JPS58201628A - Hardening method of hardenable resin - Google Patents

Abstract

PURPOSE:To shield a preform from contact with the outside air at the time of hardening and cause the hardening to proceed sufficiently to a surface layer, by a method wherein a masking agent comprising PVA and water as main constituents is applied to a preform of a hardenable resin, and then the preform is hardened. CONSTITUTION:An anaerobic catalyst such as benzoyl peroxide and a photo- sensitizer such as benzoin are added to a hardenable resin such as a (meth)acrylic acid ester resin in amounts of, for example, 0.1-3wt% and 0.05-10wt%, respectively, and the mixture is preformed. A masking agent comprising preferably 15-40% of PVA (preferably having an average molecular weight of 20,000), water and, if necessary, up to 15% of a PVA plasticizer such as a polyalkylene alcohol is applied to the preform by a spraying method or the like. Then, the preform is hardened, and the coated film is stripped. USE:Preferable for dental materials.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of curing a curable resin. More specifically, the present invention relates to a method of curing a curable resin, which comprises curing a preform of the curable resin.

When heat-curing a thermosetting resin using an anaerobic curing catalyst, it is common to first make a preform and then heat-cure it. The surface is insufficiently hardened, resulting in defects such as insufficient surface hardness and poor appearance. especially,
In the field of dental materials using (meth)acrylic acid ester resins, strict hardness, abrasion resistance, dimensional accuracy, etc. are required of molded and cured products, and there is a strong desire to eliminate these drawbacks. Further, a similar situation can be seen in the case of room temperature curable resins and photocurable resins.

In order to improve these shortcomings, various fast-curing resins and resin compositions, fast-curing catalysts, curing accelerators, etc. have been proposed, but sufficient results have not yet been obtained, and sometimes molded cured products In some cases, surface treatment such as scraping off insufficiently hardened portions of the surface layer was necessary. Another commonly known method is to cover part or all of the preform with a ready-made film, cut off contact with the outside air, and then heat cure it. It is difficult to apply this method to materials with curved surfaces or curved surfaces, and in particular, it has been impossible to apply it to the field of dental materials.

The present inventors have discovered that a simple method of applying a specific masking agent to a curable resin preform and curing the preform eliminates all the drawbacks caused by the various curing methods proposed in the past. found that it is possible to overcome this.

Therefore, the present invention relates to a method for curing a curable resin, and the curing of the curable resin is performed by coating a preform of the curable resin with gelvinyl alcohol and water, or a masking agent containing them as main components. This is done by curing the preform.

According to the curing method of the present invention, the film formed by the masking agent blocks contact between the preform and the outside air during curing, so that the curing of the curable resin by the anaerobic curing catalyst or the like does not affect the molded and cured product. The coating progresses sufficiently to the surface layer, leaving no uncured or semi-cured parts.

The preformed product of a curable resin means an uncured or semi-cured molded product produced by a conventional method. The molded product in this case is, for example, a metal coated with a curable resin solution, a curable resin putty or cake-like material built up on a metal, or a curable resin putty-like material applied to a mold. It refers to molded products in a broad sense, including those filled with objects or cake-like materials. Note that during this preforming, there is no problem even if the material is heated in detail.

As the curable resin to be preformed, one that is cured by heating, room temperature, or photocuring is used.

Examples of resins that harden by heating or at room temperature include vinyl compound resins that polymerize in the presence of an anaerobic curing catalyst, such as acrylic ester resins, methacrylic ester resins, and unsaturated polyester resins. Examples of traditional materials include methacrylate ester teeth with trade names such as Isojit O&B (manufactured by Hakusui Trading Co., Ltd.), Thermoresin (manuji dental industry products), and Vita ni & B (products sold by Vita). Examples include hard resins for crowns, and methacrylate-based composite resins with trade names such as Adabuchitsuku (sold by Sankin Kogyo) and Superlux (sold by Shofu Tooth).

These curable resins mainly refer to mixtures of two components: a catalyst (for example, methacrylic acid ester resin + catalyst) and a base (methacrylic acid ester), each generally in the form of a powder or paste. As the anaerobic catalyst as a catalyst component, one whose main component is an organic peroxide or an azo compound is used.

Examples of organic peroxides include pencey peroxide/l',
tertiary phtylbarbenzony), tertiary butyl hydroperoxide, ditertiary butyl peroxide, cumene hydroperoxide, dibutyl peroxydicarbonate, tertiary butyl hydroperoxide
Examples of the azo compound include azobisisobutyronitrile, 1.1'-azobiscyclohexyl-1-carboethryl, 2.2'-azobis(2 ,4-
Examples include dimethyl pareda nitrile).

In the case of curing at room temperature, a mixture of these organic peroxides with alune, sulfinic acid, etc. added thereto is used as a catalyst. For example, p-tolylgetanolamine, NatsuHP-dihydotanoxyethyl-3,5-xylidine, N-hydroxyethylaniline, N-methylaniline, M,M'-dimethylaniline, ethanolamine, etc. is used, and examples of sulfine include p-)luenesulfine, benzenesulfine mt
or their alkali metal salts, alkaline earth metal salts, etc.

These curing catalysts generally have a ratio of about 0.1 to curable resin.
It is used in a 3 to 3 weight range and is mixed into the curable resin before preforming.

In addition, the photocurable resin is a vinyl compound resin that is cured by irradiation with light in the presence of a photosensitizer, such as acrylic ester resin, Metac IJ /I/ 乍x
Examples include X-chill resin and unsaturated polyester resin. Examples of dental materials include Estilux (sold by Kurtour), Ubiorfil (sold by Espe), Super Lux Delight (sold by Shofu Tooth), and Photofil (sold by Jibenson and Jibenson). Methacrylic acid ester resins under any trade name may be mentioned.@Photosensitizers added to these photocurable resins include:
Benzoin, benzoin methyl ether, benzyl, diacetyl, benzophenone, acetophenone, Michler's ketone, etc., or those obtained by adding a second component to these to improve sensitization are used. These photosensitizers are generally used in a proportion of about 0.05 to 10% by weight based on the photocurable resin.

The masking agent used in the present invention is usually also called a masking agent, and contains polyvinyl alcohol and water or both as main components. As polyvinyl alcohol, one having an average molecular weight of about 20,000 is preferably used, but it is not limited thereto. In addition to these two components, the masking agent may contain a component that plasticizes polyvinyl alcohol, such as a mono- or polyalkylene glycol such as ethylene glycol, tetrapyrene glycol, polyethylene glycol, or polyalkylene glycol. is preferable, and pigments and dyes such as titanium oxide and pengara can also be added.

The amount of vinyl alcohol in the masking agent is approximately 15 to 4
It is desirable to adjust the concentration to about 0 weight≦, and it is desirable to include the plasticizer such as mono- or polyalkylene glycol in the masking agent at a concentration of 15 weight class or less.

Application of a masking agent to a preformed product of curable resin is generally performed by a method using an instrument such as a spray or a brush, or by a dipping method. The preform coated with the masking agent is cured by conventional methods such as heat curing, room temperature curing, or light irradiation curing. At this time, water, which is a masking agent component, evaporates, and a cured film containing polyvinyl alcohol or polyvinyl alcohol as its main component is formed there. In some cases, before the preform is cured, the masking agent may be precured by blowing air or the like to form a film, and then the preform may be cured. After curing is completed, by peeling off the masking agent coating using a bottle set, spatula, etc., a molded product that is sufficiently cured up to the surface layer can be obtained in a shorter curing time.

Next, the present invention will be explained with reference to examples.

Example 1 Polyvinyl alcohol (average molecular weight 20,000) 20 parts (weight, same below), polyethylene glycol (average molecular weight 4
00) Stir a mixture of 1 g part and 40 parts water.9
It was heated to 0 C to dissolve the polyvinyl alcohol.

After cooling this solution to room temperature, 0.05 part of titanium oxide was added and thoroughly kneaded in a mortar, and 10 parts of ethanol was further added to prepare a cloudy and viscous masking agent.

This masking agent was used in the following manner when molding and curing a hard resin for dental crowns.

Hard resin molding material (Isoshira sold by Hakusui Trade) 0&E
) to form a paste by mixing the compounding materials in the proportions specified in the prescription. Vertical lO in the center
A formwork of a 5-inch thick L-tetrafluoroethylene plate with a horizontal 10-hole cut out was stacked on a glass plate in advance, and the paste was filled in the letter hole with stainless steel. The surface was made flat using a manufactured spatula.

Apply approximately 0 of the masking agent to the surface of the paste filled in the hole.
．． After applying it with a brush to a thickness of 5cm, the entire formwork is heated to 4cm in a polymerization vessel (
(Shofu porcelain tooth products) and heated at 120° C. for 20 minutes at 4 to 40°C. After 20 minutes, the mold was removed from the mini polymerization vessel, cooled to room temperature, and then the masking agent coating was peeled off with tweezers. At this time, the surface of the cured resin layer was not peeled off, and even when the surface was scraped with a spatula, there was no uncured or semi-cured portion that could be scraped off. The thickness of the formed hard resin layer for the dental crown is the same as the thickness of the form board.
+m.

Comparative Example 1 In Example 1, the hard resin molding material was cured without applying a masking agent.

After cooling to room temperature, the surface of the cured resin layer was scraped with a spatula, and 0.72j9 of uncured or semi-cured material was scraped off.

From the comparison between Example 1 and Comparative Example 1 above, it can be seen that approximately 14 square meters of hard resin molding material is lost, and this not only requires more effort to scrape off uncured or semi-cured materials. , it also requires the complexity of predicting the amount of loss and building up.

Example 2 In Example 1, another hard resin molding material (Thermoresin sold by Menshi Dental Industry) was used. ◇After the masking agent was removed with a bottle set, the surface of the cured resin layer was scraped with a spatula. There were no uncured or semi-cured parts that could be scraped off.

Comparative Example 2 In Example 2, the hard resin molding material was cured without applying a masking agent. After cooling to room temperature, the surface of the cured resin layer was scraped with a spatula. The cured or semi-cured material was scraped off.

Example 3 In the shoulder of the masking agent of Example 1, the same amount of propylene glycol was used instead of 1-lyethylene glycol, and titanium oxide was not used.

Using the transparent viscous masking agent thus prepared, a hard resin molding material was cured in the same manner as in Example 1. After the masking agent was removed with a bottle set, even when the surface of the cured resin layer was scraped with a spatula, there was no uncured or semi-cured portion that could be scraped off.

Example 4 Molding and curing of the congodite resin for cavity filling using the masking agent of Example 1 was carried out as follows.

A hole with a diameter of 4 m is cut out of a 4-thick polytetrafluoroethylene plate, and with a flat glass plate placed on one side, the hole in the mold is filled with composite resin molding material (Estilax, a product sold by Kultur). flattened with a stainless steel spatula.

Apply approximately 0.51% masking agent on the molding material layer filled in the hole.
After applying with a brush to a thickness of 111, using an ultraviolet irradiation device (Kurtur product Duralux TIV300) I,
Light was irradiated for 0 seconds. At this time, the distance between the irradiation port and the molding material layer was set to about 2 m. Thereafter, air was blown onto the surface of the masking agent for about 2 minutes to dry it, and the masking agent film was removed with a spatula. Even when the surface of the cured resin layer was scraped with a spatula, there was no uncured or semi-cured portion that could be scraped off. In addition, as a result of examining the depth of curing by scraping the surface of the cured resin opposite to the light irradiation surface with a spatula, it was found that 2.5-thickness of the thickness of the resin had been rapidly cured.

Comparative Example 3 In Example 4, the composite resin molding material was cured without applying a masking agent.

After light irradiation, when the surface of the cured resin layer was scraped with a spatula, 0.5 to 0.5 of uncured or semi-cured material was scraped off.

Further, the curing depth of the cured resin was 2.2■.

Example 5 Catalyst paste and base paste of a composite resin molding material (Estilux, sold by Kultur) were kneaded in approximately equal amounts, filled in the holes of the formwork of Example 1, and then added to the molding material of Example 1. Masking agent No. 1 was applied to a thickness of about 0.5101 mm using a spatula. After standing for 1 hour, the masking agent coating was peeled off and the Brinell hardness of the cured resin layer was measured, and a value of 30 was obtained. Further, even when the surface of this layer was scraped with a spatula, there was no uncured or semi-cured portion that could be scraped off.

Comparative Example 4 In Example 5, the composite molding material was cured without applying a masking agent.

After standing for 1 hour, the surface of the cured resin layer was scraped with a spatula, and the uncured or semi-cured portions of 211I9 were scraped off. The cured resin layer after these portions were scraped off had a Purinelle hardness of 26.

Example 6 The unsaturated polyester was coated and cured using the masking agent of Example 1 as follows.

10 parts of an unsaturated polyester coating material (Sugoratsuku 2004, sold by Ohken Shoji) and 15 parts of titanium oxide were roll-kneaded, 0.01 part of benzoyl peroxide was added thereto, and the mixture was further kneaded to prepare a white paint.

Approximately 0.5 g of this white paint is applied onto an iron plate approximately 0.5 g thick.
Apply the masking agent to a thickness of approximately 0.2 m.
It was applied to a thickness of . This was placed in a dryer and heated at 80° C. for 1 hour to harden it. After cooling to room temperature, the masking agent coating was peeled off with tweezers, and the pencil hardness of the cured coating layer was examined and found to be 3H.

Comparative Example 5 In Example 6, the unsaturated polyester coating material was cured without applying a masking agent. The pencil hardness of the cured coating layer was 2H.

Representative Patent Attorney Yoshi 1) Toshio Proceeding Amendment (Spontaneous) July 9, 1980 Director General of the Patent Office Kazuo Wakasugi 1. Indication of the case 1982 Patent JIi No. 85580 2. Name hardening of the invention Relationship with the Case of Person Who Amends Method of Curing Resin 1 Patent Applicant Name (588) Mitsui Petrochemical Industries, Ltd. (and 1 other person) 4, Agent Address 1-2-7 Shiba Daimon, Minato-ku, Tokyo Ato building 50
Section 6 of the detailed description of the invention in Specification No. 1, Contents of amendment

Claims (1)

[Claims] 1. A curable resin characterized by applying polyvinyl alcohol, water, or a masking agent containing these as main components to a curable resin preform, and then curing the preform. curing method. 2. The curing method according to claim 1, wherein a masking agent containing a plasticizer for polyvinyl alcohol is used. 3. The curing method according to claim 2, wherein the plasticizer for polyvinyl alcohol is mono-Otahagi realkylene glycol.