JP2000109527A - Curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition capable of producing an acrylic resin having excellent impact resistance. SOLUTION: This curing composition comprises methyl methacrylate and the dimethacrylate of a dimerdiol-alkylene oxide adduct. The dimethacrylate of the dimerdiol-alkylene oxide adduct includes various compounds, and is preferably the dimethacrylate of a dimerdiol-alkylene oxide adduct (hereinafter referred to as a modified diol) represented by the general formula: HO-(XO)m- ZO-(YO)n-H [Z is a dimerdiol residue; X and Y are each the same or different 2-4C alkylene group; (m), (n) are each 0 or the same or different integer, provided that 2<=(m)+(n)<=40].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent acrylic plate excellent in transparency and impact resistance, an artificial marble excellent in water resistance and aesthetic appearance, and a cured product capable of producing a cured product applicable to road pavement materials. The present invention relates to a water-soluble composition and can be awarded in these technical fields.

[0002]

2. Description of the Related Art Disadvantages of a polymethyl methacrylate resin (hereinafter sometimes referred to as an acrylic resin) produced by casting polymerization, such as a transparent acrylic plate or artificial marble, are given as drawbacks. Has a lack of impact resistance. Causes of insufficient impact resistance include brittleness of the resin itself and internal stress during curing.

As a means for improving the impact resistance of an acrylic resin, a composition containing a high-molecular-weight anti-shrinkage agent is known (JP-A-3-185021, JP-A-5-124844). . However, since the shrinkage inhibitor used in the composition does not participate in the curing reaction of the composition, there is a problem that the elasticity and rigidity of the cured product obtained after curing are reduced. There is also a composition to which a macromonomer is added (JP-A-8-135802). In this case, too, since the macromonomer has a large molecular weight and is monofunctional, unreacted macromonomer is contained in the cured product. It easily remained and had the same problem as the composition containing the anti-shrinkage agent. There is also a composition containing a polyfunctional low molecular weight monomer (JP-A-8-231610), but in this case, the thermoplasticity of the obtained cured product is reduced, and the viscosity is high even when the cured product is melted at a high temperature. Therefore, there is a problem that moldability such as injection molding is deteriorated. There is also a composition containing dimer diol dimethacrylate (Japanese Patent Application No. 9-31373), but the copolymerization proceeds efficiently due to low compatibility between polymethyl methacrylate and dimer diol dimethacrylate generated by polymerization. And the impact resistance of the cured product was insufficient.

The present inventors have conducted intensive studies in order to find a composition which can produce an acrylic resin having excellent impact resistance.

[0005]

Means for Solving the Problems As a result of various studies, the present inventors have found that, in order to solve the above-mentioned problems, a composition using a combination of dimethacrylate and methyl methacrylate of an alkylene oxide adduct of dimer diol. The present invention was found to be effective, and the present invention was completed. Hereinafter, the present invention will be described in detail. In this specification, acrylic acid or methacrylic acid is referred to as (meth) acrylic acid, and acrylate or methacrylate is referred to as (meth) acrylate.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As the dimethacrylate of the dimer diol alkylene oxide adduct in the present invention, various compounds can be used, and a preferred example is a dimer diol alkylene oxide adduct represented by the following general formula (1) ( (Hereinafter simply referred to as modified diol).

[0007]

HO- (XO) _m -ZO- (YO) _n -H (1)

In the formula (1), Z is a dimer diol residue, and X and Y are the same or different and have 2 to 4 carbon atoms.
And m and n are the same or different integers of 0 or more, and 2 ≦ m + n ≦ 40.

X and Y are the same or different and have 2 to 4 carbon atoms.
And specific examples thereof include an ethyne group, a propylene group and a butylene group.

The total amount of m + n, that is, dimer diol 1
The ratio of addition of alkylene oxide to the molecule is 2
It is preferable that ≦ m + n ≦ 40. If this value is less than 2, the physical properties of the resulting modified diol are close to those of the dimer diol, the effect of adding the alkylene oxide is insufficient, and the impact resistance of the cured product is insufficient. On the other hand, when it exceeds 40, the molecular weight of the finally obtained modified diol dimethacrylate becomes too large, so that the polymerization rate of the composition may be slowed down.

The modified diol can be produced by adding an alkylene oxide having 2 to 4 carbon atoms to the dimer diol. As dimer diol,
For example, Pespol H commercially available from Toagosei Co., Ltd.
A commercially available product such as P-1000 may be used. As the alkylene oxide having 2 to 4 carbon atoms, ethylene oxide, propylene oxide, butylene oxide and tetrahydrofuran (hereinafter abbreviated as THF) can be used. 3
As a method for producing a modified diol using an alkylene oxide having a membered ring, two hydroxyl groups in the dimer diol are converted to an alcoholate with sodium hydroxide or potassium hydroxide, and this is heated to 100 to 140 ° C. Then, a method in which a predetermined amount of the alkylene oxide is added with stirring to anion-polymerize the dimer diol alcoholate, or the like, may be used. Further, as a method for producing a modified diol using THF as an alkylene oxide, THF is subjected to cationic ring-opening polymerization at about 0 ° C. in the presence of boron trifluoride etherate, followed by disodium salt of dimer diol. Is added to stop the polymerization.

The dimethacrylate of a modified diol (hereinafter simply referred to as dimethacrylate) is produced by subjecting a modified diol and methacrylic acid to a dehydration esterification reaction, or by subjecting a modified diol and methacrylate to dealcoholation and transesterification. I just want it. Preferred examples of the methacrylate used in the transesterification include methyl methacrylate and ethyl methacrylate.

As a method for producing dimethacrylate by an esterification reaction between a modified diol and methacrylic acid, the modified diol and methacrylic acid are reacted in the presence of a catalyst at 60 to 1
For example, a method of heating and mixing at 40 ° C., and in some cases, reducing the pressure and dehydrating may be used. A preferable mixing ratio of methacrylic acid is 2.01 mol or more per 1 mol of the modified diol. If the amount is less than 2.01 mol, unmodified unreacted diol with methacrylic acid remains, which is not preferable. As the catalyst, sulfuric acid, p-toluenesulfonic acid, methanesulfonic acid and the like are used. The addition amount is 0.5 to 10 in the reaction solution.
%, More preferably 0.5 to 5.0% by weight. As a method for producing dimethacrylate by a transesterification reaction between a modified diol and methacrylate, after sufficiently predrying the modified diol, in the presence of a catalyst, the modified diol and methacrylate are mixed by heating at 60 to 140 ° C., and in some cases, A method of reducing pressure and the like can be given. A preferable ratio of the methacrylate is 2.01 mol or more per 1 mol of the modified diol. Examples of the catalyst include tetraethyl titanate, tetraisopropyl titanate, tetrabutyl titanate, and the like.
The content is preferably 0.05 to 5% by weight in the reaction solution. In any of the above reactions, a polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether and 6-t-butyl-2,4-xylenol is added to the reaction solution in an amount of 10 to 1000 pp.
It is preferable to add about m. Further, a solvent such as hexane, toluene, xylene and cyclohexane, or a mixed solvent obtained by mixing two or more of these solvents can be added to the reaction system. The added amount of these solvents is preferably 80% by weight or less based on the total charged amount. 8
If it exceeds 0% by weight, the reaction may be slowed down. The dimethacrylate obtained in this manner has a sterically bulky dimer diol skeleton at the center of the molecule, and thus has a large stress relaxation effect when copolymerized. Further, since the dimethacrylate is ether-modified, it has excellent compatibility with polymethyl methacrylate, and
Since it has two methacryloyl groups, the copolymerization proceeds efficiently, and the impact resistance of the obtained cured product is improved.

The present invention is a composition comprising the above dimethacrylate and methyl methacrylate. A preferred compounding ratio of these components is that dimethacrylate is 0.5 to 3
0 parts by weight, and 99.5 to 70 parts by weight of methyl methacrylate. If the proportion of dimethacrylate is less than 0.5% by weight, the effect of addition may not be exhibited, and the impact resistance of the cured product may be insufficient, while if it exceeds 30% by weight,
Excessive cross-linking gelation may result in reduced moldability. More preferably, dimethacrylate is 1 to 15% by weight.
And 99 to 85 parts by weight of methyl methacrylate.

In the present invention, in addition to the above essential components, a radical polymerizable monomer copolymerizable therewith can be added to such an extent that the effects of the present invention are not impaired. Specific examples include (meth) acrylic acid, methyl acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, and 2-ethylhexyl (meth). Compounds having one radically polymerizable unsaturated group such as acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, styrene, α-methylstyrene, α-methylstyrene dimer and N-methylpyrrolidone;
And 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate,
Dimer diol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polyurethane poly (meth) acrylate, polyester poly (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol poly Compounds having two or more radically polymerizable unsaturated groups such as (meth) acrylate and divinylbenzene are exemplified.

The composition of the present invention is generally used by adding a polymerization initiator to the composition and polymerizing the composition by heating. Examples of the polymerization initiator in this case include organic peroxides such as benzoyl peroxide and lauroyl peroxide, azo compounds such as azobisisobutyronitrile and azobisisovaleronitrile, and redox such as benzoyl peroxide / dimethylaniline. System initiators. A preferable addition amount is 0.1 to 5 parts by weight based on all monomers. Polymerization temperature is 50-140
° C. In the case of a redox system, polymerization is possible even at around room temperature. Uses of the composition of the present invention include transparent acrylic plates, artificial marble, road paving materials, and the like.

[0017]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Reference Examples, Examples and Comparative Examples. Reference Example 1 (Synthesis of modified diol) In a nitrogen-purged autoclave, 100.0 g of dimer diol (hydroxyl value: 197 mgKOH / g)
(0.187 mol) and 40% aqueous solution of potassium hydroxide 5
2.4 g (0.374 mol) were added, and 100 ° C., pressure 5
A dehydration reaction was performed for 3 hours under the condition of mmHg, and the water content was 10
0 ppm of the reaction product was obtained. The reaction is heated to 110
１２０120 ° C. and 49.4 g (1.122) of ethylene oxide under pressure (5 kgf / cm ² ) for 4 hours.
Mol) was added and reacted. After the reaction, cool to 60 ° C,
The pressure was reduced to 10 mmHg to remove residual ethylene oxide. After the reaction product is neutralized with hydrochloric acid, dehydration and filtration are performed, and a modified diol having a hydroxyl value of 140.8 mgKOH / g (number average molecular weight: about 800) (hereinafter, modified diol A)
143 g was obtained. Modified diol A is ¹ H-N
MR analysis revealed that the modified diol was obtained by adding about 6.0 mol of ethylene oxide to 1 mol of the dimer diol.

Reference Example 2 (Synthesis of dimethacrylate) 100 g (0.125 mol) of the obtained modified diol A,
300 g (0.3 mol) of methyl methacrylate, 1 g of tetrabutyl titanate and 0.01 g of hydroquinone monomethyl ether were placed in a flask. While blowing in air and heating to an internal temperature of 105 ° C., 200 g of methyl methacrylate was further added dropwise over 4 hours. During the reaction period, 206 g of a mixture of unreacted methyl methacrylate and methanol produced by the reaction was distilled off. After the reaction, the mixture was cooled to an internal temperature of 60 ° C., 50 g of water was added, and the mixture was stirred for 1 hour. As a result, a precipitate derived from tetrabutyl titanate was formed. The mixture was filtered and separated, and the organic layer was taken out. Unreacted methyl methacrylate was distilled off at 60 ° C. and 5 mmHg. As a result, dimethacrylate of modified diol A (hereinafter simply referred to as dimethacrylate A)
110 g were obtained.

Example 1 Dimethacrylate A / methyl methacrylate mixed solution (5
/ 95 weight ratio) 100 parts, benzoyl peroxide 0.
Five parts were mixed to obtain a composition. The composition was purged with nitrogen, degassed in vacuo, polymerized at 50 ° C. for 7 hours, and further polymerized at 70 ° C. for 3 hours to obtain a cured product. The obtained cured product was evaluated according to the following method. Table 1 shows the results.

Impact resistance: A sample (notched) of 80 × 10 × 4 mm was used according to the method of ASTM D-256.

ASTM D using a sample having a flexural modulus of 80 × 10 × 4 mm
-790.

Example 2, Comparative Examples 1-2 A composition was obtained in the same manner as in Example 1, except that the compositions shown in Table 1 were used. The obtained composition was cured under the same conditions as in Example 1, and the obtained cured product was evaluated in the same manner as in Example 1. Table 1 shows the results.

[0023]

[Table 1] 1) DDDM: dimer diol dimethacrylate 2) BPO: benzoyl peroxide

[0024]

According to the curable composition of the present invention, the cured product obtained is excellent in flexural modulus and impact resistance, and also excellent in moldability.

Claims (1)

[Claims] 1. A curable composition comprising a dimer diol alkylene oxide adduct dimethacrylate and methyl methacrylate.