (or its salt)/amine/peroxide, tributylborane, organic sulfinic acid, etc. etc. are also suitably used.

On the other hand, when photopolymerization is performed by irradiation with visible light, α
Preferred are oxidation-reduction systems such as -diketone/tertiary amine, α-diketone/aldehyde, α-diketone/mercaptan. α-diketones include camphorquinone, 2.
Tertiary amines such as 3-pentanedione and benzyl include N,N-dimethylaminoethyl methacrylate and I
Examples of aldehydes include lauryl aldehyde and p-octyloxybenzaldehyde, and examples of mercaptans include thiosalicylic acid and 2-mercaptobenzoxazole. Furthermore, an α-diketone/organic peroxide/reducing agent system in which an organic peroxide is added to these oxidation-reduction systems is also preferably used.

In the case of photopolymerization by ultraviolet irradiation, 2.4.6-drimethylbenzoyldiphenylphosphine oxide,
In addition to benzoin methyl ether, benzyl dimethyl ketal, 2-methylthioxanthone, and the like, the above visible light photopolymerization initiators are also suitably used.

The appropriate amount of these polymerization initiators added is in the range of 0.01 to 10% based on the polymerizable monomer.

(Examples) Next, the present invention will be explained by examples, but the present invention is not limited to these examples.

Example 1 Alumina (Showa Denko, A L-160s (1;
-4 [F] 50g 1 toluene 200g 1g and lO-
3 g of methacryloyloxydecyl dihydrodiene phosphate was placed in a flask and heated under reflux for 2 hours with vigorous stirring. After cooling, the alumina powder was separated from the suspension in a furnace, thoroughly washed with toluene, vacuum-dried for 12 hours, and further heated in air at 90°C for 2 hours to obtain surface-treated alumina powder ( Filler A) was obtained. The phosphorus content of this powder was determined by fluorescent X-ray analysis and the absorption heat of IO-methacryloyloxydecyl dihydrogen phosphate was estimated.
The amount was 1.2 parts by weight per 00 parts by weight. In addition, the diffuse reflection FT infrared absorption spectrum of the powder was measured, and the difference spectra before and after the surface treatment were found, and a peak derived from the carbonyl group of the methacrylic group was found at 1720 cm-'.
Peaks derived from C-H bonds were observed at 920 cm-' and 2850 cm-', confirming that the above compound was adsorbed on the powder surface.

Example 2 35 parts by weight of 2.2-bis[methacryloyloxyboriethoquinphenylcopropane (having an average of 26 ethoxy groups in the molecule), 1 mol of 2,2.4-trimethylhexamethyleneneusonanate 40 parts by weight of an adduct with 2 moles of glycerin dimethacrylate, 25 parts by weight of neopentyl glycol dimethacrylate, and 1 part by weight of 1M benzoyl peroxide were mixed to obtain a polymerizable monomer composition. 30 parts by weight of this composition and Example! Filler A obtained in
70 parts by weight were mixed and kneaded to obtain a polymerizable resin composition (paste).

The following evaluations were performed using this composition.

(i) Consistency A filler that has good wettability with the polymerizable monomer has excellent dispersibility in the polymerizable monomer and has a soft viscosity. Therefore, by measuring the consistency as an index of viscosity, it is possible to judge whether the surface treatment is good or bad. In this experiment, the value measured by the following method was defined as the consistency.

That is, 0.5a+12 of the paste was weighed out and placed in a heap at the center of a glass plate (5 x 5c+s). Next, a glass plate (sx 5ca) with a load of 40 g was gently placed on top of it, and after 120 seconds, the long axis and short axis of the spread paste were measured through the glass plate.
The arithmetic mean value of both was defined as the consistency.

The values are shown in Table 1 and are the average of three repeated measurements.

(11) Bending strength The bending strength was measured as an index of the adhesive strength between the polymerized and cured resin matrix and the filler.

First, the paste was put into a 2×2×30 m5 mold, heated at 130° C. for 1 hour to harden it, and then taken out from the mold to obtain a prismatic test piece. This test piece was stored in air at 37°C for one day, and then subjected to a three-point bending test using an Instron universal testing machine (distance between both end supports = 20s+e).
, crosshead speed = 1111/5 in). The results shown in Table 1 are the average values of 10 measurements.

(Mountain) Water resistance in bending strength For water resistant materials, maintaining mechanical strength under wet conditions is the most important issue. The bending test piece prepared according to the procedure in Section 11 was immersed in water at 70° C. for 10 days to accelerate deterioration, and then the bending strength was measured. By comparing with the initial bending strength described in Section 11, it is possible to judge whether the water resistance is good or bad. The average values of the 10 test pieces are shown in Table 1.

Examples 3 to 12 Alumina powders were surface-treated in the same manner as in Example 1 using the compounds shown in Table 1 instead of the compounds used in Example 1.

Example of the alumina powder! In a similar manner, alumina 1
Measure the amount of organic phosphorus compound attached per 00 parts by weight,
Further, a resin composition was prepared according to the method of Example 2, and its consistency and bending strength were evaluated, and the results are shown in Table 1.

Comparative example! Example! The same composition as in Example 2 was prepared using the alumina powder used in Example 2 as a filler without surface treatment, and its consistency and bending strength were evaluated. The results are shown in Table 2.

Comparative Examples 2 to 6 Alumina powder was surface-treated using the compounds shown in Table 2 according to the method of Example 1. The same composition as in Example 2 was prepared using the alumina powder, and its consistency and bending strength were evaluated. The results are shown in Table 2.

Below are blank examples +3 Average particle size 0.02 μs+, BET specific surface area Laos”/
g (7) Flumina fine powder (aluminum oxide C
1 Nippon Aerosil) 50g, Example 1 as a surface treatment agent
15g of the same organic phosphorus compound and 500s of toluene12
The suspension was heated under reflux at 110°C for 3 hours. After cooling, the powder was collected by centrifugation, vacuum dried for 24 hours, and then heat treated in air at 90° C. for 2 hours to obtain a surface-treated alumina fine powder (referred to as filler B).

Elemental analysis of this powder revealed that the natural content was 85.5% by weight, and therefore 14.5% by weight of the surface treatment agent was adsorbed on the powder surface.

Example 14 100 g of ffi powder (3oo mesh pass), 1 g of a compound represented by the following structural formula (10-methacryloyloxydecyl dichlorothiophosphate) as a surface treatment agent, and toluene loOm
No. 12 was placed in a flask and subjected to the same operation as in Example 1 to obtain surface-treated silver powder.

Examples 15 to 21 Inorganic powders of the types shown in Table 3 were subjected to surface treatment under the conditions of Example 1. The consistency and bending strength of the composition obtained by kneading the obtained powder and the polymerizable monomer composition prepared in Example 2 at the ratio shown in Table 3 were measured according to the method of Example 2, The results are shown in Table 3.

Comparative Examples 7-13 Compositions corresponding to Examples 13-19 were prepared using inorganic powders of the types shown in Table 3 without surface treatment, and their consistency and bending strength were measured according to the method of Example 2. The results are shown in Table 3.

The following margin Example 20 La-glass ceramics manufactured by Shott (GM-31
H4) was ground with a vibrating ball mill and the particle size ranged from 0.1 to
A powder of 20 μm and an average particle size of 2.8 μm was obtained. A glass filler (referred to as filler C) was obtained by subjecting 100 parts by weight of the powder to surface treatment using 2 parts by weight of 7-methacryloxypropyltrimethoxysilane according to a conventional method.

On the other hand, the same polymerizable monomer composition as in Example 2 (not containing benzoyl peroxide) was prepared, and 0.0% per 100 parts by weight was prepared.
A polymerizable composition was obtained by adding 5 parts by weight of 2.4.6-trimethylbenzoyldiphenylphosphine oxide as a photopolymerization initiator. Example 134 filler 8180 parts by weight and filler 0500 parts by weight of the composition too weight 11f@
Parts by weight were kneaded to obtain a photocurable resin composition. The composition was cured by irradiating it with xenon lamp light (Dentacolor
The flexural strength, compressive strength and Brinell hardness of the cured product which was heated at c for 30 minutes to complete polymerization were measured, and the results are shown in Table 4.

stomach. In particular, if radically polymerizable monomers are used in resins, it is possible to obtain dental restorative materials with high strength.

(Effects of the Invention) The surface-treated inorganic powder of the present invention has been surface-treated more effectively than conventional known techniques, and has excellent dispersibility when kneaded into a resin.

In addition, at this time, the viscosity increasing effect is suppressed to a lower level than in the conventional technology, especially when the powder is ultrafine particles of 0.1μ or less.
It is now possible to knead more densely.

The resin composition filled with the inorganic powder of the present invention has excellent mechanical strength and abrasion resistance, and is characterized by little deterioration in performance, especially under humid conditions.

Claims (1)

[Claims] General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [I] [However, R_1 is a hydrogen atom or a methyl group, X_1 is an oxygen atom or a sulfur atom, X_2 and X_3 are a hydroxyl group, a mercapto group, or represents a halogen atom, Y_1 represents -COO-, -COS- or ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (R_2 represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms), and Y_2 represents A metal element surface-treated with an oxygen atom, a sulfur atom, or an organic phosphorus compound represented by ▲ (there are mathematical formulas, chemical formulas, tables, etc.), n is an integer from 8 to 40, and l is 0 or 1) Inorganic powder containing.