JPH0782125A - Cleaning agent containing hydroxyapatite - Google Patents

Abstract

PURPOSE:To provide a new cleaning agent effectively usable for cleaning tooth surface, containing, as abrasive ingredients, two kinds of hydroxyapatite differing in particle diameter from each other. CONSTITUTION:The objective cleaning agent containing, as abrasive ingredients, hydroxyapatite X 100-300mum in the maximum diameter and hydroxyapatite Y<=2mum in the maximum diameter. The above two kinds of hydroxyapatite X and Y are each at least one kind of amorphous hydroxyapatite baked or unbaked, independent of each other. In particular, the hydroxyapatite X, being high in hardness, is pref. of baked form, being pref. amorphous among others. The amounts of the hydroxyapatite X and hydroxyapatite Y to be contained are pref. 5-50 pts.wt. and 0.1-40 pts.wt. per 100 pts.wt. of the final cleaning agent. This cleaning agent preferably contains 30-60 pts.wt. of propylene glycol as humectant and 10-35 pts.wt. of polyvinylpyrrolidone having 500000-4000000 weight-average molecular weight as binder each per 100 pts.wt. of the final cleaning agent. This cleaning agent is useful for cleaning tooth surface.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cleaning agent containing hydroxyapatite. More specifically, a hydroxyapatite structure, a cleaning agent for teeth, etc., and a film formed from an emulsion of an emulsion polymer containing a sulfonic acid group, a multivalent cation-containing adherend such as a hydroxyapatite structure, a tooth, The present invention relates to a cleaning agent when applied as a sealant for dentin hypersensitivity.

[0002]

2. Description of the Related Art Conventionally, various cleaning agents have been proposed for cleaning and polishing a hydroxyapatite structure such as teeth. The direct bonding system (DBS) in orthodontic treatment requires efficient removal of organic coatings such as pellicle on the tooth surface in a short time before etching the enamel with acid. However, if you use a cleaning agent with low viscosity, the cleaning agent will scatter during cleaning,
Problems such as complicated operation and uneconomical are pointed out. Further, an aluminum hydroxide having a particle size of 10 to 40 μm as a polishing component, propylene glycol as a moisturizing agent, carboxymethyl cellulose as a binder, and a dental paste containing paraben and monosulfonic acid as other components.
When the strike is used as a cleaning agent, the enamel is less damaged, but an organic film remains on the cleaning and polishing surface, and cleaning in a short time is difficult. The remaining organic coating lowers the efficiency of the acid etching that is performed next, making it difficult to firmly bond the tooth substance and the resin. Further, in an ad nest having diatomaceous earth having a particle size of 30 to 80 μm as a polishing component, glycerin as a moisturizing agent, polyvinylpyrrolidone as a binder, etc., the organic film is removed,
Various problems such as damage to the enamel due to the difference in hardness between the polishing component and the enamel remain (about the adhesion to human enamel and the tooth surface cleaning effect Yasuo Saito,
Kunitaka Hotta, Yasuo Okamoto, Fujio Miura, Nobuo Nakabayashi Journal of the Japan Society for Adhesive Dentistry, vol9 No. 4 272-277 (199
1)). Furthermore, with a cleaning agent containing crushed hydroxyapatite having a particle size of 100 to 200 μm as a polishing component, polyvinylpyrrolidone as a binder, and propylene glycol as a moisturizer, damage to the enamel can be suppressed as much as possible (human enamel cleaning. Effect of Phosphoric Acid Concentration on Adhesion to Polished Surface Yasuo Saito, Kunitaka Horita, Kunimichi Soma, Nobuo Nakabayashi Dental Materials and Instruments vol12 No.12 418-423 (1
No. 993) has poor storage stability, and the polishing component and the dispersant are separated from each other, and it is necessary to knead them again before use. In this way, for cleaning and polishing of hydroxyapatite structure such as teeth,
It is very important not only to remove the organic film efficiently in a short time, but also to prevent damage to the cleaning surface from the viewpoint of protecting the tooth structure. Further, in order to finish the time required for cleaning in a short time, not only the cleaning efficiency is excellent, but also the storage stability of the cleaning agent is very important.

[0003] Further, in the case of cleaning a hypersensitive dentin surface in which dentinal tubules are exposed in the affected area of the tooth, especially in the oral cavity, damage to the tooth material during cleaning and polishing alone induces pain. There is a fear and you should avoid it as much as possible.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel cleaning agent containing hydroxyapatite that solves the above problems. Another object of the present invention is to provide a film formed from an emulsion of an emulsion polymer containing (meth) acrylic acid ester units previously proposed by the present applicant, to a hydroxyapatite structure, especially a dentin hypersensitivity side film. -When applied as a sealant, it provides a cleaning agent that does not damage the affected area, can efficiently remove only dirt such as an organic coating, and has the function of improving the sealing ability of the sealant for tubules. Especially. Still another object of the present invention is to provide a cleaning agent which does not separate the polishing component and other dispersion components and has extremely excellent storage safety. Further objects and advantages of the present invention will be apparent from the following description.

[0005]

According to the present invention, the above objects and advantages of the present invention are as follows.
μm hydroxyapatite (X) and longest diameter is 2μ
This is achieved by a cleaning agent containing hydroxyapatite (Y) of m or less as a polishing component. Here, (X) and (Y) are, independently of each other, at least one kind of hydroxyapatite that is a fired body or an unfired amorphous body, and its shape is not limited, such as an amorphous shape and a spherical shape.
Since (X) has high hardness, a fired body is preferable, and an amorphous type is particularly preferable.

As the weight of the polishing component, it is preferable to contain 5 to 50 parts by weight of the component (X) and 0.1 to 40 parts by weight of the component (Y) per 100 parts by weight of the cleaning agent.

Propylene glycol is preferred as the moisturizing agent for the above polishing component, and polyvinylpyrrolidone is preferred as the binder. The weight average molecular weight of polyvinylpyrrolidone is preferably 500,000 to 4,000,000.

Further, it is preferable to contain 30 to 60 parts by weight of propylene glycol and 10 to 35 parts by weight of polyvinylpyrrolidone per 100 parts by weight of the cleaning agent.

By using the cleaning agent of the present invention, it becomes possible to remove stains such as an organic film in a short time without damaging the hydroxyapatite structure, the tooth substance and the like. Further, since the scattering of the cleaning agent at the time of cleaning can be reduced, the cleaning efficiency can be improved.

Further, since the cleaning agent of the present invention contains hydroxyapatite (Y) having a maximum diameter of 2 μm or less, the dentinal tubule opening (diameter of about 2 μm) is removed together with the removal of stains when cleaning the dentin hypersensitivity surface. It also has a function of closing or filling with (Y). Therefore, from (a) a vinyl compound having a repeating unit derived from (meth) acrylic acid ester and (b) a group —SO ₃ R (wherein R represents a hydrogen atom, an alkali metal atom or an ammonium ion). In addition to the emulsion polymer composed of the repeating unit derived or the repeating units of the above (a) and (b), further (c) the group —COOR ₄ or the group —OPO (OR ₅ )
A film formed from an emulsion of an emulsion polymer composed of repeating units derived from a vinyl compound having ₂ (wherein R ₄ and R ₅ represent a hydrogen atom, an alkali metal atom or an ammonium ion) is coated with a polyvalent cation. When applied as a sealant, especially as a dentin sealant with hyperesthesia, a sulfonic acid group which is a constituent of the emulsion polymer,
Since it reacts with the hydroxyapatite (B) that closes or fills the dentinal tubules, it has a feature that the tubule-blocking property of the formed film is improved as compared with when the cleaning agent of the present invention is not used. .

Next, the cleaning agent containing the hydroxyapatite of the present invention will be specifically described. As a polishing component, a hydroxyapatite (X) having a maximum diameter of 100 μm to 300 μm and a hydroxyapatite (Y) having a maximum diameter of 2 μm or less are contained as polishing components. here,
The hydroxyapatite of (X) is preferably a fired product having high hardness because it needs to be cleaned and polished in a short time, and particularly preferably an amorphous type. The hydroxyapatite (Y) may be calcined hydroxyapatite or uncalcined amorphous hydroxyapatite, and contains at least one kind of these hydroxyapatite. Further, (Y) may have any shape such as an amorphous shape and a spherical shape, but the amorphous shape is preferable. The longest diameter means the diameter of the maximum length regardless of whether the particles are spherical or not. The weight part of (X) in 100 parts by weight of the cleaning agent is preferably in the range of 5 to 50 parts by weight, more preferably 10 to 40 parts by weight, and particularly preferably 20 to 35 parts by weight. Moreover, the weight part of (Y) is preferably in the range of 0.1 to 40 weight parts, more preferably 5 to 35 weight parts, and 10 to 30 weight parts.
Part by weight is especially preferred. Here, (Y) is tubule blockage,
Not only the effect of blocking, but also the effect of preventing the separation of the polishing component and the dispersant. In addition to the hydroxyapatite, a commonly used polishing component can be added within a range that does not impair the characteristics of the cleaning agent of the present invention. As the polishing component, for example, dibasic calcium phosphate, tricalcium phosphate,
Phosphate compounds such as aluminum phosphate and zinc phosphate, carbonate compounds such as calcium carbonate, magnesium carbonate, magnesium calcium carbonate and barium carbonate, hydroxides such as aluminum hydroxide, calcium hydroxide and magnesium hydroxide, insoluble sodium metaphosphate, meta Examples thereof include metaphosphate compounds such as potassium phosphate and sodium metaphosphate, and minerals such as diatomaceous earth, bentonite, and silicon oxide.

The moisturizing agent for the polishing component is not particularly limited as long as it gives the polishing component moistness and viscosity, but propylene glycol is particularly preferable. The amount of propylene glycol added is preferably 3 per 100 parts by weight of the cleaning agent.
It is in the range of 0 to 60 parts by weight, more preferably 40 to 5
5 parts by weight, particularly preferably 45 to 55 parts by weight. In addition to propylene glycol, glycols such as ethylene glycol, diethylene glycol and triethylene glycol, glycerin, sorbitol, etc., within the range that does not impair the characteristics of the present cleaning agent. Alcohols such as ethanol and methanol, water and the like can be added.

Any binder can be used without limitation as long as it imparts plasticity to the cleaning agent, but polyvinylpyrrolidone is particularly preferable. As the molecular weight of polyvinylpyrrolidone, the weight average molecular weight is preferably in the range of 500,000 to 4,000,000, more preferably 2,000,000 to 4,000,000, and particularly preferably 3,000,000 to 4,000,000. The amount of polyvinylpyrrolidone added is preferably in the range of 10 to 35 parts by weight, more preferably 1 part by weight per 100 parts by weight of the cleaning agent.
5 to 30 parts by weight, particularly preferably 15 to 25 parts by weight. Besides polyvinylpyrrolidone, for example, gum arabic, tokagant gum, alginic acid, carboxymethylcellulose (C
MC), polyvinyl alcohol, water-soluble acrylic resin and the like can be added.

In addition to the above components, foaming detergents such as sodium lauryl sulfate, sodium laurate, and alkylacryl sulfonic acid, and fragrances such as sorbitol and 1-menthol, as long as the characteristics of the cleaning agent are not impaired,
Colorant, preservative to prevent corrosion on the inner surface of the container, zinc oxide,
Polishing agents such as alumina, fluorides such as sodium fluoride, stannous fluoride, sodium fluorophosphate, bactericides,
There is no problem even if drugs such as anti-inflammatory agents and antibiotics are added.

Further, a film formed from an emulsion of an emulsion polymer containing a (meth) acrylic acid ester unit previously proposed by the present applicant is used to form an adherend containing a polyvalent cation such as a hydroxyapatite structure, particularly a dentinal tube opening. When used as a sealant for the surface of dentin hypersensitivity associated with the exposure of the surface (diameter of about 2 μm) in the oral cavity, using the above emulsion having a particle size extremely smaller than the opening diameter causes Since the emulsion particles easily flow in, there is a possibility that a sealing material having an insufficient capillary blockability is formed.

However, when the cleaning agent of the present invention is used for cleaning and polishing the surface of sensitized dentin, hydroxyapatite (Y) having a maximum diameter of 2 μm or less clogs or fills the thin tube portion, which makes it easier for emulsion particles to flow. It is possible to eliminate the defective portion of the seal material, and to form the seal material, which is firmly adhered by the reaction between the sulfone group which is a constituent component of the emulsion particles and (Y), on the original capillary opening surface. It is possible to improve the tube sealing performance.

The emulsion of the emulsion polymer containing the (meth) acrylic acid ester unit used here is the emulsion previously proposed by the present applicant. That is,
(A) A repeating unit derived from a (meth) acrylic acid ester and a repeating unit derived from a vinyl compound having (b) a group —SO3R (wherein R represents a hydrogen atom, an alkali metal atom or an ammonium ion). And (c) a group —COOR ₄ or a group —OPO (OR ₅ ) ₂ (wherein R ₄ and R ₅ are hydrogen atoms,
It is an emulsion of an emulsion polymer comprising repeating units derived from a vinyl compound having an alkali metal atom or ammonium ion). .

The emulsion polymer emulsion used in the present invention contains the above-mentioned emulsion polymer as an emulsifier (meta).
Also included are emulsions of emulsion polymers obtained by emulsion polymerization of acrylic acid esters.

The repeating unit derived from the above (a) (meth) acrylic acid ester is, for example, the following formula (A):

[0020]

[Chemical 1]

A unit represented by the formula (wherein R ₁ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ₂ is an alkyl group having 1 to 5 carbon atoms) is preferable.

Examples of the repeating unit derived from the vinyl compound having the group —SO ₃ R (b) include compounds represented by the following formula (B):

[0023]

[Chemical 2]

A unit represented by the formula (wherein R ₃ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R is selected from the group consisting of a hydrogen atom, an alkali metal atom and an ammonium ion) is preferred.

The method for producing the emulsion polymer emulsion according to the present invention is represented by the following formula (R):

[0026]

[Chemical 3]

(Here, the definitions of R ₁ and R ₂ are the same as those in the above formula (A).) And the (meth) acrylic acid ester represented by the following formula (S).

[0028]

[Chemical 4]

(Here, the definitions of R ₃ and R are the same as those in the above formula (B).) And a sulfo group-containing monomer represented by the formula (B) is emulsified in a molar ratio of 99: 1 to 50:50. Polymerization is carried out, or the emulsion polymer thus obtained is used as an emulsifier to homopolymerize the (meth) acrylic acid ester monomer represented by the above formula (R) or to copolymerize two or more thereof. To be done.

Further, the vinyl compounds represented by the above formulas (R) and (S) are added to the (E) group --COOR ₄ or the (F) group --OPO (OR ₅ ) ₂ (wherein R ₄ and R ₅ Has the same definition as above) and a molar ratio of (R) to (S) + (E) or (S) + (F) is 99:
1 to 50:50 and emulsion polymerization is carried out within a molar ratio of (S) to (E) or (F) of 99: 1 to 1:99, or the emulsion polymer thus obtained is It is also carried out by using as an emulsifier, homopolymerizing the (meth) acrylic acid ester monomer represented by the above formula (R) or copolymerizing two or more kinds thereof.

Next, a method for producing an emulsion of the emulsion polymer used in the present invention will be described.

The emulsion polymer emulsion of the present invention (hereinafter referred to as "EM") is represented by the above formula (R) (meta).
Acrylic ester and a vinyl compound represented by the above formula (S) having a group —SO ₃ R (R represents a hydrogen atom, an alkali metal atom or an ammonium ion) are prepared by a known emulsion polymerization method (for example, Polymer latex, Soichi Muroi, Ikuo Morino, New Polymer Collection).

In the formula (R), R ₁ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. R ₁ is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group.

R ₂ is an alkyl group having 1 to 5 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. R ₂ is preferably a methyl group, an ethyl group or a butyl group, and particularly preferably a methyl group.

Preferred examples of the compound represented by the above formula (R) include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate,
Propyl (meth) acrylate, pentyl (meth) acrylate, glycidyl (meth) acrylate, 2-hydroxy (meth) acrylate, 3-hydroxy (meth)
Mention may be made of (meth) acrylic acid esters such as acrylate. Among these, methyl methacrylate
, Ethyl methacrylate and butyl methacrylate are preferred, and methyl methacrylate is particularly preferred.

Another monomer used in the present invention
Is a monomer having a group —SO ₃ R (R represents a hydrogen atom, an alkali metal atom or an ammonium ion). Specific examples of such a vinyl compound include, for example, a vinyl compound or a vinyl compound substituted with an alkyl group or the like, a group —SO ₃ R (the definition of R is the same as above).
Can be directly or indirectly bonded via another group.

Preferred examples of such sulfonic acid group-containing monomers are allyl sulfonic acid, methallyl sulfonic acid, vinyl sulfonic acid, o-styrene sulfonic acid,
m-styrene sulfonic acid, p-styrene sulfonic acid, t
Examples thereof include ert-butyl acrylamide sulfonic acid, and alkali metal salts such as lithium salt, potassium salt and sodium salt of these compounds, or ammonium salt. Among these, a compound in which the group —SO ₃ R is indirectly bonded to a carbon atom constituting a polymerizable group, for example, styrenesulfonic acid is preferable. Preferable examples of such a compound include the compounds represented by the above formula (S).

In the above formula (S), R ₃ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group,
Mention may be made of pentyl groups. It is particularly preferable that R ₃ is a hydrogen atom.

The group -SO ₃ R is the o-position of the benzene ring, m-
It may be bonded to any position of p-position or p-position. Considering the adhesion to the adherend, the p-position is preferable. The group —SO ₃ R may also be a lithium salt, potassium salt, sodium salt or ammonium salt. Preferred examples of the compound represented by the above formula (S) include allyl sulfonic acid, methallyl sulfonic acid, vinyl sulfonic acid, sulfoethyl methacrylate, tert.
Examples include sulfonic acid compounds such as -butyl acrylamide sulfonic acid and p-styrene sulfonic acid, and their sodium salts and ammonium salts. Among these, p-styrene sulfonic acid is particularly preferable.

As the monomer having the group (-E) -COOR ₄ (R ₄ represents a hydrogen atom, an alkali metal atom or an ammonium ion), acrylic acid, methacrylic acid, vinyl acetic acid, crotonic acid, methacryloyloxybenzoic acid can be used. Unsaturated monovalent carboxylic acids such as acids, vinylsalicylic acid and vinylacetylsalicylic acid, and their alkali metal salts or ammonium salt compounds, maleic acid,
Fumaric acid, itaconic acid, aconitic acid, citraconic acid,
Mention may be made of unsaturated polyvalent carboxylic acids such as mesaconic acid and 4-methacryloyloxyethyl trimellitic acid, and their alkali metal or ammonium salt compounds. Of these, acrylic acid and methacrylic acid are preferred.

The group -OPO (0R ₅ ) ₂ (R ₅
Is a hydrogen atom, an alkali metal atom or an ammonium ion), and acid phosphoethyl (meth) acrylate, 3-chloro-2-acid phosphopropyl (meth) acrylate, and acid phosphooxyethylene Glycol monomethacrylate, acid phosphooxypropyl (meth) acrylate, acid phosphooxypolyoxyethyl ethylene glycol mono (meth) acrylate, acid phosphooxypolyoxypropylene glycol mono (meth) acrylate Examples thereof include phosphoric acid ester monomers such as glutamine and the like or monomers having an alkali metal salt or ammonium salt thereof. Among them, acid phosphooxyethyl methacrylate or acid phosphooxyethylene glycol monomethacrylate is useful. Moreover, group -OPO (0R _{5) 2} (the definition of R ₅ are the same as above), within a range not to impair the properties of the emulsion of the emulsion polymer, may be OR ₅ substituent other than described above. For example, 2- (meth) acryloyloxyethyl phenylphosphoric acid, 2- (meth) acryloyloxyethyl 4
Phosphoric acid such as -methoxyphenyl phosphoric acid, 2- (meth) acryloyloxyethylbenzyl phosphoric acid, 2- (meth) acryloyloxyethylmethyl phosphoric acid, 2- (meth) acryloyloxyethylethyl phosphoric acid, 2- (meth) acryloyloxyethyl phosphoric acid Ester type monomers can be mentioned.

In the emulsion polymerization, the molar ratio of the monomer represented by the above formula (R) to the monomer represented by the above formula (S) is preferably within the range of 99: 1 to 50:50, and more preferably. Is in the range of 95: 5 to 60:40. Further, a monomer represented by the above formula (R) and a monomer represented by (S), and a vinyl compound having a (E) group —COOR ₄ or a (F) group —OPO (OR ₅ ) ₂ (here And the vinyl compound having R ₄ and R ₅ is the same as the above), (R) vs. (S) + (E) or (S) +
The molar ratio of (F) is 99: 1 to 50:50 and (S)
It is preferable that the molar ratio of (E) or (F) is within the range of 99: 1 to 1:99, and (R) to (S) + (E).
Alternatively, the molar ratio of (S) + (F) is 95: 5 to 60:40.
And the molar ratio of (S) to (E) or (F) is in the range of 99: 1 to 5:95 is more preferable.

The reaction conditions for emulsion polymerization are not particularly limited,
Monomers (R) and (S) within the range of room temperature to 100 ° C,
Or (R) and (S) + (E) or (S) + (F)
60 parts by weight or less with respect to 100 parts by weight of water, an initiator usually used in emulsion polymerization is added, and these are polymerized in the range of several tens of minutes to 24 hours to obtain a good emulsion polymer. Emulsions can be produced. Here, if the monomer mixture is added all at once, an emulsion with a large amount of aggregates tends to be generated, so it is preferable to add the monomer mixture intermittently.

In emulsion polymerization, even if a surfactant such as a polymeric surfactant such as an anionic surfactant, a cationic surfactant, a nonionic surfactant, or polyethylene glycol is added during the production of the emulsion, Although no problem, it is possible to produce an emulsion polymer emulsion having a diameter of 1 μm or less, which has a very small amount of coagulation even in a non-added state and has high stability in water. For the purpose of simplifying the post-treatment and not impairing the adhesiveness and film strength of the emulsion polymer emulsion, it is preferable to carry out the soap-free emulsion polymerization without using a surfactant. Further, when the above-mentioned monomer (E) or (F) is used, the stability of the emulsion is affected by the acidity, and therefore it is preferable to produce it under acidic conditions of pH = 6 or less.

In addition to the above-mentioned monomers, for example, N- (2-hydroxy-3-methacryloyloxypropyl) -N- in addition to the above-mentioned monomers, as long as the characteristics of the adhesive latex are not impaired.
Phenylglycine, glycidyl (meth) acrylate,
Glycidyl esters such as N-allylglycine: N,
(Meth) acrylic acid esters having an alkylamino group such as N-dimethylaminoethyl (meth) acrylate, aminoethyl (meth) acrylate, hydroxyethylaminoethyl (meth) acrylate, ethylene, propylene, butene -1, such as olefins; vinyl chloride,
Vinylidene chloride, vinyl bromide, (meth) acrylic acid 2-
Chloroethyl ester, 1,1-dichloroethylene,
Vinyl halides such as 1,2-dichloroethylene and tetrachloroethylene; vinyl esters such as vinyl acetate and vinyl propionate; methyl vinyl ether, isobutyl vinyl ether, (meth) acryl aldehyde diacetate, (meth) acryl aldehyde Vinyl acetate such as diethyl acetate 1,2-dimethoxyethylene
Ternes; alkenylbenzenes such as styrene, vinyltoluene, α-methylstyrene, chloromethylstyrene, stilbene, 1,1-diphenylethylene; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; (meth) acrylaldehyde, 3 -(Meth) acrylaldehydes such as cyano (meth) acrylaldehyde; (meth) acrylamide, N-vinylphthalamide, N-vinylsuccinamide, N, N-dimethylacrylamide, N-hydroxymethyl (meth) acrylamide, Acrylic acid amides such as N-hydroxyethyl-2-methylacrylamide; hydroxyl groups such as hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate ( Meta Monomer capable of normal emulsion polymerization such as acrylic acid esters - can also be copolymerized.

Next, a method for producing an emulsion polymer obtained by homopolymerization or copolymerization of (meth) acrylic acid ester (S) using the thus obtained emulsion polymer emulsion "EM" as an emulsifier explain. The (meth) acrylic acid ester used here is a compound represented by the above formula (R). Also in this case, in the formula (R), specific examples of the alkyl group represented by R ₁ and R ₂ include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. R ₁ is preferably an alkyl group, and particularly preferably a methyl group. Further, R ₂ is preferably a methyl group.

In this case, preferred examples of the compound represented by the formula (R) include methyl (meth) acrylate,
An alkyl ester of (meth) acrylic acid such as ethyl (meth) acrylate, butyl (meth) acrylate, propyl (meth) acrylate, pentyl (meth) acrylate, glycidyl (meth) acrylate, etc. Can be mentioned. Of these, methyl methacrylate is particularly preferable.

The emulsion polymerization method of the (meth) acrylic acid ester represented by the above formula (R) is characterized by using the emulsion polymer emulsion "EM" described in detail above as an emulsifier. The emulsion polymer emulsion "EM" used here may be added once again as an emulsifier after being taken out from the reaction kettle, or after the emulsion polymer emulsion "EM" is produced, the formula ( It is also possible to add (meth) acrylic acid ester compound represented by R) and perform emulsion polymerization.

The reaction conditions are not particularly limited. For example, after the emulsion polymer emulsion "EM" is produced, the reaction is performed at room temperature to 100%.
By adding the (meth) acrylic acid ester compound represented by (R) within the temperature range of ℃, several tens of minutes to 2
An emulsion polymer emulsion can be produced by emulsion polymerization within the range of 4 hours. The mixing ratio of the emulsion polymer emulsion "EM" and the monomer represented by (R) and the mixing amount with respect to water are not particularly limited. Preferably "EM" :( R) is 1: 99-
The weight ratio is 80:20, and the total amount of "EM" and the monomer (R) mixed is preferably 60 parts by weight or less with respect to 100 parts by weight of water. The type of the (meth) acrylic acid ester compound represented by the formula (R) and the composition of the mixture in the polymerization system are intermittently changed to carry out the emulsion polymerization to obtain the type of the emulsion polymer and the composition of the copolymer. It is also possible to change.

In addition to the compound of the above formula (R), the above-mentioned emulsion polymer emulsion is within a range that does not impair the adhesiveness, film strength and the like of the emulsion polymer emulsion of the present invention.
Other monomers can be copolymerized. Examples of such copolymerizable monomers include N- (2
-Hydroxy-3-methacryloyloxypropyl)-
N-phenylglycine, glycidyl (meth) acrylate
And glycidyl esters such as N-allylglycine:
N, N-dimethylaminoethyl (meth) acrylate,
(Meth) acrylic acid esters having an alkylamino group such as aminoethyl (meth) acrylate and hydroxyethylaminoethyl (meth) acrylate, ethylene,
Olefin such as propylene and butene-1; vinyl chloride, vinylidene chloride, vinyl bromide, (meth) acrylic acid 2-chloroethyl ester, 1,1-dichloroethylene, 1,2-dichloroethylene, tetrachloroethylene and other halogenated vinyls; Vinyl esters such as vinyl acetate and vinyl propionate; methyl vinyl ether,
Vinyl ethers such as isobutyl vinyl ether, (meth) acrylaldehyde diacetate, (meth) acrylaldehyde diethyl acetal 1,2-dimethoxyethylene; styrene, vinyltoluene, α-methylstyrene, chloro Methylstyrene, stilbene, 1,1-
Alkenylbenzenes such as diphenylethylene; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; (meth) acrylaldehydes such as (meth) acrylaldehyde and 3-cyano (meth) acrylaldehyde; (meth) acrylamide, N- Acrylic amides such as vinylphthalamide, N-vinylsuccinamide, N, N-dimethylacrylamide, N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl-2-methylacrylamide; hydroxymethyl (meth) acrylate 2-hydroxyethyl (meth)
Examples thereof include monomers that are usually emulsion-polymerizable such as (meth) acrylic acid esters having a hydroxyl group such as acrylate and 4-hydroxybutyl (meth) acrylate.

A polyvalent cation-containing adherend capable of reacting the emulsion of the above-mentioned emulsion polymer with a sulfonic acid group such as a hydroxyapatite structure, for example, an adhesive sealant on the surface of dentin or hypersensitivity dentin. When used as
It is preferably used in a state of being dispersed in a polar solvent such as water or ethanol. Especially when it is used for dentistry, it is preferably dispersed in water or a water-ethanol mixed medium before use. The solid content weight of the emulsion polymer emulsion in such a dispersion solvent is preferably 0.0
5 to 20 parts by weight, more preferably 1 to 15 parts by weight, and particularly preferably 3 to 8 parts by weight.

If desired, the emulsion of the emulsion polymer may contain various known additives. Examples of such additives include color pigments, extender pigments,
Wetting agents, bone agents, thickeners and the like can be mentioned.

[0053]

EXAMPLES Examples of the present invention will now be specifically described, but the present invention should not be construed as being limited thereto.

The effect of the cleaning agent of the present invention prepared from the following components and compositions will be described. (X) Amorphous (crushed) type fired hydroxyapatite (longest diameter 100 to 200 μm; manufactured by Asahi Optical Co., Ltd.): 23 parts by weight, (Y) Amorphous amorphous hydroxyapatite (longest diameter is 0.1 μm of amorphous hydroxyapatite) Aggregate aggregated to 4 μm; manufactured by Asahi Optical Co., Ltd .:
23 parts by weight, propylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.): 38 parts by weight, polyvinylpyrrolidone (weight average molecular weight 3.6 million; manufactured by Daiichi Pure Chemicals Co., Ltd.): 16 parts by weight ).

Example 1 A brush cone (manufactured by Tagaya Seisakusho) attached to an electric engine (manufactured by Tokyo Engine Co., Ltd.) was attached with 0.1 g of NPA, and the human enamel surface was cleaned and polished for 5 seconds at a speed of 3000 rpm, and then for 10 seconds. It was washed with water and dried. No scattering of cleaning agent occurred during cleaning. Scanning electron microscope (JSM-5
When the cleaned surface was observed with an acceleration voltage of 10 kV with a 400 type, manufactured by JEOL, hereinafter referred to as SEM), almost no remnants such as an organic film and surface scratches due to cleaning and polishing were observed. The SEM photograph is shown in FIG.

Further, after etching with a 65% phosphoric acid aqueous solution for 30 seconds, the enamel pillars can be clearly observed.
It was confirmed that the organic coating was completely removed by A cleaning. A SEM photograph of the etched surface is shown in FIG.

Comparative Example 1 Human enamel surface was cleaned and polished under the same conditions as in Example 1 using adnes (polishing component: diatomaceous earth, other components: glycerin, polyvinylpyrrolidone, etc.) as a cleaning agent. Scattering of cleaning agent was observed during cleaning. Almost all the remnants on the surface were removed, but linear scratches were widely observed on the surface.

Comparative Example 2 Dental paste (polishing component: aluminum hydroxide, other components: sorbit, propylene glycol, CMC)
Etc.) as a cleaning agent, and cleaning and polishing were performed under the same conditions as in Example 1. Scattering of cleaning agent was observed during cleaning. Remnants of an organic film were found on the surface, and shallow scratches were also observed. That SE
The M photograph is shown in FIG.

Further, when etching, an unclear portion of the enamel pillars was observed, which indicates that the organic coating was not completely removed. The SEM photograph is shown in FIG.

Freshly extracted bovine teeth were ground to # 600 with water-resistant emery paper under water injection to expose dentin. Next, 0.1 g of the cleaning agent containing the hydroxyapatite was applied to the ground surface of the brush cone, polished for 30 seconds with an electric engine at a speed of 3000 rpm, washed with water for 10 seconds and dried.
Next, the polished bovine tooth was ultrasonically washed in water for 30 minutes (UL TRASONIC CLEANER, manufactured by Kaneda Rikagaku Kogyo Co., Ltd.). From the SEM observation, the grinding debris (smear plug) that had blocked the dentinal tubules was removed and the tubules were completely open. The bovine tooth surface (hereinafter referred to as Z surface) obtained by the polishing and ultrasonic cleaning was used as a model surface of dentin hypersensitivity induced by the exposure of the dentin tubule to the inside of the oral cavity. . SEM of Z surface
The photograph is shown in FIG.

Example 2 A Blush cone (manufactured by Tagaya Seisakusho) attached to an electric engine (manufactured by Tokyo Engine Co., Ltd.) was attached with 0.1 g of NPA, and the Z surface prepared by the method described above was cleaned at a speed of 3000 rpm for 5 seconds. After polishing, it was washed with water for 10 seconds and dried.
No scattering of cleaning agent occurred during cleaning. When the surface was observed by SEM, all the capillaries were filled with hydroxyapatite (Y) and were closed. FIG. 6 shows an SEM photograph of the NPA cleaned and polished surface.

Comparative Example 3 A cleaning agent obtained by removing hydroxyapatite (Y) from an NPN cleaning agent {X (30 wt%) / propylene glycol (49 wt%) / polyvinylpyrrolidone (21 wt%)} was used, and Example 2 was used. The Z surface was cleaned and polished under the same conditions as above. S
From EM observation, no blocking or filling of dentinal tubules was observed.
Had a similar image to.

Example 3 50 ml of distilled water was heated to 60 ° C., and argon gas was bubbled for 20 minutes. Methyl methacrylate purified by distillation under an argon gas atmosphere (2.0 g, hereinafter MMA
), Sodium styrene sulfonate (0.54
g), potassium persulfate (30 mg) and sodium sulfite (10 mg) were added, and the mixture was vigorously stirred at 60 ° C. for 2.5 hours. MMA (1.0 g), potassium persulfate (15 m
g) and sodium sulfite (7 mg) were added 4 times at intervals of 30 minutes, followed by vigorous stirring for 19.5 hours. After cooling to room temperature, concentrated hydrochloric acid (0.19 ml) was added, the mixture was stirred for 2 hours, placed in a dialysis tube, and distilled water was exchanged every day for 5 days, and dialysis was repeated. The tube was dried at room temperature and atmospheric pressure to obtain an emulsion having a solid content of 10.9 wt%.
From the elemental analysis, the MMA unit content of this emulsion polymer was 9
It was 6.9 mol%. From the SEM observation, the emulsion particle size was 0.05 to 0.1 μm. The emulsion of the emulsion polymer thus obtained was prepared at a concentration of 5 wt%. The dentinal tubule shown in Example 2 was applied to the surface blocked with hydroxyapatite (FIG. 6), left for 30 seconds, and then dried with compressed air to form a film. Rinse with water for 1 minute,
After applying ultrasonic waves in water for 35 minutes, SEM observation was performed. The dentinal tubule was closed, and the surface layer part was also covered with a film formed from an emulsion of an emulsion polymer. The SEM photograph is shown in FIG.

Comparative Example 4 The same operation as in Example 3 was performed using the Z surface (FIG. 5) in which the dentinal tubules were opened. There were some areas where the ivory tubules were blocked, but there were many areas where the tubules were open. The SEM photograph is shown in FIG.

Comparative Example 5 50 ml of distilled water was heated to 60.degree.
Bubbling for 0 minutes. Sodium lauryl sulfate (250 mg) was added under an argon gas atmosphere, and the mixture was stirred for 10 minutes. Distilled MMA (10 g), potassium persulfate (100 mg) and sodium sulfite (10 mg) were added, and the mixture was polymerized for 5 hours. After cooling to room temperature, it was placed in a dialysis tube and the dialysis was repeated for 7 days while changing the distilled water every day.
A polymethylmethacrylate emulsion having a solid content of 15.7 wt% was obtained. Prepare this emulsion to 5 wt%,
The dentinal tubules shown in Example 2 were applied to the surface blocked with hydroxyapatite (FIG. 6) and allowed to stand for 30 seconds.
It was dried with compressed air to form a film. It was washed with water for 1 minute, further subjected to ultrasonic waves in water for 35 minutes, and then observed by SEM. The dentinal tubules were open and exhibited the Z surface-like image shown in the figure. The SEM photograph is shown in FIG.

Comparative Example 6 The dentinal tubules were filled with hydroxyapatite in the same manner as in Example 2. After washing with water for 10 seconds, ultrasonic waves were applied for 30 minutes under water. The hydroxyapatite in the dentinal tubules had completely fallen off, and the Z surface-like SEM image of FIG. 5 was exhibited.

Example 4 The NPN cleaning agent was left for 3 days. No separation of the polishing component and the other components was observed, and it was ready to use. Also, 1
No separation was observed even months later.

Comparative Example 7 A cleaning agent obtained by removing hydroxyapatite (Y) from an NPN cleaning agent {X (30 wt%) / propylene glycol (49 wt%) / polyvinylpyrrolidone (21 wt%)} was used as in Example 4. Left for days. The polishing component was precipitated at the bottom and separated from the dispersant. Before use, re-blending with a spatula for 2 minutes was required.

[0069]

The cleaning agent of the present invention has a longest diameter of 100 to 2
Two components of hydroxyapatite, a crushed hydroxyapatite having a diameter of 00 μm and a hydroxyapatite having a maximum diameter of 2 μm or less, are used as polishing components. In the cleaning agent of Example 1 in which propylene glycol and polyvinylpyrrolidone having a specific molecular weight were added as a dispersant, the hydroxyapatite structure, particularly tooth material, was hardly damaged, and stains such as an organic coating film in a short time. Only can be removed. Further, unlike Example 4, there is no separation of the polishing components found in Comparative Example 6, and the storage stability is excellent. Further, since the cleaning agent is not scattered, it is unnecessary to add the cleaning agent during cleaning, which is excellent in cleaning efficiency and economical. In addition, when the cleaning agent is used for cleaning and polishing a multivalent cation-containing adherend such as a hydroxyapatite structure, particularly the surface of a hypersensitivity dentin, not only removal of stains but also dentin as shown in Example 2 Capillaries can be blocked with hydroxyapatite. An emulsion (polymethylmethacrylate emulsion) of an emulsion polymer which does not react with hydroxyapatite as shown in Comparative Example 5 was applied to this cleaned surface to form a film, and then ultrasonic waves were applied to the surface.
After acting for a minute, the membrane falls off and the tubule opens at about the same time as the blank without the membrane of Comparative Example 6. However, when the emulsion of an emulsion polymer having a sulfonic acid group proposed by the applicant is applied and formed into a film, the sulfonic acid group and hydroxyapatite react with each other, so that the hydroxyapatite and the film blocking the thin tube adhere to each other. However, even if ultrasonic waves are applied for 35 minutes, it is possible to form a strong adhesive sealant on which the tubule does not open on the hypersensitive dentin surface. Further, as compared with the case where the present cleaning agent shown in Comparative Example 4 was not used, the capillary sealing property was better, and by combining the present cleaning agent and the emulsion of the emulsion polymer having a sulfonic acid group, the perception It becomes possible to further improve the sealing property of the hypersensitive dentin surface.

[Brief description of drawings]

FIG. 1 is a scanning electron micrograph of a polished surface of human enamel with the cleaning agent of the present invention.

2 is a scanning electron micrograph of the polished surface of FIG. 1 after etching.

FIG. 3 is a scanning electron micrograph of a polished surface with a known cleaning agent for human enamel.

FIG. 4 is a scanning electron micrograph of the polished surface of FIG. 2 after etching.

FIG. 5: Scanning electron micrograph of polished ultrasonically cleaned surface (Z surface) of bovine teeth

FIG. 6 is a scanning electron microscope photograph of the Z surface of a bovine tooth after polishing with the cleaning agent of the present invention.

7 is a scanning electron micrograph after coating the Z surface after polishing of FIG. 6 with a film of an emulsion polymer.

FIG. 8: Scanning electron micrograph after coating the Z surface of bovine tooth with a film of an emulsion polymer having sulfonic acid groups.

9 is a scanning electron micrograph of the polished Z surface of FIG. 6 after being coated with a film of polymethylmethacrylate.

Claims (11)

[Claims] 1. A cleaning agent containing a hydroxyapatite (X) having a maximum diameter of 100 μm to 300 μm and a hydroxyapatite (Y) having a maximum diameter of 2 μm or less as polishing components. 2. The cleaning agent according to claim 1, wherein the hydroxyapatite (X) is amorphous. 3. The cleaning agent according to claim 1, wherein the hydroxyapatite (Y) contains at least one of calcined hydroxyapatite and uncalcined amorphous hydroxyapatite. 4. The cleaning agent contains 5 to 50 parts by weight of hydroxyapatite (X) and 0.1 to 40 parts by weight of hydroxyapatite (Y) per 100 parts by weight of the cleaning agent.
Cleaning agent according to any one of to 3. 5. The cleaning agent according to claim 1, which contains propylene glycol as a moisturizing agent and polyvinylpyrrolidone as a binder. 6. The cleaning agent according to claim 5, wherein polyvinylpyrrolidone has a weight average molecular weight of 500,000 to 4,000,000. 7. 100 parts by weight of a cleaning agent contains 30 to 60 parts by weight of propylene glycol as a moisturizing agent and 10 to 35 parts by weight of polyvinylpyrrolidone having a weight average molecular weight of 500,000 to 4 million as a binder. The cleaning agent according to claim 4. 8. The cleaning agent according to claim 1, which is used for cleaning a tooth surface. 9. A vinyl having (a) a repeating unit derived from (meth) acrylic acid ester and (b) a group --SO ₃ R (wherein R represents a hydrogen atom, an alkali metal atom or an ammonium ion). An emulsion polymer comprising a repeating unit derived from a compound or the above (a),
In addition to the repeating unit of (b), (c) a group —COOR ₄ or a group —OPO (OR ₅ ) ₂ (wherein R ₄ and R ₅ are the same or different, and a hydrogen atom, an alkali metal atom or an ammonium ion is A film formed from an emulsion of an emulsion polymer containing repeating units derived from a vinyl compound having a) is used as a cleaning agent when applied as a sealant for a polyvalent cation-containing adherend. The cleaning agent according to claim 1. 10. The cleaning agent according to claim 9, wherein the sealing material is a tooth sealant. 11. A sealant is a dentin hypersensitivity surface sheet.
The cleaning agent according to claim 9, which is a lumber.