JP2000344843A - Vinyl ester and flame-retardant resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vinyl ester and a flame-retardant resin composition which have sufficient flame retardancy, heat resistance and water resistance. SOLUTION: The vinyl ester has at least one phosphinic ester structure having (meth)acryloyl groups directly bonded on average to one phosphorus atom in the ester part in one molecule. The flame-retardant resin composition contains a radically polymerizable resin containing the vinyl ester in an amount of 1-99 wt.% based on the total radical-polymerizable resin, with the content of the radical-polymerizable resin being 10-100 wt.% based on the total flame- retardant resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a vinyl ester,
The present invention relates to a flame-retardant resin composition and a cured product thereof.

[0002]

2. Description of the Related Art In the case of using a vinyl ester as a radical-curable resin composition, a vinyl ester can provide a cured product having excellent basic performance after curing. It has come to be.

[0003] Since a cured product obtained by curing a resin composition containing a vinyl ester has an inherently flammable property as an organic substance, it can be used, for example, in the field of molded articles such as building materials. Must provide the flame retardancy required to meet fire protection standards and the like.

[0004] Such flame retardancy is usually imparted by blending a flame retardant. Particularly, when a halogen-based flame retardant is used, an oxidation reaction when the resin burns is prevented. It is widely used because it is extremely effective. It is generally said that in order to exhibit sufficient flame retardancy, it is better to mix the resin composition so that the ratio of halogen atoms in the resin composition is 15% by weight or more. However, a cured product containing a large amount of halogen atoms obtained by curing the resin composition, although it is possible to obtain certain flame retardancy, generates highly toxic dioxin when discarded and burned after it becomes unnecessary. And may pollute the environment.

Therefore, it is known to use a phosphorus-based flame retardant such as triphenylphosphine as a non-halogen-based flame retardant. By blending a phosphorus-based flame retardant into the resin composition, a film of polyphosphoric acid is formed on the surface of the resin by decomposition and thermal condensation during combustion, and the flame retardancy is reduced by the effect of shielding oxygen by the film. It will be applied to the cured product.

However, in general, such phosphorus-based flame retardants are so-called additive types which are simply blended in a resin composition, and therefore, a cured product using the same is heat-resistant and water-resistant. There was a possibility that physical properties such as properties, electrical properties, and mechanical properties would be reduced. Further, when the resin composition is cured or over time, the flame retardant bleeds on the surface of the cured product, and there is a possibility that uniform flame retardancy cannot be obtained in the cured product.

[0007]

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a vinyl ester and a flame-retardant resin composition having sufficient flame retardancy, heat resistance and water resistance. Things.

[0008]

The present invention is a vinyl ester having, on average, one or more phosphinic acid ester structures having a (meth) acryloyl group in an ester portion directly bonded to a phosphorus atom per molecule. The present invention is also a flame-retardant resin composition containing a radical polymerizable resin, wherein the radical polymerizable resin contains the vinyl ester, and the content of the vinyl ester is the total amount of the radical polymerizable resin. And the content of the radical polymerizable resin is 10 to 100% by weight with respect to the total amount of the flame retardant resin composition. The present invention is also a cured product obtained by curing the flame-retardant resin composition. Hereinafter, the present invention will be described in detail.

The vinyl ester of the present invention is a radically polymerizable oligomer or monomer having an average of one or more phosphinic acid ester structures having a (meth) acryloyl group in an ester portion directly bonded to a phosphorus atom per molecule.

The phosphinic acid ester structure in the vinyl ester molecule is not particularly limited as long as it has a (meth) acryloyl group in the ester portion directly bonded to a phosphorus atom. The molecular structure is preferably obtained by an addition reaction between an acid group and an epoxy group or a glycidyl group.

The number of the phosphinic acid ester structures introduced into the vinyl ester molecule is not particularly limited as long as it is one or more on average per molecule, but is preferably in the range of 1 to 5 on average per molecule. Preferably, the content of the phosphorus atom in the vinyl ester may be adjusted to a predetermined amount.

The content of phosphorus atoms in the vinyl ester is preferably 1.5 to 15.0% by weight. If the amount is less than 1.5% by weight, the flame retardancy of the cured product comprising the resin composition containing the vinyl ester may be low. If the amount exceeds 15.0% by weight, the cost of the resin composition increases. There is a risk. More preferably, 4.6
To 15.0% by weight, more preferably 5.1 to 1% by weight.
5.0% by weight.

The above (meth) acryloyl group in the molecule of the vinyl ester is at least one on average per molecule. The (meth) acryloyl group may be composed of an acryloyl group or a methacryloyl group, or may be composed of an acryloyl group and a methacryloyl group.

The number average molecular weight (M
n) is not particularly limited, but is preferably from 200 to 6000. If it is less than 200, the strength of the cured product may decrease. If it exceeds 6000, the viscosity of the resin composition may increase and the workability may decrease. More preferably, it is 350 to 2000.

The above (meth) in the above vinyl ester
The number average molecular weight (Mn) per acryloyl group is not particularly limited, but is preferably from 200 to 3000. If it is less than 200, the toughness of the cured product may decrease. If it exceeds 3000, the heat resistance and water resistance of the cured product may decrease. More preferably,
200 to 1,000.

The method for producing the vinyl ester in the present invention is not particularly limited. For example, a method in which a phosphinic acid compound is subjected to an esterification reaction with a (meth) acrylate having an epoxy group (hereinafter referred to as a production method);
A method of subjecting a phosphinic acid compound, a (meth) acrylate having an epoxy group, a polyfunctional epoxy compound, and an unsaturated monobasic acid as necessary to an esterification reaction (hereinafter referred to as a production method); A method of subjecting a basic acid and a polyfunctional epoxy compound to an esterification reaction (hereinafter referred to as a production method) and the like can be mentioned. Among these, the production method is preferred because the content of the phosphorus atom in the vinyl ester is relatively high because the introduction amount of the phosphinic acid ester structure in the molecule of the vinyl ester can be set relatively high. As a result, the cured product has sufficient flame retardancy.

The phosphinic acid compound in the above-mentioned production method and the above-mentioned phosphinic acid compound is not particularly limited as long as it has one or more active hydrogen groups. However, since physical properties such as strength and water resistance of the cured product are improved, The following general formula;

[0018]

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(Wherein, R ¹ represents a hydrocarbon group which may have a substituent; R ² represents a straight-chain or branched hydrocarbon chain). It is preferably a phosphinic acid compound. These may be used alone or in combination of two or more. Among these, R ¹ is an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 18 carbon atoms, or a carbon number having 7 to 18 carbon atoms. 2
It is preferably an alkenyl group of ~ 18. R ² is an alkylene chain having 1 to 18 carbon atoms, 3 to
It is preferably a cycloalkylene chain having 18 carbon atoms, an arylene chain having 6 to 18 carbon atoms, or an alkyl arylene chain having 7 to 18 carbon atoms.

The phosphinic acid compound represented by the above general formula is not particularly restricted but includes, for example, (2-carboxyethyl) methylphosphinic acid, (2-carboxyethyl)
Examples include ethylphosphinic acid, (2-carboxyethyl) octylphosphinic acid, (2-carboxyethyl) phenylphosphinic acid, (2-carboxymethyl) methylphosphinic acid, and (2-carboxymethyl) phenylphosphinic acid.

The (meth) acrylate having an epoxy group in the above-mentioned production method and the above-mentioned method is particularly a compound having at least one epoxy group and / or glycidyl group and at least one (meth) acryloyl group in a molecule. Without limitation, for example, glycidyl (meth) acrylate, 2-methylglycidyl (meth)
Examples thereof include acrylate, 3,4-epoxybutyl (meth) acrylate, 4,5-epoxypentyl methacrylate, and 6,7-epoxypentyl acrylate.
These may be used alone or in combination of two or more. Among these, glycidyl (meth) acrylate is preferred because it is easily available.

The polyfunctional epoxy compound in the above-mentioned production method and the above-mentioned polyfunctional epoxy compound is not particularly limited as long as it has two or more epoxy groups and / or glycidyl groups in the molecule. For example, bisphenol A type epoxy compounds, bisphenol F -Type epoxy compounds, bisphenol S-type epoxy compounds, bisphenol-type epoxy compounds such as hydrogenated bisphenol-type epoxy compounds; bisphenol-type epoxy compounds having halogen atoms such as tetrabromobisphenol A-type epoxy compounds; phenol novolak-type epoxy compounds, cresol Novolak epoxy compounds such as novolak epoxy compounds and hydrogenated novolak epoxy compounds thereof. These may be used alone or in combination of two or more. Among these, those having no halogen atom in the molecule are preferable in order that the cured product does not cause environmental pollution by dioxin during combustion.
More preferably, it is a bifunctional bisphenol-type epoxy compound because it is easily available.

The average epoxy equivalent of the polyfunctional epoxy compound is not particularly limited, but is preferably from 150 to 700. If it is less than 150, the cured product of the resin composition may have poor physical properties such as water resistance and mechanical strength. If it exceeds 700, the viscosity of the resin composition may be high and workability may be poor. More preferably, 15
0 to 500.

The unsaturated monobasic acid in the above production method and the method is not particularly limited as long as it has a (meth) acryloyl group, and examples thereof include (meth) acrylic acid. These may be used alone or in combination of two or more.

In the above production method, the ratio of the phosphinic acid compound to the (meth) acrylate having an epoxy group is not particularly limited, but the ratio is preferably 1 equivalent of the active hydrogen group of the phosphinic acid compound. It is preferable to set the ratio of the reaction raw materials so that the epoxy group and the glycidyl group of the (meth) acrylate having an epoxy group are 0.9 equivalent to 1.1 equivalent. In addition, in this specification, a reaction raw material means all the raw materials which will constitute the product by the reaction.

In the above production method, the ratio of the phosphinic acid compound, the (meth) acrylate having an epoxy group, the polyfunctional epoxy compound, and the unsaturated monobasic acid used as required is not particularly limited. An active hydrogen group of the phosphinic acid compound,
The epoxy group and / or glycidyl group of the (meth) acrylate having the epoxy group and the polyfunctional epoxy compound, relative to 1 equivalent of the total amount of the carboxyl group of the unsaturated monobasic acid used if necessary. It is preferable to set the ratio of the reaction raw materials so that the total amount of the raw materials becomes 0.9 to 1.1 equivalents. The ratio between the (meth) acrylate having an epoxy group and the polyfunctional epoxy compound is not particularly limited, but the epoxy group and / or glycidyl group of the (meth) acrylate having an epoxy group and the It is preferable to set the ratio of the functional epoxy compound to the epoxy group and / or the glycidyl group so that the equivalent ratio of the functional epoxy compound and the glycidyl group is 1: 4 to 4: 1.

In the above production method, the above unsaturated monobasic acid may be used as necessary, taking into account the viscosity of the resin composition and the physical properties such as flexibility and mechanical strength required for the cured product. However, the amount of the unsaturated monobasic acid used is not particularly limited, and may be appropriately set according to the molecular weight distribution of the vinyl ester, the crosslinking density when the resin composition is cured, and, for example, the phosphine. Based on the total equivalent weight of the active hydrogen group of the acid compound and the carboxyl group of the unsaturated monobasic acid, the equivalent of the carboxyl group of the unsaturated monobasic acid is set to be 2 to 30%. be able to.

In the above production method, the ratio of the phosphinic acid compound, the unsaturated monobasic acid, and the polyfunctional epoxy compound is not particularly limited. With respect to 1 equivalent of the total amount of carboxyl groups of the saturated monobasic acid, the total amount of epoxy groups and / or glycidyl groups of the polyfunctional epoxy compound is 0.9 to 1.1 equivalents. It is preferable to set the ratio of the reaction raw materials. Further, the ratio of the active hydrogen group of the phosphinic acid compound to the carboxyl group of the unsaturated monobasic acid is not particularly limited, but the active hydrogen group of the phosphinic acid compound and the unsaturated monobasic acid It is preferable to set the ratio of the two such that the equivalent ratio to the carboxyl group of the compound becomes 2: 1 to 1: 2. If the ratio of the active hydrogen groups contained in the phosphinic acid compound is less than 1: 2, the cured product may not have sufficient flame retardancy, and the active hydrogen groups contained in the phosphinic acid compound may be 2: 2.
If the ratio exceeds 1, the curability of the resin composition may be poor, and physical properties such as strength may be poor.

In the case where the phosphinic acid compound used in the above-mentioned production methods to has a carboxyl group, the carboxyl group is taken into consideration as well as the active hydrogen group as the reactive functional group in the phosphinic acid compound. It is preferable to set the ratio of the raw materials. In the esterification reaction in the above production method,
It is preferable to use an esterification reaction catalyst because the esterification reaction can be promoted without causing gelation.

Examples of the esterification reaction catalyst include zinc organic acids such as zinc octylate, zinc naphthenate, zinc laurate, zinc benzoate and zinc salicylate;
Amines such as triethylamine, dimethylbenzylamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium bromide, triethylbenzylammonium chloride and triethylbenzylammonium bromide; triphenylphosphine and the like And phosphonium salts such as tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, and triphenylmethylphosphonium chloride. These may be used alone or in combination of two or more. Among them, in the production method, it is preferable to use organic acid zincs, and in the production method, it is preferable to use the organic acid zincs and amines other than the organic acid zincs in combination, and in the production method, It is preferable to use amines other than zinc organic acids.

The amount of the above-mentioned esterification catalyst is not particularly limited, but when the above-mentioned organic acid zincs are used, the amount of the zinc atom is 0.00% based on the total weight of the reaction raw materials.
It is preferable to set the amount of the organic acid zinc used so as to be 5 to 3.0% by weight. When using amines other than the organic acid zincs, the amount is preferably based on the total weight of the reaction raw materials. It is preferable to set the amount of the amines and the like to be used so that the amount of the amines and the like is 0.005 to 3.0% by weight.

In the esterification reaction, if necessary, a solvent inert to the reaction may be used, and other polymerizable unsaturated monomers may coexist. The solvent is not particularly limited, and includes, for example, toluene, xylene and the like. These may be used alone or in combination of two or more. In order to sufficiently prevent gelation, esterification is performed in the presence of air; molecular oxygen such as a mixed gas of an inert gas such as nitrogen and air or oxygen; or radical polymerization inhibitors such as hydroquinone and benzoquinone. It is preferred to carry out the reaction.

The order of mixing and the method of mixing the reaction raw materials, catalysts, solvents and the like used in the above-mentioned esterification reaction are not particularly limited, and the mixing can be carried out according to the usual mixing order or method of the esterification reaction. The reaction temperature of the esterification reaction is not particularly limited. The reaction time of the esterification reaction is not particularly limited, for example, a combination of raw materials, the amount of catalyst added, the presence or absence of a solvent,
What is necessary is just to set suitably according to reaction temperature etc.

The flame-retardant resin composition of the present invention contains a radically polymerizable resin. The radically polymerizable resin in the present invention is a resin which is cured by a radical polymerization reaction and contains the above-mentioned vinyl ester. The content of the vinyl ester is from 1 to the total amount of the radical polymerizable resin.
99% by weight. If it is less than 1% by weight, the cured product will not have sufficient flame retardancy, and if it exceeds 99% by weight, the viscosity of the resin composition will be high and workability will be poor. Preferably, it is 20 to 90% by weight.

The radical polymerizable resin of the present invention may contain other radical polymerizable oligomers and other polymerizable unsaturated monomers in addition to the vinyl ester. The other radical polymerizable oligomer is not particularly limited, and examples thereof include unsaturated polyester, urethane (meth) acrylate, and polyester (meth) acrylate. These may be used alone or in combination of two or more.

The other polymerizable unsaturated monomer is not particularly limited as long as it has a radical polymerizable oligomer or a monomer having an unsaturated bond capable of undergoing a polymerization reaction with the monomer, but may have a molecular weight of less than 350. It is preferable because the viscosity of the resin can be appropriately set. For example,
Styrene, α-methylstyrene, vinyltoluene, divinylbenzene, diallyl phthalate, N-vinylpyrrolidone, diethylene glycol divinyl ether, methyl (meth) acrylate, ethyl (meth) acrylate,
Butyl (meth) acrylate, methoxyethylene glycol (meth) acrylate, 2-phenoxyethyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, ethylene glycol di (meth)
Examples include acrylate, propylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and trimethylolpropane tri (meth) acrylate. These may be used alone or in combination of two or more.

The weight ratio of the vinyl ester to the other polymerizable unsaturated monomer is from 20/80 to 99/1.
It is preferred that When the ratio of vinyl ester is more than 99/1, the viscosity of the resin composition is increased, and the workability may be reduced, and the curability may be reduced. If the proportion is small, the flame retardancy of the cured product may decrease. Since the viscosity of the resin composition becomes appropriate, and the cured product will have sufficient flame retardancy, more preferably,
30/70 to 80/20, more preferably 40/70 to 80/20.
/ 60 to 70/30.

The content of the radical polymerizable resin in the present invention is 10 to 100% by weight based on the total amount of the flame retardant resin composition. When the content is less than 10% by weight, the curability of the resin composition is poor, and the cured product loses flexibility. In order to improve the curability of the resin composition and to improve various physical properties such as the flame retardancy of the cured product, when an inorganic filler is blended in the resin composition, the total amount of the flame retardant resin composition is Preferably, the content of the radical polymerizable resin is 20 to 80% by weight, and the content of the inorganic filler is 80 to 20% by weight. When the content of the radical polymerizable resin is 2
0% by weight or the content of the inorganic filler is 8% or less.
If the content exceeds 0% by weight, the curability of the resin composition may be poor, and the cured product may lose flexibility. The content of the radical polymerizable resin may exceed 80% by weight or the content of the inorganic filler may be reduced. If the content is less than 20% by weight, various physical properties such as flame retardancy of the cured product may not be sufficient. More preferably, the content of the radical polymerizable resin is 30 to 70% by weight, and the content of the inorganic filler is 70 to 30% by weight.

The inorganic filler is not particularly limited.
For example, aluminum hydroxide, calcium carbonate, barium sulfate, alumina, metal powder, kaolin clay, talc, milled fiber, silica sand, diatomaceous earth, crystalline silica,
Examples include fused silica and glass powder. These may be used alone or in combination of two or more. Among these, it is preferable to use aluminum hydroxide as an essential component, because the moldability of the cured product is excellent and the flame retardancy is greatly improved.

The flame-retardant resin composition of the present invention may contain reinforcing fibers in order to improve various physical properties such as the strength of the cured product. The reinforcing fibers are not particularly limited, and include, for example, inorganic fibers such as glass fibers and carbon fibers; and organic fibers such as vinylon, phenol, Teflon, aramid, and polyester. These may be used alone or in combination of two or more.

The shape of the reinforcing fibers is not particularly limited, and examples thereof include cloth; mats such as chop strand mats, preformable mats, continuous strand mats, and surfacing mats; chops; rovings; Is mentioned.

A flame retardant can be added to the flame retardant resin composition of the present invention in order to improve the flame retardancy of the cured product. The flame retardant is not particularly limited, and includes, for example, those commonly used in flame retardant resin compositions.
These may be used alone or in combination of two or more. Among these, a flame retardant having no halogen atom in the molecule is preferable because the cured product does not cause environmental pollution by dioxin during combustion.

The flame retardant having no halogen atom in the molecule is not particularly restricted but includes, for example, phosphoric esters such as triphenyl phosphate, cresyl diphenyl phosphate and resorcin diphenyl phosphate; phosphorus compounds such as ammonium polyphosphate; Amino compounds such as melamine, benzoguanamine and guanidine; phosphorus-amino complex compounds such as melamine phosphate and guanidine phosphate;
Boric acid compounds such as zinc borate and aluminum borate;

The flame-retardant resin composition of the present invention is used for improving the dispersibility and curability of the resin composition and various physical properties of the cured product. Additives, solvents and the like can be blended.

The flame-retardant resin composition of the present invention has an average of one phosphinic ester structure having a (meth) acryloyl group in an ester portion directly bonded to a phosphorus atom per molecule.
A phosphorus atom covalently bonded to the resin skeleton is introduced using a vinyl ester having at least one. Thereby, the cured product comprising the flame-retardant resin composition of the present invention containing the vinyl ester, without deteriorating heat resistance, water resistance, electrical properties, mechanical properties, etc., and by curing the resin composition A sufficient and uniform flame-retardant effect can be obtained when a cured product is obtained or over time.

Therefore, the flame-retardant resin composition of the present invention has water resistance as a cured product, has physical properties such as hardness and strength, and has flame retardancy.
Further, the vinyl ester in the present invention has an effect that it can be easily produced by the esterification reaction of a phosphinic acid compound and a (meth) acrylate having an epoxy group. .

The flame-retardant resin composition of the present invention is a non-halogen resin having no halogen atom covalently bonded to a resin component such as a halogenated compound or a vinyl ester as a flame retardant in order not to cause environmental pollution and the like. It is preferred that Thereby, the flame-retardant resin composition of the present invention has a unique effect of having flame-retardancy without fear of toxicity or environmental pollution. In addition, for example, in the case where the discarded cured product is recycled without being burned,
Even if it contains a halogen atom, the effect on the environment is small, so the flame-retardant resin composition of the present invention may contain a halogen atom if necessary.

The flame retardant resin composition of the present invention may be added with a polymerization initiator to polymerize the vinyl ester to cure the resin composition, or may be polymerized by irradiation with active energy rays. In this case, a photosensitizer may be added. Further, in order to increase the polymerization rate and improve the production efficiency, a polymerization accelerator may be added. The polymerization initiator, the photosensitizer, and the polymerization accelerator may be added to the flame-retardant resin composition in advance, or may be added at the time of curing. It is preferable to set the timing of addition in consideration of stability.

The polymerization initiator is not particularly limited.
For example, ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide;
Hydroperoxides such as cumene hydroperoxide and t-butyl hydroperoxide; diacyl peroxides such as benzoyl peroxide and lauroyl peroxide; 1,1-bis (t-butylperoxy) -3,3,5 -Peroxy ketals such as trimethylcyclohexanone; peroxy esters such as t-butyl peroxybenzoate and t-butyl peroxy octoate; dialkyl peroxides such as dicumyl peroxide; dimyristyl peroxy dicarbonate and the like. Peroxides such as peroxydicarbonates are exemplified. These may be used alone or in combination of two or more.

The photosensitizer is not particularly limited, and for example, a conventional one used when polymerizing a resin composition by irradiating it with an active energy ray can be used. The polymerization accelerator is not particularly limited, for example,
Cobalt salts, tertiary amines and the like can be mentioned. These may be used alone or in combination of two or more. The amounts of the polymerization initiator, the photosensitizer, and the polymerization accelerator to be added are not particularly limited, and may be appropriately set according to, for example, the composition of the resin composition.

The flame-retardant resin composition of the present invention can be used for vehicle / machine parts, building materials, containers, electronic / electric parts, OA equipment,
It can be suitably used as a material for molded products and the like for applications requiring flame retardancy, such as precision machines, films, sheets, and pipes, and as a coating material for applications such as solder resists and resists for chemical plating in electronic materials.

The cured product of the present invention is obtained by curing the flame-retardant resin composition of the present invention. The above-mentioned curing can be carried out by a usual curing method and curing conditions, for example, heating by heating or pressurization, or irradiation with active energy rays such as ultraviolet rays, electron beams, and radiations. The cured product has sufficient flame retardancy and water resistance, and can be used for various applications. The cured product is also one of the present invention.

[0053]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Note that “parts” indicates “parts by weight”.

Preparation Example 1 A four-necked flask equipped with a thermometer, a stirrer, a gas injection pipe, and a reflux condenser was used as a reaction vessel, 214 parts of (2-carboxyethyl) phenylphosphinic acid as a phosphinic acid compound, and a reaction catalyst 2.1 parts of zinc octenoate,
And, after charging 0.1 part of hydroquinone as a polymerization inhibitor and heating to 100 ° C. while stirring in an air stream,
284 parts of glycidyl methacrylate was dropped as a (meth) acrylate having an epoxy group. Thereafter, the mixture was reacted at this temperature for 1 hour, and the acid value was 6.0 mg / KOH.
A vinyl ester (1) according to the present invention having a number average molecular weight (Mn) of 460 and a phosphorus atom content of 6.2% by weight was obtained. Further, 213 parts of a styrene monomer was added as a polymerizable unsaturated monomer to obtain a radical polymerizable resin (1).

Preparation Example 2 In a reaction vessel similar to that of Preparation Example 1, 166 (2-carboxyethyl) ethylphosphinic acid was used as a phosphinic acid compound.
Parts, 2.5 parts of triethylamine and 2.5 parts of zinc octenoate as a reaction catalyst, and 0.2 parts of hydroquinone were charged, and heated to 100 ° C. while stirring in an air stream, and then 284 parts of glycidyl methacrylate, and Araldide GY-250 as a polyfunctional epoxy compound (trade name, bisphenol type epoxy compound having an average epoxy equivalent of 185, manufactured by Ciba Specialty Chemicals)
370 parts were added dropwise. Thereafter, the reaction was carried out at this temperature for 1 hour, the acid value was 8.0 mg / KOH, and the number average molecular weight was 79.
0, a vinyl ester (2) of the present invention having a phosphorus atom content of 3.8% by weight was obtained. Further, 351 parts of a styrene monomer was added to obtain a radically polymerizable resin (2).

Preparation Example 3 In Preparation Example 1, (2) -carboxyethyl) phenylphosphinic acid was replaced with (2)
-Carboxyethyl) octylphosphinic acid in the same manner except that 250 parts were used, and the acid value was 7.0 mg / KO.
H, the number average molecular weight is 520, and the phosphorus atom content is 5.8.
The vinyl ester (3) according to the present invention was obtained in a weight%. Further, 229 parts of a styrene monomer was further blended to obtain a radically polymerizable resin (3).

Comparative Preparation Example 1 Araldide GY-25 was placed in the same reaction vessel as in Preparation Example 1.
0 (trade name) 370 parts, methacrylic acid 172 parts, triethylamine 2.3 parts, and hydroquinone 0.1 part were charged and reacted at 115 ° C. in an air stream for 6.5 hours to give an acid value of 4. 0.0mg / KOH, number average molecular weight is 54
Comparative vinyl ester (1), which was 0, was obtained. Further, 232 parts of a styrene monomer was added to obtain a comparative radical polymerizable resin (1).

Comparative Preparation Example 2 Epototote YDB-40 was placed in the same reaction vessel as in Preparation Example 1.
0 (trade name, bisphenol type epoxy compound having a bromo group having an average epoxy equivalent of 400, manufactured by Toto Kasei Co., Ltd.) 8
00 parts, 172 parts of methacrylic acid, triethylamine
8 parts and 0.15 parts of hydroquinone
The mixture was reacted at 15 ° C. in an air stream for 6.5 hours to obtain a comparative vinyl ester (2) having an acid value of 4.5 mg / KOH and a number average molecular weight of 980. Further, 417 parts of a styrene monomer was further blended to obtain a comparative radically polymerizable resin (2).

Example 100 parts of each of the radically polymerizable resins (1) to (3) of the present invention obtained in Preparation Examples 1 to 3 were added with Hygilite H-32I (trade name, aluminum hydroxide) as an inorganic filler. (Manufactured by Showa Denko KK) in an amount of 150 parts to give flame-retardant resin compositions (1) to (3) according to the present invention. Further, by adding 1.0 part of Perbutyl Z (trade name, manufactured by NOF CORPORATION) as a curing agent and mixing uniformly, the flame-retardant resin compositions (1) to (3) to which the curing agent was added were respectively added. Prepared. Next, each of the flame-retardant resin compositions to which the curing agent was added was poured into a glass plate case sandwiched with 3 mm spacers, and was heated at 100 ° C. for 30 minutes and then at 175 ° C. in a hot-air circulation drying oven. Cured for 30 minutes. After curing, the mixture was cooled to room temperature and the glass plate was removed to obtain cured products (1) to (3) according to the present invention. The obtained cured products (1) to (3) were evaluated by the following evaluation methods. The results are shown in Table 1.

[0060]Evaluation method  (1) Flame retardancy test Each of the obtained cured products was 70 mm in length and 6.5 ± in width.
A 0.5 mm strip was cut into a flame-retardant test piece.
The method for evaluating flame retardancy is described in JIS K 7201 (199).
5) "Combustion test method for polymer materials by oxygen index method"
Performed according to oxygen index. Oxygen index indicates flame retardancy
The index indicates that the material burns under the specified test conditions.
Minimum expressed as a percentage of the volume of gas mixture required to maintain
The value of oxygen concentration, the higher the value, the higher the self-extinguishing property
It is hard to burn and has high flame retardancy.

(2) Water Resistance Test The obtained cured product was immersed in hot water of 95 ° C. ± 3 ° C. for 250 hours and 500 hours. After immersion, changes in the appearance of the surface of the cured product were visually observed and evaluated.

Comparative Example Comparative resin compositions (1) and (2) were prepared in the same manner as in the Examples, using the comparative radical polymerizable resins (1) and (2) obtained in Comparative Preparation Examples 1 and 2. Was obtained respectively. Also,
To 100 parts of the comparative radical polymerizable resin (1) obtained in Comparative Preparation Example 1, 40 parts of cresyl diphenyl phosphate as an addition type phosphorus-based flame retardant was added and uniformly dissolved. 150 parts of Light H-32I (trade name) are mixed evenly and a comparative resin composition (3)
I got Using the obtained comparative resin compositions (1) to (3), comparative cured products (1) to (3) in the same manner as in the examples.
Was obtained respectively. The obtained comparative cured products (1) to (3)
Was evaluated in the same manner as in the examples. The results are shown in Table 1.

[0063]

[Table 1]

As is clear from Table 1, in Examples, the cured products (1) to (3) according to the present invention have sufficient flame retardancy because the oxygen indexes are all high. Since the surface of the cured product did not change in the water resistance test, it had excellent water resistance.

On the other hand, in the comparative example, the comparative cured product (1) had a low oxygen index and no flame retardancy because it did not contain a phosphorus atom. Comparative cured product (2)
Has a high oxygen index and flame retardancy because it contains a halogen atom, but has a risk of generating dioxin when discarded and burned, causing environmental pollution. Since the comparative cured product (3) contains phosphorus atoms due to the addition type phosphorus-based flame retardant, it has a certain degree of flame retardancy, but is inferior to the cured product according to the present invention and also inferior in water resistance. Was.

[0066]

Since the vinyl ester of the present invention and the flame-retardant resin composition using the same have the above-mentioned constitution, they have a sufficient flame retardancy as a cured product and a sufficient water resistance. are doing. The cured product of the present invention has sufficient flame retardancy and also has sufficient water resistance, so that it can be used for various applications.

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Claims (4)

[Claims] 1. A vinyl ester having, on average, one or more phosphinic acid ester structures having a (meth) acryloyl group in an ester portion directly bonded to a phosphorus atom per molecule. 2. The vinyl ester according to claim 1, wherein the vinyl ester is obtained by an esterification reaction between a phosphinic acid compound and a (meth) acrylate having an epoxy group. 3. A flame-retardant resin composition containing a radical polymerizable resin, wherein the radical polymerizable resin contains the vinyl ester according to claim 1 or 2, and the content of the vinyl ester is , Based on the total amount of the radical polymerizable resin,
The flame-retardant resin composition, wherein the content is 1 to 99% by weight, and the content of the radical polymerizable resin is 10 to 100% by weight based on the total amount of the flame-retardant resin composition. 4. A cured product obtained by curing the flame-retardant resin composition according to claim 3.