JP2557564B2 - Oxygen blocker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention provides a method for coating the surface of a polymerization-curable acrylic resin, which is susceptible to polymerization inhibition by oxygen in the air, and shielding the resin surface from oxygen. It relates to an oxygen barrier agent for promoting its curing. What is Polymerization-curable acrylic resin? Dental filling / restoring composite resin, Dental crown prosthesis resin, Dental resin adhesive (cement), Dental pit and fissure sealant, and basically with them It refers to composite resin etc. used in the field of arts and crafts that have the same structure.

[Prior Art] In recent years, in the field of dental treatment, the use of polymerization-curing acrylic resin, which has excellent aesthetics and operability, has been generalized for the restoration of tooth defects, and not only direct filling of caries but also large defects. Polymerization-curable acrylic resins have been tried to be used for restorations for dental prostheses such as inlays, onlays and crowns used for restoration, and also for resin adhesives (cement).

Dental polymerization-curable acrylic resin is a composition consisting of an acrylic monomer, a radical polymerization initiator and a filler, and after shaping the composition into a desired shape, the acrylic monomer is polymerized and cured to cause caries. Are treated and the restorations for treatment are prepared.

By the way, when trying to radically polymerize an acrylic monomer in air, the polymerization reaction is inhibited by oxygen,
There is a problem that an unpolymerized layer is formed on the surface of the restoration. For example, a pre-polymerized dental composite resin has a monomer-rich layer on its surface that makes the pre-polymerized resin surface look very smooth. When it is wiped with or washed with a solvent, the unpolymerized layer on the surface is removed and the surface becomes rough.

Therefore, many proposals have been made to eliminate the inhibition of polymerization due to oxygen. For example, JP-A-60-100505 discloses that an aqueous mixture of a water-soluble organic substance (polyvinylpyrrolidone, polyvinyl alcohol) containing a surfactant is applied to the surface of a photopolymerizable resin, and oxygen is obtained by irradiating light through the aqueous mixture. Blocking improvement method, JP-A-58-201628 discloses a method for curing a curable resin in which a curable resin is cured after applying a masking agent composed of polyvinyl alcohol or polyethylene glycol and water, and JP-A-59-36604 discloses Masking agent for forming curable resin containing polyvinyl alcohol, water and organic peroxide as main components, and JP-B-63-
No. 37082 proposes a surface-hardening agent, which is formed by mixing polyethylene glycol having an average molecular weight of 150 to 420 and polyethylene glycol having an average molecular weight of 1800 to 20000 in a paste form. The sex was not enough. It is considered that the reason is that a very small amount of unpolymerized monomer remains on the surface of the cured product. Further, JP-A-60-31858 proposes a volatile solvent solution containing at least one surface hardening agent selected from the group of peroxides, amines, and sulfinic acids. Since the organic solvent dissolves and removes the monomer from the surface of the composite before polymerization, the filler is projected on the surface of the composite after curing to give a white appearance, and the effect is insufficient.

[Problems to be Solved by the Present Invention] An object of the present invention is to develop a high-grade oxygen barrier agent capable of leaving gloss on the composite surface after polymerization.

[Means for Solving the Problems] The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as an oxygen blocking agent, the liquid is a liquid having a small amount of dissolved oxygen or a slow oxygen diffusion rate. We searched for a liquid that has low solubility and has no phenomenon of removing or migrating monomers, has a high solubility in water, and can be easily removed by washing with water after use. As a result, they have found that a compound having a large number of hydroxyl groups in one molecule is effective, and that glycerin or an oligomer of glycerin is effective as such, and the present invention was reached. That is, it is a liquid oxygen blocker for a polymerization-curing acrylic resin characterized by containing (a) glycerin or a glycerin oligomer and (b) a surfactant. When the oxygen blocker is applied to the surface of the composite before polymerization and the composite is polymerized, the composite can be polymerized and cured while maintaining the gloss of the surface.

Examples of the glycerin or glycerin oligomer that can be used in the present invention include glycerin, diglycerin,
Examples thereof include triglycerin.

Further, when such a compound is applied to the surface of the composite, the surface of the composite is repelled and the surface cannot be satisfactorily coated. However, the addition of a surfactant can alleviate this problem. Examples of the surfactant include alkylbenzene sulfonate, α-olefin sulfonate, alkane sulfonate, quaternary ammonium salt containing a long chain alkyl group, fatty acid mono, diethanolamide, fatty acid (poly).
Ethylene glycol ester or ether, monofatty acid glycerin ester, fatty acid sorbitan ester, fatty acid sorbitan ester polyoxyethylene, alkylphenyl polyoxyethylene ether, N-alkyl betaine type anion type, cation type, nonionic type such as sulfobetaine type , Amphoteric type Conventionally known types can be used. The amount of surfactant added is 0.05 based on the total weight of the composition.
-5%, more preferably 0.1-3%.

Further, a reducing agent may be added to the oxygen barrier agent of the present invention for the purpose of further reducing the dissolved oxygen concentration. Such a material is effective when the oxygen barrier agent is applied very thinly. As the reducing agent, those having a polymerization inhibiting action such as phenol are not preferable, and those having no polymerization inhibiting action such as sulfite and hyposulfite are preferable, and sodium benzenesulfinate, sodium toluenesulfinate, sodium sulfite, etc. preferable. Regarding the amount of the reducing agent added, it cannot be generally stated depending on the container (the size of oxygen permeability) to which the oxygen barrier agent of the present invention is supplied, the storage period and the usage condition (whether or not the lid is left open), but there is a margin. Obviously, the saturated dissolution amount of the reducing agent in glycerin or the like or about 10 times thereof may be used. In this case, the excess reducing agent precipitates at the bottom of the oxygen barrier agent container, but as the reducing agent in the liquid is consumed, the solid reducing agent dissolves and the reducing agent in the liquid is automatically replenished. (Always maintain saturated solubility).

Further, the viscosity may be adjusted to improve usability, and a low viscosity can be obtained by mixing a small amount of water, or a high viscosity product can be prepared by blending glycerin and diglycerin or triglycerin. The oxygen barrier agent of the present invention having a viscosity of 500 to 5000 centipoise is easy to use.

In addition, colorants, fragrances, preservatives, stabilizers and the like can be added to the oxygen blocker, if necessary.

This oxygen barrier can be used by directly applying it to the surface of an unpolymerized polymerization-curing acrylic resin, but the shape of the resin may be changed by the pressure of the brush and the weight of the oxygen barrier. In such a case, the resin may be partially polymerized and cured once, and then an oxygen barrier agent may be applied to the surface for further polymerization.

[Effects of the Invention] When the oxygen blocking agent of the present invention is applied to the surface of a polymerizable polymerization-curable acrylic resin using an acrylic monomer and the resin is polymerized, generation of an unpolymerized layer is prevented and a smooth surface is obtained. You can

[Example] (Evaluation method) A photopolymerizable dental composite resin (Kuraray Co., Ltd., Clearfill Photoposteria) was spread on a glass slide for a microscope as flat as possible and held in a dark place for 1 minute. After confirming that the composite surface has gloss, drop a few drops of various oxygen blockers with a dropper and apply visible light for 1 minute with a dental irradiator (Morita Corporation, α-light). Irradiation was applied to cure the composite resin. After that, the surface of the composite resin was washed with running water to remove the oxygen blocker, and further washed with acetone to wash off the unpolymerized monomer, and the presence or absence of gloss on the portion coated with various oxygen blockers was judged. In this method, the filler is exposed at the surface where polymerization is inhibited, and the surface has a rough white appearance and does not show gloss. In addition, the surface-promoted portion has a smooth appearance, and the gloss is measured.
Gloss is measured using Nippon Denshoku's gloss meter type VG-107, and the reflected light intensity of 60 degrees when the incident angle is 60 degrees is the reflected light intensity with respect to the reflected light intensity (100%) by the mirror. Is shown in%. As a measure of the gloss by this method, when the gloss of the pressure-bonded surface (almost perfect flat surface) of the glass of the composite, which can be said to be the limit of the smoothness of the composite, was measured, it showed a reflectance of 62.7%. The gloss of the glossy marble was 64%. Further, the surface gloss of the composite polymerized in air was about 1%.

Examples 1 to 3 The oxygen barrier agents shown in Table 1 were applied to the above-mentioned composite surface, the composite was polymerized, and the surface gloss of the portion where the oxygen barrier agent was applied was measured. The results are shown in Table 1.

In this test method, the surface of the composite cannot be evaluated as a flat flat surface without unevenness, so data as much as the gloss of the above-mentioned glass pressure contact surface (perfect flat surface) is not obtained, but there is considerable gloss visually. Both in terms of gloss value and macroscopic observation, a significant effect was clearly shown in comparison with Comparative Examples described later.

Comparative Examples 1 to 11 For comparison, various oxygen blocking agents shown in Table 2 were used to polymerize the composite, and the surface gloss of the portion where the oxygen blocking agent was applied was measured. The results are shown in Table 2.

Comparative Example 12 A surface curing agent prepared by dissolving 1 part by weight of benzoyl peroxide in 99 parts by weight of ethanol was prepared and evaluated in the same manner as in Comparative Example 1. The surface of the composite after curing was rough due to the loss of the monomer. Shows the appearance,
The gloss was also 2%.

Comparative Example 13 A liquid consisting of 5 parts by weight of sodium benzenesulfinate and 95 parts by weight of ethanol was prepared as a surface curing agent, and the same evaluation as in Comparative Example 1 was performed. It was rough and had a gloss of 3%.

Example 4 A solution consisting of 100 parts by weight of glycerin and 1 part by weight of polyoxyethylene sorbitan monolaurate, to which 2 parts by weight of sodium sulfite was added (sodium sulfite cannot be completely dissolved and sinks to the bottom of the container) is oxygen-blocked. Created as an agent. This product, when applied to the composite resin described in Example 1, showed good applicability without being repelled by the surface. When the gloss of the surface of the composite resin polymerized by applying this was measured by the same method, it showed an excellent gloss of 39%.

Example 5 An oxygen blocker was prepared by adding 2 parts by weight of sodium benzenesulfinate to a solution containing 100 parts by weight of glycerin and 0.5 part by weight of polyoxyethylene glycol-p-nonylphenyl ether. Next, the composite described in Example 1 was stretched into a strip of 5 × 25 cm, a letter was written on it with an oxygen barrier agent with a brush, and the composite was polymerized by exposing it to direct sunlight for 5 minutes. Then, after the cured product was washed with water and acetone, it was dipped in a 0.1% basic fuchsin aqueous solution (red dye) for 5 seconds, and the part of the letters coated with the oxygen barrier showed a glossy surface. It was not dyed red, but the rest of the surface was rough and dyed red.

Claims (1)

(57) [Claims] 1. A liquid oxygen barrier agent for a polymerization-curing acrylic resin, which comprises (a) glycerin or a glycerin oligomer and (b) a surfactant.