JP2001139521A - Method for producing polymerizable polyfunctional methacryl oligomer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a polymerizable polyfunctional methacryl oligomer soluble in a general purpose solvent, not forming an insoluble gelatinous substance even in the case of using a polyfunctional acrylate containing >2 acryloyloxy groups in one molecule as a starting substance. SOLUTION: (a) A polyfunctional acrylic ester in an amount of 1 mol is reacted with (b) P mols of a monofunctional acrylic ester and (c) Q mols of formaldehyde or its equivalent in a 1-6C alcohol solvent in the presence of a basic catalyst. P and Q are each a number for satisfying the following formulas. 0.8n<=P<=2n and 0.8(n+P)<=Q<=1.5(n+P) ((n) is the number of acryloyloxy groups in the polyfunctional acrylic ester).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a polymerizable polyfunctional methacrylic oligomer, and the oligomer obtained by the present invention can be used as a plastic molding material, a paint or a coating material having excellent mechanical properties and optical properties. It can be widely used as a dental material and the like.

[0002]

2. Description of the Related Art Various derivatives of a methacrylic group-containing compound serving as a raw material of a methacrylic resin have been developed. The following reaction formula [1] is obtained by reacting 1,6-hexanediol diacrylate with paraformaldehyde in the presence of 1,4-diazabicyclo [2.2.2] octane (hereinafter, abbreviated as DABCO) to perform polymerization. This is a reaction for obtaining a functional polyfunctional methacryl oligomer. Stansbur
y is to find that a polymerizable polyfunctional methacryl oligomer can be obtained by the reaction of a bifunctional acrylate and formaldehyde as shown in the following reaction formula [1], and to use the reaction product as a dental material or a crosslinking agent. (Reference 1: JWStansbury, Macromolecules, 2
4, 2029 (1991)).

[0003]

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The oligomer obtained by the above reaction formula [1] has a problem of low compatibility with styrene which is a general-purpose monomer, but as shown in the following reaction formula [2], Mathias et al. Reported that by reacting 1,6-hexanediol diacrylate, ethyl acrylate and paraformaldehyde in the presence of DABCO, a polymerizable polyfunctional methacryl oligomer having improved compatibility with styrene can be obtained. (Reference 2: L. Mathias, et al., Macromolecules, 24, 2048
(1991)).

[0005]

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[0006]

The process for producing a polymerizable polyfunctional methacrylic oligomer disclosed in the above-mentioned Reference 2 is based on a method in which a bifunctional acrylate such as 1,6-hexanediol diacrylate is used as a starting material. And 1
When a polyfunctional acrylate having more than two acryloyloxy groups in the molecule is used, there is a problem that an insoluble gel-like substance is generated. The problem of the present invention is that even when a polyfunctional acrylate in which the number of acryloyloxy groups in one molecule exceeds 2 is used as a starting material, an insoluble gel-like substance is not generated and the compound is soluble in a general-purpose solvent. It is an object of the present invention to provide a method for producing a polymerizable polyfunctional methacryl oligomer.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the use of a specific solvent is an effective means, and completed the present invention. I came to. That is, in the present invention, the number of carbon atoms is 1
(A) per mole of a polyfunctional acrylate represented by the following formula [1] in the presence of a basic catalyst in an alcohol solvent of (b) to (b): a monofunctional represented by the following formula [2] A process for producing a polymerizable polyfunctional methacrylic oligomer, comprising reacting an acrylic acid ester with P moles and (c) formaldehyde or an equivalent thereof with Q moles. Here, P and Q are numbers satisfying the following.

[0008]

(Equation 2)

[0009]

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[0010]

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[0011]

BEST MODE FOR CARRYING OUT THE INVENTION (A) Reaction raw materials The reaction raw materials in the present invention are (a) a polyfunctional acrylate ester having more than 2 acryloyloxy groups in one molecule, and (b) acryloyloxy group in one molecule. It is a monofunctional acrylate having one group and (c) formaldehyde or an equivalent thereof.

(A) Polyfunctional Acrylate The polyfunctional acrylate in the present invention is represented by the following formula [1].

[0013]

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(In the above formula [1], R ¹ is a residue of an acryloyloxy group in the polyfunctional acrylate, and n is a number greater than 2.)

The number n of acryloyloxy groups in one molecule of the polyfunctional acrylate may be different for each molecule, and the number n in the present invention is n in each molecule.
Is the average value of Therefore, n in the present invention may be a number other than an integer, and preferably n is 3 to 6.
A polyfunctional acrylate having too large n becomes difficult to dissolve in the alcohol solvent used in the present invention, and may not sufficiently exert the effects of the present invention. Preferred specific examples of the polyfunctional acrylate include the following. (Where n is 3): pentaerythritol triacrylate (trade name: Aronix M, manufactured by Toagosei Co., Ltd.)
305, Kyoeisha Chemical Co., Ltd. product name: Light Acrylate PE-3A), trimethylolpropane triacrylate (Toagosei Co., Ltd. product name: Aronix M3)
09, Kyoeisha Chemical Co., Ltd. product name: Light Acrylate TMP-A), trimethylolpropane EO modified triacrylate (Toagosei Co., Ltd. product name: Aronix M350 or M360, Kyoeisha Chemical Co., Ltd. product name: Light Acrylate TMP-) 6EO-3A or T
MP-3EO-A), trimethylolpropane PO-modified triacrylate (trade name: Aronix M310 or M320, manufactured by Toagosei Co., Ltd.), isocyanuric acid E
O-modified triacrylate (trade name, manufactured by Toagosei Co., Ltd.)
Aronix M315). (Where n is 3.6): phenol novolak type epoxy acrylate (trade name: Showa High Polymer SP401)
0). (Where n is 4): pentaerythritol tetraacrylate (trade name: Alonix M450, manufactured by Toagosei Co., Ltd .; light acrylate PE-4A, manufactured by Kyoeisha Chemical Co., Ltd.), ditrimethylolpropane tetraacrylate (Toagosei Co., Ltd.) Product name: Aronix M408, product name: Kyoeisha Chemical Co., Ltd .: light acrylate DTMP-4A). (Where n is 6): dipentaerythritol hexaacrylate (trade name, manufactured by Toagosei Co., Ltd .: Aronix M400 or M401B, trade name, manufactured by Kyoeisha Chemical Co., Ltd .: light acrylate DPE-6A) and the like. These polyfunctional acrylates can be used alone or in combination.

(B) Monofunctional acrylate The monofunctional acrylate in the present invention is represented by the following formula [2].

[0017]

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(In the above formula [2], R ² is a residue of an acryloyloxy group in the monofunctional acrylate.)

Preferred monofunctional acrylates are those soluble in the alcohol solvent used in the present invention. Specific examples of preferred monofunctional acrylates include the following. That is, methyl acrylate, ethyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, stearyl acrylate, benzyl acrylate, cyclohexyl acrylate, isobornyl acrylate, tricyclodecanyl acrylate , Dicyclopentadienyl acrylate, adamantyl acrylate, 2-hydroxyethyl acrylate, and the like, and these can be used alone or in combination.

(A.3) Formaldehyde or its equivalent The formaldehyde equivalent in the present invention behaves the same as formaldehyde as a raw material for the reaction. Examples include semi-acetals derived from formaldehyde and alcohols having 1 to 6 carbon atoms, and paraformaldehyde which is a polymer of formaldehyde.

(B) Catalyst The catalyst in the present invention is a basic catalyst. Preferred specific examples are triethylamine, quinuclidine, 1,4-
Diazabicyclo [2.2.2] octane (DABC
O), tertiary amines such as 1,8-diazabicyclo [5.4.0] undecene-7 (DBU), hexamethylenetetramine, triphenylphosphine, tributylphosphine, 1,2-bis (diphenylphosphine) ethane and the like And basic ion exchange resins (trade name: Amberlite IRA-68, etc.). Among them, DABCO can be particularly preferably used. These basic catalysts can be used alone or in combination.

(C) Solvent The solvent used in the present invention is an alcohol solvent having 1 to 6 carbon atoms. The production method of the present invention is characterized in that it is carried out in the above-mentioned specific solvent, and if the above-mentioned solvent is not used, there is a problem that a gel-like substance insoluble in a general-purpose solvent is generated in a reaction product. is there. Preferred alcohol solvents are alcohol solvents having 1 to 5 carbon atoms,
It has a boiling point of 60 to 100 ° C. Preferred specific examples include methanol, ethanol, n-propanol, n
-Butanol, n-pentanol, n-hexanol,
i-propyl alcohol, i-butyl alcohol, t-
Alkyl alcohols such as butyl alcohol, t-amyl alcohol and neopentyl alcohol; cycloalkyl alcohols such as cyclopentanol and cyclohexanol; unsaturated alkyl alcohols such as allyl alcohol; and methanol, ethanol, i-propyl alcohol and t -Butyl alcohol and the like can be particularly preferably used. These solvents can be used alone or as a mixture.

(D) Reaction conditions (d) Reaction molar ratio The reaction molar ratio of the polyfunctional acrylate, monofunctional acrylate and formaldehyde in the present invention is 1: P: Q, and the preferred reaction molar ratio is Is 1:
n: 2n. Here, P and Q are numbers satisfying the following.

[0024]

(Equation 3)

(Where n is a polyfunctional acrylate 1)
This is the number of acryloyloxy groups in the molecule, and has the same meaning as n in the above formula [1]).

(D) Amount of Catalyst The preferred amount of the basic catalyst used in the present invention is 1 to 100 mol%, more preferably 3 to 30 mol%, based on all acryloyloxy groups in the reaction system. Mol%. If the amount of the catalyst used is too small, the progress of the reaction becomes insufficient,
Further, even when used in a large excess, the effect is slightly improved.

(D) Amount of Solvent Used The amount of the solvent used is 0.1 to 10 times, preferably 0.1 to 10 times the sum of the weights of the polyfunctional acrylate and the monofunctional acrylate. 5 to 5 times the amount. If the amount of the solvent used is small, the effect of the present invention may not be sufficiently obtained, and if the amount is too large, it may take a long time for the reaction to proceed.

(D) Method of charging reaction raw materials, catalyst and solvent There is no particular limitation on the order of charging the reaction raw materials, catalyst and solvent. A preferred charging order is a method in which a reaction raw material and a solvent are first charged into a reaction vessel, and then a catalyst is added.

(D) Reaction temperature / reaction time The preferred reaction temperature in the present invention is in the temperature range of 0 to 150 ° C., and the preferred reaction time is usually several hours to several tens of hours.

(D.6) Desired additives In carrying out the production method of the present invention, additives such as a colorant, a polymerization inhibitor and a storage stabilizer are appropriately compounded within a range not to impair the effects of the present invention. Can be.

(E) Reaction product The reaction product obtained by the production method of the present invention is a polymerizable polyfunctional methacryl oligomer, which has a plurality of double bonds in the molecule, and is heated, irradiated with ultraviolet light, electron beam. And polymerization by irradiation with active energy rays such as X-rays. Further, by reacting the three types of raw materials used in the present invention, a structural unit represented by the following formula (3) is formed in the polymerizable polyfunctional methacryl oligomer obtained by the present invention, and the structural unit is a cyclic ether during polymerization. To form Therefore, the polymer of the polymerizable polyfunctional methacryl oligomer obtained by the present invention has heat resistance.

[0032]

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(R ¹ and R ² in the above equation are the same as those in the above equation [1]
It has the same meaning as in [2]. An example of a preferable polymerizable polyfunctional methacrylic oligomer obtained by the production method of the present invention is represented by the following formula [4].

[0034]

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(In the above formula [4], R ¹ is a residue of an acryloyloxy group in a polyfunctional acrylate, R ² is a residue of an acryloyloxy group in a monofunctional acrylate, and a and b are All are zero or positive numbers, c is a number greater than 2, and a, b, and c are numbers satisfying a + b + c = n, where n is the same as n in the above formula [1]. )

In the production method of the present invention, since the amount of formaldehyde which reacts with one molecule of the polyfunctional acrylate varies depending on the molecule of the polyfunctional acrylate, the reaction product is usually a mixture. When a polyfunctional acrylate in which the number of acryloyloxy groups per molecule is n is used as a reaction raw material, as described above, the most preferable reaction molar ratio (polyfunctional acrylate: monofunctional acrylate: formaldehyde) Is 1:
n: 2n. If polyfunctional acrylate 1
If the reactive molecular ratio of formaldehyde per molecule is less than 2n, unreacted acryloyloxy groups remain in the polyfunctional acrylate or monofunctional acrylate (corresponding to the case where a in the formula [4] is positive). If the reaction molecular ratio of monofunctional acrylate per molecule of polyfunctional acrylate is smaller than n,
Some acryloyloxy groups in the polyfunctional acrylate ester remain in a state in which one molecule of formaldehyde has reacted, and a hydroxyl group is generated at the terminal (corresponding to the case where b in the above formula [4] is positive).

A preferred reaction product obtained by the production method of the present invention has a viscosity at 40 ° C. of 100,000 cps or less as measured by a B-type viscometer, and more preferably a and b in the above formula [4]. Is zero. Specific examples are shown below. (When the polyfunctional acrylate is trifunctional)

[0038]

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(When the polyfunctional acrylate is tetrafunctional)

[0040]

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[0041]

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(When the polyfunctional acrylate is hexafunctional)

[0043]

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The polymerizable polyfunctional methacrylic oligomer obtained by the present invention is usually soluble in a general-purpose solvent having a boiling point of 60 to 120 ° C. Specific examples of general-purpose solvents include toluene, acetone, tetrahydrofuran, methyl ethyl ketone, and the like.

(F) Purification method The polymerizable polyfunctional methacrylic oligomer obtained by the present invention can be used, if necessary, by a known method, that is, solvent extraction,
It can be easily purified by gel osmotic pressure chromatography or the like.

[0046]

The present invention will be described more specifically with reference to the following examples. [Example 1] Phenol novolak type epoxy acrylate (trade name: SP4010, manufactured by Showa Polymer Co., Ltd.)
153 g (166 mm, 3.6 functional, theoretical molecular weight 920)
ol), 125 g of isobornyl acrylate (600 m
mol), 37.9 g of 95% paraformaldehyde
(1.20 mol), DABCO 13.5 g (120
mmol), 280 g of isopropyl alcohol and 0.2 g of hydroquinone at room temperature for 24 hours,
Stirred at 50 ° C. for 24 hours. In addition, 105
C. and remove isopropyl alcohol by distillation.
Stirred for hours. After cooling to 60 ° C, ethyl acetate 700
ml and 300 ml of methanol were added and stirred to dissolve the reaction mixture. Next, after allowing to cool to room temperature, the mixture was sequentially washed with 300 ml of 0.5N hydrochloric acid and 300 ml of saturated saline, and the obtained organic layer was concentrated to obtain 152 g of a yellow-brown liquid polymerizable polyfunctional methacryl oligomer. The weight average molecular weight of the obtained polymerizable polyfunctional methacryl oligomer by gel osmotic pressure chromatography using polystyrene as a standard was 1,400. The viscosity at 40 ° C. was 24000 cps (B-type viscometer). FIG. 1 shows a chart of an infrared absorption spectrum of the obtained polymerizable polyfunctional methacryl oligomer. 16 in FIG.
The absorption at 34 cm ^-1 is due to a carbon-carbon double bond derived from an acryloyloxy group in a polyfunctional acrylate or a monofunctional acrylate, and
The absorption of ^-1 is due to an ether bond derived from the reaction of formaldehyde. It was confirmed that the obtained polymerizable polyfunctional methacryl oligomer was soluble in methyl ethyl ketone or tetrahydrofuran. 1 part of benzyldimethyl ketal as a photoinitiator was dissolved in 100 parts of the obtained polymerizable polyfunctional methacrylic oligomer, and this was poured into a Teflon mold (50 × 25 × 2 mm), and a 60 W / cm high-pressure mercury type UV lamp was used. A cured product was obtained by performing ultraviolet irradiation under the conditions of parallel type irradiation at a lamp height of 30 cm for 60 seconds.

Example 2 57.9 g (100 mmol) of dipentaerythritol hexaacrylate (trade name: Aronix M401B manufactured by Toagosei Co., Ltd.), 125 g (600 mmol) of isobornyl acrylate, 95
% Paraformaldehyde 37.9 g (1.20 mo
1), 13.5 g (120 mmol) of DABCO, 366 g of isopropyl alcohol and hydroquinone
0.1 g was stirred at 50 ° C. for 20 hours in an air stream. Further, while distilling off isopropyl alcohol, 100 ° C
For 5.5 hours. After allowing to cool to 60 ° C., 500 ml of ethyl acetate and 200 ml of methanol were added and stirred to dissolve the reaction mixture. Next, after cooling to room temperature,
300 ml of 0.5N hydrochloric acid and 300 ml of saturated saline
, And by concentrating the obtained organic layer,
Yellowish-brown liquid polymerizable polyfunctional methacryl oligomer 94
g was obtained. The weight average molecular weight of the obtained polymerizable polyfunctional methacryl oligomer by gel osmotic pressure chromatography using polystyrene as a standard was 1,400. 2
The viscosity at 5 ° C. was 2500 cps (B-type viscometer). FIG. 2 shows a chart of an infrared absorption spectrum of the obtained polymerizable polyfunctional methacryl oligomer. The absorption at 1637 cm ^-1 in FIG. 2 is due to a carbon-carbon double bond derived from an acryloyloxy group in a polyfunctional acrylate or a monofunctional acrylate;
The absorption at 1108 cm ^-1 is due to the ether linkage from the formaldehyde reaction. It was confirmed that the obtained polymerizable polyfunctional methacryl oligomer was soluble in methyl ethyl ketone or tetrahydrofuran. Based on 100 parts of the resulting polymerizable polyfunctional methacrylic oligomer, t-butyl peroxybenzoate 3 was used as a radical initiator.
The melted part was poured into a Teflon mold (50 × 25 × 2 mm) and heated at 150 ° C. for 1 hour to obtain a cured product.

Example 3 57.9 g (100 mmol) of dipentaerythritol hexaacrylate (trade name: Aronix M401B, manufactured by Toagosei Co., Ltd.), 76.9 g (600 mmol) of isobutyl acrylate, 95
% Paraformaldehyde 37.9 g (1.20 mo
1), DABCO 13.5 g (120 mmol), isopropyl alcohol 270 g and hydroquinone
0.1 g was stirred at 50 ° C. for 20 hours in an air stream. Further, while distilling off isopropyl alcohol, 100 ° C
For 4.5 hours. After allowing to cool to 60 ° C., 500 ml of ethyl acetate and 200 ml of methanol were added and stirred to dissolve the reaction mixture. Next, after cooling to room temperature,
300 ml of 0.5N hydrochloric acid and 300 ml of saturated saline
, And by concentrating the obtained organic layer,
86 g of a yellow-brown liquid polymerizable polyfunctional methacryl oligomer
I got The weight average molecular weight of the obtained polymerizable polyfunctional methacryl oligomer by gel osmotic pressure chromatography using polystyrene as a standard was 1600. 2
The viscosity at 5 ° C. was 5,300 cps (B-type viscometer). It was confirmed that the obtained polymerizable polyfunctional methacryl oligomer was soluble in methyl ethyl ketone or tetrahydrofuran.

Example 4 57.9 g (100 mmol) of dipentaerythritol hexaacrylate (trade name: Aronix M401B manufactured by Toagosei Co., Ltd.), 60.1 g (600 mmol) of ethyl acrylate, 95%
Paraformaldehyde 37.9 g (1.20 mo
1), DABCO 13.5 g (120 mmol), isopropyl alcohol 236 g and hydroquinone
0.1 g was stirred at 50 ° C. for 20 hours in an air stream. Further, while distilling off isopropyl alcohol, 100 ° C
For 4.5 hours. After allowing to cool to 60 ° C., 500 ml of ethyl acetate and 200 ml of methanol were added and stirred to dissolve the reaction mixture. Next, after cooling to room temperature,
300 ml of 0.5N hydrochloric acid and 300 ml of saturated saline
, And by concentrating the obtained organic layer,
Yellow-brown liquid polymerizable polyfunctional methacryl oligomer 80
g was obtained. The weight average molecular weight of the obtained polymerizable polyfunctional methacryl oligomer by gel osmotic pressure chromatography using polystyrene as a standard was 1,700. 25
The viscosity at ° C was 16000 cps (B-type viscometer). It was confirmed that the obtained polymerizable polyfunctional methacryl oligomer was soluble in methyl ethyl ketone or tetrahydrofuran.

Example 5 38.6 g (66.7 mmol) of dipentaerythritol hexaacrylate (trade name: Aronix M401B manufactured by Toagosei Co., Ltd.), 120 g (1.20 mol) of ethyl acrylate, 37%
130 g (1.60 mol) of formalin aqueous solution, DA
18.0 g (160 mmol) of BCO, 311 g of isopropyl alcohol and 0.1 g of hydroquinone were stirred at room temperature for 90 hours in an air stream. Further, the mixture was stirred at 105 ° C. for 6.5 hours while distilling off isopropyl alcohol. After cooling to 60 ° C, ethyl acetate 600ml
And 300 ml of methanol were added and stirred to dissolve the reaction mixture. Next, after allowing to cool to room temperature, 0.5N hydrochloric acid 4
00 ml and a saturated saline solution 300 ml in order,
By concentrating the obtained organic layer, 50 g of a yellowish brown liquid polymerizable polyfunctional methacryl oligomer was obtained. The weight average molecular weight of the obtained polymerizable polyfunctional methacryl oligomer by gel osmotic pressure chromatography using polystyrene as a standard was 1,400. It was confirmed that the obtained polymerizable polyfunctional methacryl oligomer was soluble in methyl ethyl ketone or tetrahydrofuran.

Comparative Example 1 A reaction was carried out in the same manner as in Example 1 except that isopropyl alcohol was not used. As a result, an insoluble compound insoluble in methyl ethyl ketone or tetrahydrofuran was quantitatively produced.

Comparative Example 2 A reaction was carried out in the same manner as in Example 4 except that isopropyl alcohol was not used. As a result, an insoluble compound insoluble in methyl ethyl ketone or tetrahydrofuran was quantitatively produced.

[0053]

Industrial Applicability According to the production method of the present invention, a polymerizable polyfunctional methacryl oligomer starting from a polyfunctional acrylate, formaldehyde, or a monofunctional acrylate can be produced without producing a compound insoluble in a general-purpose solvent. Can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a chart of an infrared absorption spectrum of a polymerizable polyfunctional methacryl oligomer obtained in Example 1.

FIG. 2 is a chart of an infrared absorption spectrum of the polymerizable polyfunctional methacryl oligomer obtained in Example 2.

Claims (1)

[Claims] In an alcohol solvent having 1 to 6 carbon atoms, (a) per mole of a polyfunctional acrylate represented by the following formula [1] in the presence of a basic catalyst:
(b) A method for producing a polymerizable polyfunctional methacryl oligomer, which comprises reacting a monofunctional acrylate represented by the following formula [2] with P mole and (c) formaldehyde or its equivalent with Q mole. Here, P and Q are numbers satisfying the following. (Equation 1) (In the above formula, n has the same meaning as n in the following formula [1].) Embedded image