JPH0116250B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for ring-opening polymerization of bicyclo compounds. For details, see the formula,

This is a method of ring-opening polymerization of a bicyclo compound having a bicyclo ring represented by the formula in its molecule using an organic acid with an acid dissociation constant (PKa) of 1.5 or more and water as a catalyst. It has been known that various types of bicyclo compounds can be used as stabilizers for vinyl chloride resins, herbicides, and the like. In addition, when ring-opening a bicyclo compound using these known methods, generally
Catalysts such as BF ₃ ·OEt ₂ , PF ₅ , CF ₃ SO ₃ H are used. Although these catalysts are certainly effective for ring-opening of bicyclo compounds, they may not be usable depending on the use of the bicyclo compound. For example, the present inventors have attempted to use bicyclo compounds as dental materials. However, conventionally known catalysts could not be used in the oral cavity and could not be practically used as dental materials. Therefore, an object of the present invention is to develop a ring-opening catalyst for bicyclo compounds that can be used satisfactorily even in the oral cavity. In order to achieve the above object, the present inventors have been conducting intensive research and development of catalysts. As a result, the inventors discovered that a catalyst consisting of a specific organic acid and water is an excellent catalyst for the ring-opening polymerization reaction of bicyclo compounds, and completed the present invention. The present invention is based on the formula

Ring-opening polymerization of a bicyclo compound, which is characterized by ring-opening polymerization of a bicyclo compound having a bicyclo ring represented by the formula in its molecule using an organic acid with an acid dissociation constant (PKa) of 1.5 or more and water as a catalyst. It's a method. The bicyclo compounds that are the object of the present invention are bicyclo rings, that is,

There are no particular limitations as long as the compound has [Formula] in its molecule.
In general, the formula The most typical example is a bicyclo compound represented by the formula (wherein R ₁ and R ₂ represent the same or different hydrogens or monovalent organic groups). The above-mentioned monovalent organic group is not particularly limited, and any group may be used. Specific examples of generally suitably used monovalent organic groups include CH ₃ −, C ₂ H ₅ −, n-C ₃ H ₇ −, iso-
C ₃ H ₇ −, n−C ₄ H ₉ −, iso−C ₅ H ₁₁ −, C ₁₀ H ₂₁ −
Saturated hydrocarbon residues such as; _H2C =CH- group, _CH3-
CH=CH- group,

[Formula] Unsaturated hydrocarbon residue having groups, etc.; NH ₂ −, CH ₃ NH−,

Organic groups containing amino groups such as [Formula]; CH ₃ CONH−, CH ₃ NHCONH−,

Organic group containing an amide group such as [Formula]; CH ₃ NHCOOCH ₂ −, CH ₃ CH ₂ NHCOOCH ₂
-Organic group containing urethane group such as _CH2 =CHCOO
−, CH ₂ =C(CH ₃ )COO−, CH ₂ =
CHCOOCH ₂ −, CH ₂ =C(CH ₃ )COOCH ₂ −,
_CH2 =C( _CH3 ) _COO ( _CH2CH2O )-m,

Acrylic acid represented by the formula (where m is an integer from 1 to 500), etc.
Residues such as methacrylic acid; organic groups in which some or all of the hydrogen atoms are replaced with halogen atoms, hydroxyl, etc.; The most important feature of the present invention lies in the catalyst used in ring-opening polymerization of the bicyclo compound. That is, the catalyst of the present invention is composed of an organic acid having an acid dissociation constant (PKa) of 1.5 or more and water. For example, organic acids with an acid dissociation constant (PKa) of 1.5 or more can be found in the Basics of Chemistry Handbook. Organic acids such as those described on pages 1054 to 1058 (September 25, 1960, published by Maruzen Co., Ltd.) can be used without particular limitation. Specifically, the organic acids that are particularly preferably used include acetic acid, methacrylic acid, acrylic acid, P-toluenesulfinic acid, vinylphosphonic acid, P-toluenesulfonic acid, benzoic acid, cyclohexanecarboxylic acid, These are organic carboxylic acids, phosphoric acids, and sulfonic acid compounds such as glycolic acid, propionic acid, tartaric acid, citric acid, adipic acid, and succinic acid. The catalyst in the present invention requires the presence of the above-mentioned specific organic acid compound, but if only the above-mentioned organic acid compound is present, the above-mentioned bicyclo compound cannot cause the ring-opening reaction. In the present invention, it is necessary that water be present in the reaction system in addition to the above-mentioned organic acid compound. The mechanism of how the presence of water in the catalyst system of the present invention acts on the ring opening of the bicyclo compound is not clear. The present inventors estimate that the presence of water promotes the dissociation of the organic acid, so that the ring-opening reaction of the bicyclo compound occurs. Although the catalyst of the present invention requires the presence of water as described above, the presence of water is not necessarily suitable for treating the product after the ring-opening polymerization reaction of the bicyclo compound. Therefore, it is preferable that the amount of water present in the reaction system be as small as possible. Therefore, it is preferable to determine the necessary amounts of organic acid and water in advance depending on the type of bicyclo compound and reaction conditions. In general, it is preferable to select the organic acid and water in a range of 0.01 to 20% by weight, preferably 0.1 to 10% by weight, based on the bicyclo compound. The method for ring-opening polymerization of a bicyclo compound in the present invention is not particularly limited, and any known method may be employed. Generally, if the bicyclo compound is in liquid form,
If it is in solid form, it may be dissolved in a suitable solvent such as methyl methacrylate or methyl acrylate, and then the organic acid and water may be added and mixed. The reaction may be carried out in any manner, but generally a method of carrying out the reaction in a mold or by casting between plates is often suitably employed.
Furthermore, the conditions for the ring-opening polymerization reaction of the bicyclo compound are not particularly limited and may be selected and adopted as appropriate, but it is usually carried out at a temperature of 0°C to 200°C, preferably 30°C to 130°C, for several minutes to several hours. All you have to do is react. For the catalyst of the present invention, an organic acid having an acid dissociation constant of 1.5 or more is preferably used, but especially when carrying out the ring-opening polymerization reaction of a bicyclo compound in the oral cavity as a dental material, the acid dissociation constant is 2.0 or more. Preferably 3.0
This can be suitably carried out by using a value of 4.0 or more, more preferably 4.0 or more. Therefore, the contribution of the present invention is extremely large as it has made it possible to use bicyclo compounds as new materials, which could not be used for dental purposes or the like because there was no catalyst that could be used in the oral cavity. In carrying out the present invention, the polymer obtained in the present invention may be mixed with fillers, adhesives, etc. conventionally known in the dental industry, and in the reaction of the present invention, the polymers obtained in the present invention may be mixed with fillers, adhesives, etc. that are known to be used in dentistry. A mixture of polymerizable monomers can be used. Examples of particularly suitable polymerizable monomers for mixing include methyl methacrylate, methyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, ethylene glycol methacrylate, di- or tri- or tetra-ethylene glycol diacrylate, and bisphenol A diacrylate. ,2,2′−
Bis(methacryloxyethoxyphenyl)propane, 2,2'-bis(γ-methacryloxy-β
-hydroxypropoxyphenyl)propane,
N,N-dimethylaminoethyl methacrylate,
These include glycidyl methacrylate, styrene, and vinyl acetate. It is also effective to add polymeric compounds such as polymethyl methacrylate, polyethyl methacrylate, polystyrene, unsaturated polyester resin, and epoxy acrylate resin to adjust the viscosity and curing speed during the reaction. EXAMPLES In order to explain the present invention more specifically, the present invention will be described below with reference to Examples, but the present invention is not limited to these Examples. Examples 1 to 7, Comparative Examples 1 to 3 3 g of 1,4-diethyl-2,6,7-trioxabicyclo[2,2,2]octane was introduced into a 5 ml sealed ampoule. Immediately after adding the organic acids and water shown in Table 1 below, the mixture was frozen in dry ice. Thereafter, the tube was degassed for about 1 minute and sealed.
The reaction was carried out at 37°C for 20 hours after dissolving the mixture in the ampoule. The ring opening rate of bicyclo ring, which is a guideline for catalytic ability, is determined by the ¹ H-NMR spectrum of 1,4-diethyl-2,6,7-trioxabicyclo[2,2,2]octane before reaction and the mixture after reaction. Calculated from. Let the absorption intensity based on the six methylene protons of the bicyclo ring before and after the reaction be a, and the absorption intensity based on the other protons b and b', respectively, then the ring opening rate x
(%) can be expressed by the following formula. x (%) = ab′−a′b/a(a′+b′)×10
0 The results obtained from the above measurements are shown in Table 1 below. Also, for comparison, 1,4-diethyl-2,6,
The same measurements as above were carried out when BF ₃ CEt ₂ , known as a bicyclo ring-opening catalyst, was added to 7-trioxabicyclo[2,2,2]octane and when only an organic acid was added, and the results are shown below. It is also listed in Table 1.

【table】

[Table] Examples 8 to 10, Comparative Example 5 1,4-diethyl-2, used in Examples 1 to 7
6,7-trioxabicyclo[2,2,2]octane to 1-ethyl-4-methacryloxymethyl-
2,6,7-trioxabicyclo[2,2,2]
Table 2 shows the results of experiments conducted in the same manner as in Examples 1 to 7, except that octane was used and the reaction temperature was 70°C. In addition, it is known as a bicyclo ring-opening catalyst.
An experiment similar to the above was conducted in the case where BF ₃ .OEt ₂ was added, and the results are also listed in Table 2.

【table】

Claims (1)

[Scope of Claims] 1. Ring-opening polymerization of a bicyclo compound having a bicyclo ring represented by formula [formula] in the molecule using an organic acid with an acid dissociation constant (PKa) of 1.5 or more and water as a catalyst. Characteristic method for ring-opening polymerization of bicyclo compounds. 2. The ring-opening polymerization method according to claim 1, wherein the organic acid and water are each used in an amount of 0.01 to 20% by weight based on the bicyclo compound.