JPH0749461B2 - Method for producing radically curable resin - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a radical-curable resin.

[Conventional technology and problems]

Radical curable resins are widely used and are useful, for example, unsaturated polyester resins and vinyl ester resins. However, even with these resins, there are some situations in which they cannot necessarily be applied as their applications expand. For example, a molded product having a high degree of rubber elasticity, or a high toughness resin having both elongation and strength is desired to have further higher properties, and these radical-curable resins already existing as an adhesive are , Does not always have sufficient performance.

The inventors of the present invention have achieved the present invention as a result of solving the above problems and continuing to earnestly study a resin applicable to a field which cannot be achieved by a conventional radical curable resin.

[Means for Solving the Problems]

That is, the present invention provides: (a) a saturated polyester having an end group substantially an isocyanate group and a number average molecular weight of 5000 or more; and (b) at least two (meth) acryloyl groups and a hydroxyl group in one molecule. The present invention aims to solve the above-mentioned problems by providing a method for producing a radical-curable resin, which comprises reacting a vinyl ester resin having

The present invention will be described in detail below.

First, in order to facilitate the understanding of the present invention, the reaction between the component (a) and the component (b) will be illustrated by the following formula.

The radical-curable resin according to the present invention comprises a saturated polyester (hereinafter abbreviated as polyester) or a type of terminal isocyanate group in the component (a), a type of vinyl ester of the component (b), and (a), ( By changing the blending ratio of b), it is possible to impart a wide range of physical properties.

Component (a): Polyester whose terminal group has a substantially isocyanate group The component (a) used in the present invention, the polyester whose terminal group is a substantially isocyanate group, is a polyester whose terminal group is a hydroxyl group. A diisocyanate having two differently reactive isocyanate groups, eg 2,
It can be easily synthesized by reacting 4-tolylene diisocyanate and isophorone diisocyanate. This synthesis can be carried out in a solvent or a monomer, and it is more advantageous to use a urethanization reaction catalyst.

In the present invention, the number average molecular weight of the component (a) polyester is 5000 or more (hereinafter abbreviated as high molecular weight polyester).
Is one of the conditions. When the molecular weight is small, it is disadvantageous in the expression of rubber elasticity, and a high elongation cannot be expected even with high strength, and the meaning of the present invention is lost.

The constitution of the polyester does not need to be particularly limited, and examples of the raw materials used include the following.

Ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, 3-methylpentanediol 1,5, butanediol 1,3, butanediol 1,4, pentanediol 1,
5, hexanediol 1,6, hydrogenated bisphenol A, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, trimethylolpropane, pentaerythritol.

Alkylene monoepoxides such as ethylene oxide,
Propylene oxide, styrene oxide, butylene oxide, phenyl glycidyl ether, epichlorohydrin and the like can also be used as the polyester raw material in the same manner as the polyhydric alcohol.

Moreover, each type of saturated polycarboxylic acid can be used. For example, isophthalic acid, terephthalic acid or dimethyl ester, phthalic acid, succinic acid, adipic acid, sebacic acid, dodecanoic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, trimellitic anhydride.

In order to synthesize a high molecular weight polyester, simple esterification alone is difficult and must be finally carried out by a deglycolization reaction. The use of a suitable reaction catalyst for this is necessary.

According to the reaction mode, since the terminal group of the synthesized high molecular weight polyester is substantially a hydroxyl group, it can be reacted with diisocyanate to obtain a high molecular weight polyester having an isocyanate group terminal.

The reaction is carried out by dissolving polyester in a monomer or a solvent.

As the kind of diisocyanate, as described above, 2,4-tolylene diisocyanate and isophorone diisocyanate having different reactivity of two isocyanate groups are preferable, but other isocyanates such as diphenylmethane diisocyanate are preferable. Isocyanate, hexamethylene diisocyanate, xylylene diisocyanate and the like can also be used by selecting the reaction conditions.

Component (b): vinyl ester resin having a (meth) acryloyl group and a hydroxyl group in the molecule. The vinyl ester resin used as the component (b) of the present invention to react with a high molecular weight polyester having an isocyanate group terminal is as follows. There are different types.

(1) A bisphenol type epoxy resin, a novolac type epoxy resin, or an alicyclic epoxy resin is reacted with (meth) acrylic acid.

(2) Glycidyl methacrylate is reacted with polyhydric phenols or novolacs.

The type in which (meth) acrylic acid is reacted with an epoxy resin is convenient because an oligoacrylate type having a molecular weight of 1000 or less does not increase the viscosity of the produced resin. Conversely, when a high-viscosity resin is desired, a molecular weight of 1000 or more is desirable. Types can also be used.

The epoxy resin does not need to be particularly limited.

Reaction Ratio of Component (a) and Component (b) The ratio of the bidroxyl group of the vinyl ester resin which is the component (b) to the isocyanate group of the high molecular weight polyester which is the component (a) is based on 1 equivalent of the hydroxyl group. The isocyanate group is 0.5 equivalent or more and 1 equivalent or less, but is 0.1 equivalent or more when an advantage is found in the method of using a vinyl ester resin in combination.

When the ratios are substantially the same, the calculated molecular weight becomes infinite, and molding cannot be performed. However, when the mixture is molded and applied or molded, it can be applied.

When the amount of the isocyanate group is large, that is, when the hydroxyl group is 1 equivalent or more per 1 equivalent of the hydroxyl group,
When the amount does not exceed 1 equivalent, if it is substantially 1.5 equivalents or less, the same physical property as that of 1 equivalent is given, and therefore the same treatment is performed.

The radically curable resin having a vinyl ester structure through a urethane bond at the terminal of a high molecular weight polyester according to the present invention is dissolved in a copolymerizable monomer and molded, or dissolved in a solvent and applied and dried. Only the polymer can be used as a coating or an adhesive.

Needless to say, the resin according to the present invention can be used in combination with a reinforcing material, a filler, a colorant, a release agent, a thermoplastic polymer, etc. when used.

〔Example〕

Next, in order to help understanding of the present invention, examples will be shown below.

Example 1 Synthesis of High Molecular Weight Polyester (A) Having Terminal Isocyanato Group 350 g of propylene glycol, 388 g of dimethyl terephthalate and 2 g of zinc acetate were charged into a two-necked flask equipped with a stirrer, a fractionating condenser, a gas introduction tube and a thermometer. , 180
~ 185 ℃, proceed with the demethanol reaction in a nitrogen stream, at the point where the distillation of methanol has stopped, change to a direct distillation condenser, add tetraisopropyl methane 1g, temperature 210 ~ 220 ℃, 0.
After deglycolization for 8 hours under reduced pressure of 5 to 1.0 Torr, 0.13 g of p-benzoquinone and 650 g of styrene at a temperature of 160 ° C.
Was added and dissolved uniformly.

The acid value of the obtained polyester was substantially zero, the hydroxyl value was about 4 to 5, and GPC analysis revealed that a high molecular weight polyester having a peak at an average molecular weight of about 10500 was obtained.

To this, add 12 g of 2,4-tolylene diisocyanate and add 65
When the reaction was carried out at ˜70 ° C. for 3 hours, it was determined by infrared analysis that the concentration of the isocyanate group was reduced by about half.

An isocyanate-terminated high molecular weight polyester (A) was obtained with Hazen color paper 150 and a viscosity of 9.1 poise.

Synthesis of vinyl ester resin (B) In a one-separable flask equipped with a stirrer, reflux condenser and thermometer, epoxy resin 355 with epoxy equivalent of 176
g, 172 g of methacrylic acid, 1.5 g of trimethylbenzylammonium chloride, 0.25 g of hydroquinone, 130
Since the acid value became approximately 3 after reacting at ˜135 ° C. for 3 hours, 370 g of styrene was added to obtain vinyl ester resin (B) with Hazen color paper 450 and viscosity 1.8 poise.

Synthesis of polyester (C) having vinyl ester structure at the terminal through urethane bond 85 g of vinyl ester resin (B) (NCO / OH≈1) is added to the total amount of the polyester (A) having an isocyanate group terminal as described above.
/ 2), add 1 g of dibutyltin dilaurate, and add 3 at 65-70 ℃.
After reacting for a period of time, infrared analysis confirmed that free isocyanate groups had disappeared.

A desired high molecular weight polyester (I) having a vinyl ester structure at the end was obtained with a Gardner color number of 3 and a viscosity of 29.3 poise.

To 100 parts by weight of polyester (I) (the weight is omitted below),
Styrene 7 parts, methyl ethyl ketone peroxide 1.5
Parts, 0.5 part of cobalt naphthenate, acetoacetoylpyrrolidine [Nafthrator PIK manufactured by Nippon Emulsifier Co., Ltd.]
The system to which 0.3 part was added generated mild heat after gelling at room temperature in 16 minutes, and the maximum heat generation temperature was 134 ° C.

As shown in Table 1, the physical properties of the test pieces molded into desired dimensions (post-curing at 100 ° C. for 2 hours) were excellent.

Example 2 High molecular weight polyester (C) containing terminal isocyanate groups
Of propylene glycol 182g, 3-methylpentanediol 1,5 260g, and adipic acid 584g were charged into a 2 flask equipped with a stirrer, a fractionating condenser, a thermometer, and a gas introduction tube, and 180-200 ° C in a nitrogen stream. After esterification to an acid value of 9.1 with 2.6 g of tetraisopropyl titanate and reacting for 6 hours under a reduced pressure of 210 to 220 ° C and 0.8 to 1.0 Torr, a hydroxyl value of about 6 and a polyester with a molecular weight of 11600 by GP analysis Was synthesized.

This was dissolved in 880 g of methyl methacrylate and 0.3 g of hydroquinone, 37 g of isophorone diisocyanate and 2.7 g of dibutyltin dilaurate were added, and the mixture was reacted at 60 to 65 ° C for 5 hours,
Infrared analysis confirmed that the isocyanate group was halved.

Synthesis of vinyl ester resin (D) In a one-separable flask equipped with a stirrer, a reflux condenser, and a thermometer, 380 g of Dow Chemical's DEN-431 as a novolac type epoxy resin, 144 g of acrylic acid, 1.5 g of benzyldimethylamine, When 0.25 g of hydroquinone was added and reacted at 120 to 125 ° C. for 3 hours, the acid value became almost zero. 375 g of methyl methacrylate was added, and a vinyl ester resin (D) was obtained with a Gardner color number of 3 to 4 and a viscosity of 1.8 poise.

To the total amount of the terminal isocyanate group polyester (C),
When 120 g of vinyl ester resin (D) was added and further reacted at 65 to 70 ° C. for 5 hours, it was confirmed by infrared analysis that the free isocyanate group disappeared.

High-molecular-weight polyester (II) containing the desired vinyl ester structure at the end by adding 70 g of methyl methacrylate
(Methyl methacrylate solution) was obtained.

The Gardner color number was 3 and the viscosity was 9.4 poise.

100 parts of polyester (II), 1.5 parts of benzoyl peroxide,
The system to which 0.3 part of dimethylaniline was added gelled in about 20 minutes.

Tensile strength of the sample after curing at 80 ℃ for 2 hours and 120 ℃ for 2 hours 2
The tensile elongation was 10 to 250 kg / cm ² , and the tensile elongation was 434 to 510 (%).

Example 3 Synthesis of High Molecular Weight Polyester (E) whose End Group is Substantially Isocyanate Group In a two four-necked flask equipped with a stirrer, a fractionating condenser, a gas introduction tube and a thermometer, 182 g of propylene glycol,
Charge 216 g of butanediol 1,4 and 332 g of isophthalic acid, proceed with esterification at 180-190 ° C, add 404 g of sebacic acid at an acid value of 20.9, and continue the reaction.
Esterification proceeds at 190-210 ° C under reduced pressure of ~ 12 Torr to obtain acid value.
7.8 (number average molecular weight of about 2200).

At this stage, add 2 g of tetraisopropyl titanate and
A polyester having a number average molecular weight of 12700 was obtained by deglycolizing at 200 to 210 ° C. under a reduced pressure of 0.9 to 1.1 Torr for 5 hours. Dehydrated methyl ethyl ketone 600g, toluene 40
After dissolving in 0 g of mixed solvent, isophorone diisocyanate 60
When 3 g of dibutyltin dilaurate and 3 g of dibutyltin dilaurate were added and reacted at 60 to 65 ° C for 5 hours, it was estimated by infrared analysis that the free isocyanate groups were almost halved, and the polyester (E) having a terminal isocyanate group (mixed solvent Solution) was obtained as a pale tan color.

Synthesis of vinyl ester (F) In a one-separable flask equipped with a stirrer, a reflux condenser, and a thermometer, 270 g of ERL-4221 manufactured by Union Carbide Company of the United States as an alicyclic epoxy resin and 144 acrylic acid
g, parabenzoquinone 0.08 g, and trimethylbenzylammonium chloride 1.2 g were charged, and when the reaction was carried out at 125 to 130 ° C for 3 hours, the acid value became substantially zero.
The temperature was lowered to ℃, 386 g of the mixed solvent of toluene and methyl ethyl ketone was added, and vinyl ester (F) was obtained as a pale reddish brown liquid.

Manufacturing and physical properties of curable adhesive tape 100 parts by weight of polyester (E) (mixed solvent solution) (OH /
NCO ≒ 1/1), 8 parts by weight of vinyl ester (F) and 1 part of tertiary butyl perbenzoate are mixed, and the solid remaining amount is 30 on a polyethylene terephthalate film with a thickness of 50μ.
It was applied so as to have a thickness of μ, and the solvent was volatilized at 80 ° C. for 20 minutes and at 100 ° C. for 10 minutes to give an adhesive film with a slight adhesiveness.

After crimping this to a stainless plate of 150 × 25 × 2m / m up to 75m / m,
It was cured at 150 ° C for 30 seconds.

The 180 ° peel strength of the cured film was 4 kg / in or more, and the film was broken.

Separately, impregnated with a polyester fiber non-woven fabric with a thickness of 0.3 m / m,
Adhesive prepreg mat dried under the same conditions was adhered to an area of 12m / m × 25m / m of stainless steel plates, and the adhesive strength by tensile shearing at room temperature after pressure-curing at 150 ℃ for 3 minutes was 112-154kg. / cm ² was shown.

〔The invention's effect〕

Since the present invention is configured as described above, it is possible to easily obtain a cured resin having a high toughness, which is easily radical-cured and has a good balance between elongation and strength. Further, a curable resin useful as an adhesive can be obtained.

Claims (1)

[Claims] 1. A saturated polyester having a terminal group which is substantially an isocyanate group and a number average molecular weight of 5000 or more, and (b) at least two (meth) acryloyl groups and a hydroxyl group in one molecule. A method for producing a radical-curable resin, which comprises reacting a vinyl ester resin having