JPH0635485B2 - Room temperature curable polymerizable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a room temperature curing polymerizable composition of a vinyl compound using a sulfoxylate compound and a hemiperic ester of maleic acid as a redox polymerization initiator.

A peroxide having an activation energy for decomposition of 25 to 40 Kcal / mol is used alone as a radical polymerization initiator, but when this is used together with a reducing agent, generation of radicals becomes easy.

A combination of such an oxidizing agent and a reducing agent is called a redox polymerization initiator, which is used for low-temperature polymerization, and is industrially used when emulsion polymerization is performed.

Redox polymerization is also used in the field of dentistry. For example, room temperature curable substances are tooth filling materials (composite resin, etc.), tooth sealants and dental adhesives, caries preventive filling materials, crowns and dentures. Is used for the manufacturing of.

[Conventional technology]

Conventionally, as the room temperature-curable polymerizable composition used as described above, a redox polymerization initiator in which an organic peroxide and a tertiary amine, for example, benzoyl peroxide and dimethylparatoluidine are combined and a polymerizable ethylene-based monomer are used. Compositions and the like composed of saturated substances are known, but materials using these redox polymerization initiators cure rapidly at room temperature, but the cured products are markedly colored (mostly yellow) and sunlight and It had a drawback that only a large change in color tone over time could be obtained in water.

[Problems to be solved by the invention]

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a room temperature curable polymerizable composition which is excellent in coloring and appearance performance and gives a cured product which does not change in color tone with time.

[Means for solving problems]

The room-temperature-curing polymerizable composition of the present invention is a room-temperature-curing polymerizable composition comprising a vinyl monomer and a redox polymerization initiator, wherein the redox polymerization initiator is a combination of a sulfoxylate compound and a maleic acid hemiperester. It is characterized by

The vinyl-based monomer forming the composition of the present invention may be either a monofunctional vinyl compound or a polyfunctional vinyl compound.

Examples of monofunctional vinyl compounds are styrene, acrylonitrile, vinyl acetate, methyl acrylate and methacrylate, ethyl acrylate and methacrylate, butyl acrylate and methacrylate, hydroxyethyl acrylate and methacrylate, methoxyethyl acrylate and methacrylate, glycidyl acrylate and methacrylate, Methacryloxyethyl trimellitic acid and acid anhydrides thereof and the like can be mentioned. Further, examples of polyfunctional vinyl compounds include the following general formula (In the formula, R ₁ represents a hydrogen atom or a methyl group, and p is 1 to
It is an integer of 20. ) Ethylene glycol diacrylate and methacrylate, diethylene glycol diacrylate and methacrylate, triethylene glycol diacrylate and methacrylate, polyethylene glycol diacrylate and methacrylate, 1,4-butanediol diacrylate and methacrylate, 1,3-butanediol Diacrylate and methacrylate, 1,6-hexanediol diacrylate and methacrylate, glycerin diacrylate and methacrylate, and the following general formula (In the formula, R ₂ represents a hydrogen atom or a methyl group, and p is 1 to
It is an integer of 20. ) Bisphenol A diglycidyl acrylate and methacrylate, urethane diacrylate and methacrylate, trimethylolpropane triacrylate and methacrylate,
Examples include pentaerythritol tetraacrylate and methacrylate, bisphenol A diacrylate and methacrylate, and the like. These acrylates and methacrylates may be used alone or in combination of two or more.

The sulphoxylate salt compound preferably used as Redotsukusu polymerization starting agent of the present invention, the general formula MHSO ₂ · CH ₂ O · nH in ₂ O (the following formula, M represents an alkali metal atom or a monovalent transition metal atom , N is a natural number of 0 to 5), or a formaldehyde derivative of a sulfoxylate represented by the general formula MSO ₂ · CH ₂ O · nH ₂ O (where M is an alkaline earth metal atom or a divalent metal). Of the formaldehyde derivative of the sulfoxylate represented by the formula (3), and n is a natural number of 0 to 5, and particularly preferably sodium formaldehyde sulfoxylate, zinc formaldehyde sulfoxylate and the like. .

All maleic acid hemiperesters are applicable,
Particularly preferably, tertiary butyl peroxymaleic acid and the like can be mentioned. These redox polymerization initiators are
It is added in an amount of 10 ^-5 % to 30% by weight, preferably 10 ^-3 % to 20% by weight, particularly preferably 10 ^-1 to 10% by weight, based on the vinyl monomer.

The amount of maleic acid hemiperester compounded is in the range of 1/10 to 10/1 in weight ratio with respect to the sulfoxylate compound. The blending amount of these is suitable for obtaining a composition having high mechanical strength without coloring and color tone change over time of the cured product.

In the composition of the present invention, a filler is optionally added to the above components. Examples of such filler components include Group I, II, III, IV, V periodic metals, transition metals and their oxides, hydroxides, chlorides, sulfates, sulfites, carbonates, phosphates and silicic acids. Examples thereof include salts and mixtures thereof, complex salts, and the like. Among them, silicon dioxide, quartz powder, aluminum oxide, barium sulfate, titanium oxide, talc, glass powder, glass beads, glass fiber,
A glass filler containing barium salt and lead salt, silica gel, colloidal silica, carbon fiber, zirconium oxide, tin oxide and other ceramic powders are preferable.

The above-mentioned filler may be any of an untreated filler, a surface-treated filler such as a silane coupling agent, and an organic composite filler which is compounded with a polymer and pulverized. The blending amount of these fillers can be appropriately changed depending on the purpose of use of the room temperature polymerized cured product, but when used as a filler for dental materials, for example, 1 to 10 ³ wt% relative to the vinyl monomer, Preferably 10-9.5 ×
10 ² % by weight, particularly preferably 20 to 9.0 × 10 ² % by weight, and used as a paste composition. When the storage stability of the compounded paste is required, the composition of the present invention can be divided into two parts, one of which can be compounded with a sulfoxylate compound and the other of which can be compounded with hemiperester maleic acid.

Furthermore, in the composition of the present invention, if necessary, a colorant, a polymerization inhibitor (for example, hydroquinone, methoxybenzophenone, methylphenol, hydroquinone monomethyl ether, etc.), an oxidation stabilizer, an ultraviolet absorber (for example, benzophenone, etc.) ), A pigment (for example, iron oxide, titanium oxide, etc.), a dye, or the like can also be added.

〔Example〕

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to such examples.

Examples 1-2, Comparative examples 1-2 And the following monomer mixture And were rapidly blended at room temperature (20 ° C), and the mixture was then sealed with a Teflon tube (inner diameter: 4 m)
m, height 20 mm) until the upper liquid surface was flush with the upper surface of the Teflon cylinder, and the mixture was allowed to stand for 10 minutes to carry out room temperature polymerization.

Thereafter, the reaction product was removed from the Teflon cylinder, and the appearance and the like of the obtained polymerized cured product were evaluated.

Table 1 shows the kind and amount of the sulfoxylate compound and the above-mentioned evaluation result of the cured appearance.

As is clear from Table 1, the composition according to the present invention is a polymer having excellent room temperature curing performance and no curing coloration as compared with the composition of Comparative Example.

Examples 3-4 and Comparative Examples 3-4 Monomer / Filler mixture (paste) consisting of And are rapidly blended at room temperature (20 ° C.), and then the mixture paste is packed into a Teflon cylinder (inner diameter mm, height 20 mm) whose lower surface is sealed until the upper paste surface matches the upper surface of the Teflon cylinder. Then, room temperature polymerization was carried out by leaving it in that state for 10 minutes. Thereafter, the reaction product was removed from the Teflon cylinder, and the appearance and the like of the obtained polymerized cured product were evaluated.

Table 2 shows the type and amount of the sulfoxylate compound and the above-mentioned evaluation results of the cured appearance.

As is clear from Table 2, even when a filler is added, the composition according to the present invention has a better room temperature curing performance than the composition of the comparative example and is a cured product without coloring. .

Example 5, Comparative Example 5 Changes in color tone after a 1-week exposure test with sunlight and changes in color tone after a 1-week immersion test in 60 ° C. water were measured. The results are shown in Table 3.

As is apparent from Table 3, the composition according to the present invention has extremely high color stability as compared with the composition of Comparative Example 3.

〔The invention's effect〕

Since the room-temperature-curable polymerizable composition according to the present invention uses a redox polymerization initiator composed of a sulfoxylate compound and a hemiperester maleate, it is composed of a conventional organic peroxide and a tertiary amine. As compared with the polymerization initiator, it is possible to obtain a cured product having excellent curing performance at room temperature and excellent appearance performance without coloring.

Claims (6)

[Claims] 1. A room temperature curing polymerizable composition comprising a vinyl monomer and a redox polymerization initiator, wherein the redox polymerization initiator is a combination of a sulfoxylate compound and a maleic acid hemiperester. Curable polymerizable composition. 2. The room temperature curable polymerizable composition according to claim 1, further comprising a filler in addition to the vinyl monomer and the redox polymerization initiator. 3. sulfoxylate salt compound has the general formula MHSO ₂ · CH ₂ O · nH in ₂ O (wherein, M represents an alkali metal atom or a monovalent transition metal atom, n represents a natural number of 0 to 5 Formaldehyde derivative of sulfoxylate or a general formula MSO ₂ · CH ₂ O · nH ₂ O (wherein M represents an alkaline earth metal atom or a divalent transition metal atom, and n is 0). The room temperature curable polymerizable composition according to claim 1 or 2, which is a formaldehyde derivative of a sulfoxylate represented by the formula (1) to (5). 4. A maleic acid hemiperester is represented by the general formula: (In the formula, R represents a saturated tertiary alkyl group.) The room temperature curable polymerizable composition according to claim 1, which is represented by the formula. 5. A sulfoxylate compound as claimed in claim 1, which is sodium formaldehyde sulfoxylate or zinc formaldehyde sulfoxylate.
The room temperature curable polymerizable composition according to item 2 or 3. 6. A maleic acid hemiperester is tertiary butyl peroxymaleic acid.
Item 2. The room temperature curable polymerizable composition according to item 2 or 4.