WO2002088151A1 - Polymerizable phosphoric ester and process for producing the same - Google Patents

Abstract

A polymerizable phosphoric ester comprising at least one compound represented by the general formula (1), (1) (wherein R1 represents hydrogen or C¿1-4? alkyl; R?2¿ represents linear or branched C¿2-6? alkylene; and n is 1 or 2) wherein the volatile solvent content is 50 ppm or lower and the content of polymerizable organic acids represented by the general formula (2) (2) (wherein R?1¿ represents hydrogen or C¿1-4? alkyl) is 1 wt.% or lower; and a process for producing the polymerizable phosphoric ester, which comprises using the polymerizable phosphoric ester as a reaction solvent to react a polyphosphoric acid with a hydroxyalkyl a-substituted acrylate.

Description

Bright fine manual polymerizable phosphoric acid ester and its manufacturing method Technical Field The present invention relates to _t BACKGROUND generally relates polymerizable phosphoric acid ester and its manufacturing method, the polymerizable phosphoric acid ester has a strong affinity for metal, and other Modification of base resins such as paints, coatings, and adhesives to improve adhesion to metals and to provide functions such as fire prevention and flame retardancy due to their copolymerizability with vinyl monomers Used as a monomer for

 For example, the following two methods are known as methods for producing such a polymerizable phosphoric ester (Polymer Processing, Vol. 39, No. 2, pp. 38-39 (199)).

 (1) Method using phosphorus oxychloride

 Hydroxyalkyl (meth) acrylate is reacted with oxychloride phosphorus to obtain a phosphoryl chloride intermediate. At this time, a volatile solvent is used for the purpose of reducing the viscosity of the reaction system and removing the reaction heat as latent heat of evaporation. The volatile solvent is limited to aprotic solvents such as methylene chloride, benzene, and toluene. Then, hydrolysis is performed to obtain a crude polymerizable phosphoric acid ester. At this time, a basic compound such as pyridine, triethylamine, sodium hydroxide or the like is usually used for the purpose of capturing by-produced hydrogen chloride. Thereafter, salts produced as by-products are removed by washing with water or solvent extraction, and then the volatile solvent and the like are distilled off under heating and reduced pressure to obtain the desired product.

 (2) Method using phosphorus pentoxide

Reaction of hydroxyalkyl (meth) acrylate with phosphorus pentoxide An acid ester intermediate is obtained. At this time, a volatile solvent is used in combination to reduce the viscosity of the reaction system and remove the heat of reaction as latent heat of evaporation, but applicable volatile solvents are limited to aprotic solvents such as benzene and toluene. Can be Next, after hydrolysis, the volatile solvent and the like are distilled off under heating and reduced pressure to obtain the desired product.

 However, these production methods require a step of hydrolyzing the P—C 1 bond or P—O—P (pyrophosphate) bond, in which case the ester bond of the target product is partially hydrolyzed. In response, (meth) acrylic acid is by-produced. Further, in the method using phosphorus oxychloride, a trace amount of chlorine remains in the polymerizable phosphoric acid ester.

 When the (meth) acrylic acid or polymerizable phosphoric acid ester containing chlorine obtained by these manufacturing methods is applied as a monomer for modifying base resin such as paints, coatings, adhesives, etc. Corrosion of the metal member in this way makes it impossible to obtain the desired protection performance.

 In addition, in these production methods, since the conditions of heating and decompression (solvent removal step) are strict in order to remove volatile solvents and by-product (meth) acrylic acid, etc., polymerization reactions are likely to occur, and the There is a danger that turbidity and solid matter will be generated, and that if the polymerization reaction proceeds further, the contents of the reactor will gel.

 On the other hand, if the conditions for the desolvation step are relaxed while suppressing abnormal polymerization, the removal of the volatile solvent will be incomplete. When such a polymerizable phosphate ester with a volatile solvent remaining is applied to paints, coatings, adhesives, etc., residual solvents such as benzene-toluene volatilize from painted articles and adhesive products, especially in living spaces, This causes air pollution in enclosed spaces such as in automobiles, and reduces safety and health. In addition, in the industrial fields dealing with foods, pharmaceuticals, and electronics materials, residual volatile solvents cause adverse effects such as contamination of products and poor quality.

Therefore, the content of the remaining volatile solvent is 50 ppm or less, preferably 10 ppm or less, and the content of corrosive impurities such as (meth) acrylic acid and chlorine is 1% by weight or less. There is a strong demand for a polymerizable phosphate ester, preferably 0.1% by weight or less. However, it is a polymerizable phosphoric acid ester containing the compound represented by the general formula (1), the volatile solvent content is 50 ppm or less, and the (meth) acrylic acid content is 1% by weight. The following have not been obtained in the past. DISCLOSURE OF THE INVENTION The present invention relates to a polymerizable organic acid which is substantially free of volatile solvents and chlorine and has a content of polymerizable organic acids such as acrylic acid and methacrylic acid by-produced below a certain level. An object of the present invention is to provide a phosphoric acid ester and a method for producing the polymerizable phosphoric acid ester which is safe and simple and industrially excellent without causing abnormal polymerization. The present inventors have conducted intensive studies to solve the above problems, and as a result, when producing a polymerizable phosphate ester, using the polymerizable phosphate ester instead of using a volatile solvent as a reaction solvent, By reacting polyphosphoric acid with hydroxyalkyl-substituted acrylate, by-products and abnormal polymerization of polymerizable organic acids can be suppressed. As a result, the content of volatile solvents is 50 ppm or less. The present inventors have found that the polymerizable phosphoric acid ester having a polymerizable organic acid content of 1% by weight or less can be produced, and have completed the present invention.

 That is, the present invention provides the following polymerizable phosphate and a method for producing the same.

 Term 1 General formula (1)

[Wherein, R ¹ represents hydrogen or an alkynole group having 1 to 4 carbon atoms. R ² represents a linear or branched alkylene group having 2 to 6 carbon atoms. n represents an integer of 1 or 2. A polymerizable phosphate ester containing at least one compound represented by the formula: wherein the boiling point under normal pressure is in the range of 50 to 200 ° C based on the weight of the polymerizable phosphate ester. The content of a certain volatile solvent is 50 Dpm or less, and the general formula (2) RO

 II

CH ₂ c OH (2)

[In the formula, R ¹ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. ]

A polymerizable phosphoric acid ester having a polymerizable organic acid content of 1% by weight or less.

Item 2—The polymerizable phosphoric acid ester according to the above item 1, wherein in the general formula (1), R ¹ is hydrogen.

Item 3 — The polymerizable phosphoric acid ester according to the above item 1, wherein in the general formula (1), R ¹ is hydrogen and R ² is an ethylene group.

 Item 4. The method for producing a polymerizable phosphoric acid ester according to the above item 1, wherein the polymerizable phosphoric acid ester is used as a reaction solvent,

 General formula (3)

R ³ o

CH ₂ = C— C— O— R ⁴ — OH (3)

[Wherein, R ³ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. R ⁴ represents a linear or branched alkylene group having 2 to 6 carbon atoms. ]

A esterification reaction of at least one kind of hydroxyalkyl-α-substituted acrylate represented by the following formula: Item 5. The method according to Item 4, wherein the polyphosphoric acid has a phosphoric acid content of 114 to 118% by weight. Item 6. A polyphosphoric acid solution obtained by dissolving polyphosphoric acid in a polymerizable phosphoric acid ester, The hydroxyalkyl mono-α-substituted acrylate represented by the general formula (3) is added little by little, or the hydroxyalkyl mono-α-substituted acrylate represented by the general formula (3) is added to the polymerizable phosphoric acid ester. 6. The production method according to the above item 4 or 5, wherein a small amount of polyphosphoric acid is added to the dissolved solution. Item 7. The concentration of unreacted polyphosphoric acid in the polyphosphoric acid solution, or the concentration of unreacted polyphosphoric acid in a solution obtained by dissolving the hydroxyalkyl_α-substituted acrylate represented by the general formula (3) in the polymerizable phosphate ester Item 7. The method according to Item 6, wherein the concentration of the hydroxyalkyl-α-substituted acrylate represented by the formula (3) does not exceed 50% by weight. Item 8. The hydroxyalkyl a-substituted acrylate represented by the general formula (3) is used in an amount of 0.2 mol to 1.2 mol based on 1 equivalent of polyphosphoric acid. The production method according to any of the above. Item 9. The method according to any one of Items 4 to 8, wherein the esterification reaction is performed in the presence of a polymerization inhibitor. Item 10. The method according to Item 9, wherein the esterification reaction is carried out while blowing an oxygen-containing gas into the reaction solution. Item 1 1. The compound represented by the general formula (3) is represented by the general formula (4)

0

CH ₂ CH—— C-O—R ⁵ — OH (4)

[Wherein, R ⁵ represents a linear or branched alkylene group having 2 to 6 carbon atoms. ] The production method according to any one of the above items 4 to 10, which is a hydroxyalkyl acrylate represented by the formula: Item 12. —The method according to Item 11, wherein the compound represented by the general formula (4) is 2-hydroxyethylacrylate. Item 13. A polymerizable phosphate ester which can be produced by the method according to any one of Items 4 to 12 above. Item 14. General formula (1)

[In the formula, R ¹ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. R ² represents a linear or branched alkylene group having 2 to 6 carbon atoms. n represents an integer of 1 or 2. ] The polymerizable phosphoric acid ester containing at least one compound represented by the formula: wherein the volatile point has a boiling point at normal pressure of 50 to 200 ° C based on the weight of the polymerizable phosphoric acid ester. The solvent content is 50 ppm or less and the general formula (2)

(2)

[In the formula, R ¹ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. ]

13. A polymerizable ester having a polymerizable organic acid content of 1% by weight or less, which can be produced by the method described in any one of the above items 4 to 12. Detailed Description of the Invention Polymerizable phosphate ester

In the polymerizable phosphoric acid ester containing the compound represented by the general formula (1), R ¹ is hydrogen or an alkyl group having 1 to 4 carbon atoms, and R ² is an ethylene group, a trimethylene group, a propylene group, A linear or branched alkylene group having 2 to 6 carbon atoms such as ethylethylene group, tetramethylene group, pentamethylene group, and hexamethylene group, wherein n is 1 or 2 and at least one compound is contained. Or a mixture. Of these compounds, particularly when importance is placed on copolymerizability with other vinyl monomers and practicality, a compound in which R ¹ is hydrogen is preferred. Further, a compound in which R ¹ is hydrogen and R ² is an ethylene group (—CH ₂ —CH ₂ —) is more preferable.

 The volatile solvent according to the present invention is a volatile organic compound having a boiling point at normal pressure of the volatile solvent in the range of 50 to 200 ° C. Specifically, hexane, heptane Aliphatic hydrocarbons such as tan, nonane, decane, benzene, toluene, xylene, ethylbenzene, 1,3,5-trimethylbenzene, 1,2,4-trimethylbenzene, 1,2,3-trimethylbenzene, p- Aromatic hydrocarbons such as benzene with dichloro, hydrocarbons containing halogen such as chloroform, trichloroethylene, tetrachloroethylene, 1,1,1-trichloroethane, 1,2-dichloroethane, 1,2-dichloropropane Ethers such as dimethoxyethane and tetrahydrofuran, esters such as ethyl acetate and butyl acetate, and methyl ethyl ketone and methyl isobutyl ketone Ketones, and n- butanol, alcohols such as hexanol may be exemplified to n-.

 The polymerizable phosphoric acid ester of the present invention has a reduced content of the above-mentioned volatile solvent, and is usually 5 Oppm or less, particularly 2 Oppm or less, and preferably 10 ppm or less. Therefore, the polymerizable phosphoric acid ester of the present invention has the conventional problems associated with the volatilization of residual solvents, such as the problem of reduced safety and health in enclosed spaces, contamination of products in the fields of foods, pharmaceuticals, and electronic materials, and quality. There is no problem such as lowering.

General formula (2) according to the present invention RO

 I I

CH ₂ = C— cC— OH ( ² )

[Wherein, R ¹ represents hydrogen or an alkyl group having 1 to 4 carbon atoms]. ]

Specific examples of the polymerizable organic acid represented by are acrylic acid, methylacrylic acid, α-ethylacrylic acid, α-η-butylacrylic acid, and the like.

 In the polymerizable phosphoric acid ester of the present invention, the content of the polymerizable organic acid is also reduced, and is usually 1% by weight or less, particularly 0.2% by weight or less, preferably 0.1% by weight or less. For this reason, the polymerizable phosphoric acid ester of the present invention has an advantage that, unlike the conventional polymerizable phosphoric acid ester, the metal member does not substantially corrode due to the polymerizable organic acid.

 Further, in the present invention, as is clear from the description of the production method described later, since no chlorine-containing raw material is used, the polymerizable phosphoric acid ester of the present invention has an extremely low chlorine content and substantially contains chlorine. Not. Therefore, there is also an advantage that corrosion of the metal member caused by chlorine does not substantially occur. Method for producing polymerizable phosphate ester of the present invention

<Polyphosphoric acid>

 In the method for producing a polymerizable phosphoric acid ester according to the present invention, polyphosphoric acid used as a raw material is not particularly limited.

 H (k + 2) P k O (3 k + 1)

 [In the formula, k is an integer of 2 or more, particularly 3 to 6. ]

The compound represented by is recommended. Industrially available polyphosphoric acid is generally called strong phosphoric acid or condensed phosphoric acid, and is a mixture of polyphosphoric acids having different values of k (condensation degree) in the above chemical formula.

Such a polyphosphoric acid is appropriately selected according to the purpose. In order to increase the composition ratio of the compound represented by the general formula (1) in the ester, a polyphosphoric acid having a phosphoric acid content of 114% by weight (the average value of k corresponds to 3) or more must be used. On the other hand, in order to emphasize workability and reduce the viscosity of the reaction system, use polyphosphoric acid with a phosphoric acid content of 118 wt% or less (the average value of k is equivalent to 6). Is recommended. Therefore, in the present invention, it is preferable to use polyphosphoric acid having an average value of k of 3 to 6 (that is, a phosphoric acid content of 114 to 118% by weight).

<Hydroxyalkyl mono! Substituted acrylate represented by general formula (3)>

 Examples of the hydroxyalkyl_α-substituted acrylate represented by the general formula (3) include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 3-hydroxypropyl acrylate. Acrylates such as 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 6-hydroxyhexyl acrylate, 5-hydroxy-3-methylpentyl acrylate, 2-hydroxyethyl methacrylate, Methacrylates such as 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, 6-hydroxyhexyl methacrylate, 5-hydroxy-3-methylpentyl methyl acrylate,And 2-hydroxyethyl-1 0; -ethyl acrylate, 2-hydroxyethyl-α-η-propyl acrylate, α-alkyl such as 2-hydroxyethyl-α_η-butyl acrylate ( Examples thereof include substituted acrylates having 2 to 4 carbon atoms, each of which may be used alone or in combination of two or more.

In particular, when emphasis is placed on copolymerizability with other vinyl monomers, acrylate esters, that is, compounds in which R ³ = Η in the general formula (3), are recommended. —Hydroxyethyl acrylate is recommended.

<Reaction solvent>

In the present invention, the polymerizable phosphoric acid ester of the present invention is used as a reaction solvent, but the first reaction solvent used is produced without using the polymerizable phosphoric acid ester of the present invention. I have no choice. Therefore, for example, when a compound represented by the general formula (3) (preferably containing a polymerization inhibitor described below) is slowly dropped into a small amount of polyphosphoric acid, a small amount of a polymerizable phosphoric acid ester is generated. When the phosphate ester is formed in this way, it functions as a reaction solvent, and thereafter, becomes a reaction system similar to the production method of the present invention.

 For example, a compound having the general formula (3) is charged into a flask having a capacity of 500 m1 with about 50 g of polyphosphoric acid, while sufficiently stirring, introducing (blowing) air (oxygen), and cooling. (Preferably containing a polymerization inhibitor described below) is slowly added dropwise. Since this reaction generates a large amount of heat, the dropwise addition is carried out at a rate effective to suppress the temperature of the reaction system to 120 ° C. or lower, preferably 100 ° C. or lower, while cooling if necessary. This produces a small amount of polymerizable phosphoric acid ester. Thereafter, according to the present invention, the reaction is continued by gradually increasing the reactant volume. In this case, the products (polymerizable phosphate) obtained in each step have almost the same composition, and can be used as a solvent for producing the polymerizable phosphate of the present invention.

 Thus, when a certain amount or more of the polymerizable phosphoric acid ester of the present invention is produced, a larger amount of the polymerizable phosphoric acid ester of the present invention can be produced by performing the production method of the present invention using this as a reaction solvent. This can be used as a reaction solvent in the production method of the present invention.

 In general, the compound represented by the general formula (3) used in producing the polymerizable phosphoric acid ester used as a reaction solvent is obtained by using the reaction solvent according to the esterification reaction of the present invention. General formula used when producing hydrophobic phosphate esters

The compound represented by the formula (3) may be different from the compound represented by the formula (3), but is usually preferably the same. By making the same, the polymerizable phosphoric ester used as a reaction solvent and the product of the production method of the present invention become the same, so that there is an advantage that there is no need to separate them.

<Esterification reaction>

In order to produce a polymerizable phosphoric acid ester containing at least one compound represented by the general formula (1) according to the present invention, the polymerizable phosphoric acid ester desired as a reaction solvent is used. There is no particular limitation other than the use of a tell.

 In the production method of the present invention, the amount of the polymerizable phosphoric acid ester used as the reaction solvent is preferably equal to or more than the weight of the polyphosphoric acid, and particularly preferably about 3 to 3 times the weight of the polyphosphoric acid. If the weight is less than the equivalent weight, it tends to be difficult to remove the heat of reaction. The following method is specifically mentioned as a production example.

 (1) A polyphosphoric acid solution obtained by dissolving polyphosphoric acid in a desired polymerizable phosphoric acid ester is obtained. Then, a hydroxyalkyl-α-substituted acrylate represented by the general formula (3) is added to the obtained polyphosphoric acid solution. Continuous or intermittent addition, esterification reaction,

 (2) A method in which the polyphosphoric acid solution described in (1) above is continuously or intermittently added to the hydroxyalkyl mono-substituted acrylate represented by the general formula (3), and an esterification reaction is performed.

 ③ The hydroxyalkyl α-substituted acrylate represented by the general formula (3) is dissolved in the desired polymerizable phosphoric acid ester, and polyphosphoric acid is continuously or intermittently added to the obtained hydroxyalkyl mono-α-substituted acrylate solution. And then subjecting it to an esterification reaction.

 In the above reaction methods (1) to (3), the hydroxyalkyl mono-substituted acrylate residue in the compound represented by the general formula (3) (from the compound of the general formula (3), the hydrogen atom at the right end of the general formula (3) is removed). The residue obtained by excluding the residue may be different from the hydroxyalkyl-α-substituted acrylate residue constituting the polymerizable phosphate used as the reaction solvent, but may be represented by the general formula (3). The compound to be used is a compound containing a hydroxyalkyl mono (¾-substituted acrylate residue) (hereinafter referred to as “general formula (3) corresponding to the reaction solvent) that constitutes the polymerizable phosphoric acid ester used as the reaction solvent. )).

 Although any of the reaction methods can be employed, in order to efficiently remove the heat of reaction generated during the esterification reaction and to suppress the polymerization reaction of the raw materials and products as much as possible, the hydroxyphosphoric acid solution is added to the polyphosphate solution. —The method of adding a substituted acrylate and conducting an esterification reaction is particularly preferred.

In the method (1), polyphosphoric acid is divided into small portions and the polymerizable phosphoric acid is divided into small portions. An operation of continuously or intermittently adding the amount of hydroxyalkyl mono-α-substituted acrylate necessary for completing the esterification reaction to the amount of polyphosphoric acid added in portions to the steal. May be repeated.

 Therefore, in the present invention, a hydroxyalkyl mono-substituted acrylate represented by the general formula (3) is added little by little to a polyphosphoric acid solution obtained by dissolving polyphosphoric acid in a polymerizable phosphoric acid ester, or The esterification reaction can be carried out by adding the polyphosphoric acid little by little to a solution obtained by dissolving the hydroxyalkyl monosubstituted acrylate represented by the general formula (3) in the polymerizable phosphate ester. The addition rate when the hydroxyalkyl mono-a-substituted acrylate represented by the general formula (3) is added little by little can be appropriately selected. However, since this reaction is an exothermic reaction, if the addition rate is excessively increased, the amount of generated heat becomes too large, and an undesirable polymerization reaction tends to start. Therefore, in general, it is preferable to set the addition rate so that the temperature of the reaction system can be adjusted to 120 ° C, preferably 40 to 100 ° C. In the above reaction methods (1) and (2), the concentration of the polyphosphoric acid solution is not particularly limited, but is usually adjusted so that the concentration of unreacted polyphosphoric acid in the polyphosphoric acid solution does not exceed 50% by weight. Is preferred. In other words, it is preferable to adjust the amount of polyphosphoric acid dissolved in 100 parts by weight of the polymerizable phosphoric acid ester as a solvent so as not to exceed 100 parts by weight.

 Although the reaction apparatus is not particularly limited, for example, it can be manufactured using a stirred tank type reactor. In this case, the total volume of polymerizable phosphate ester and polyphosphoric acid added in advance is appropriately determined according to the stirring capacity and cooling capacity of the reactor used, but 30% of the capacity of the reactor is used. It is preferable from the viewpoint of the stirring efficiency and the cooling efficiency to be about the same, and it is preferable to use the polyphosphoric acid in an amount of 50% by weight or less based on the polymerizable phosphoric acid ester. That is, it is preferable that the amount of the polyphosphoric acid dissolved in 100 parts by weight of the polymerizable phosphoric acid ester as the solvent is adjusted so as not to exceed 50 parts by weight.

 In the reaction method (3), the concentration of the solution of the compound represented by the general formula (3) is not particularly limited, but is preferably 50% by weight or less.

On the other hand, polyphosphoric acid and a hydroxyalkyl-Q! -Substituted compound represented by the general formula (3) Since the reaction with acrylate is an exothermic reaction, for example, it is preferable to add the hydroxyalkyl-Q! -Substituted acrylate represented by the general formula (3) little by little. The amount of the hydroxyalkyl-a-substituted acrylate represented by the general formula (3) per 1 equivalent of polyboric acid is not particularly limited, but may be from 0.2 mol to 1.2 mol, particularly from 0 mol. 5 mol to 1.0 mol is recommended. One equivalent of polyphosphoric acid indicates the amount of polyphosphoric acid containing several phosphorus atoms of Apogadro. From the phosphoric acid content C [%] of polyphosphoric acid, the calculation formula is: (molecular weight of phosphoric acid) X 100 / C = 9, 800 / C. If the amount of the hydroxyalkyl monosubstituted acrylate used is less than 0.2 mol, the amount of unreacted polyphosphoric acid tends to increase, and if it exceeds 1.2 mol, the amount of unreacted hydroxyalkyl monoacrylate decreases. The substitution acrylate tends to increase.

 Further, the desired polymerizable phosphoric acid ester and the hydroxyalkyl mono-a-substituted acrylate represented by the general formula (3) as a raw material have a polymerizable vinyl bond, so that in the above reaction, It is preferable to use an inhibitor and control the reaction temperature within the temperature range described below.

 Examples of the polymerization inhibitor include, but are not particularly limited to, quinone having a hydrid, 2,5-di-tert-butylhydroquinone, p-tert-butyl diethanol, p-methoxyphenol, — Phenolic compounds such as tert-butyl-4-methoxyphenol and 2,6-ditert-butyl-4-methylphenol; phenothiazine; methylene blue; It is recommended that these polymerization inhibitors be used in an amount of usually 0.0001 to 1% by weight, preferably 0.01 to 0.5% by weight, based on the resulting polymerizable phosphate ester. You. Further, the polymerization inhibitor is preferably present in both the polymerizable ester phosphate previously added as a solvent and the hydroxyalkyl-1-a-substituted acrylate added later.

Thus, when a polymerization inhibitor is used for both a polymerizable phosphate ester and a hydroxyalkyl_a-substituted acrylate as a solvent, the amount of the polymerization inhibitor used is represented by the general formula (3). Hydroxyalkyl-usually in the range of 0001% to 2% by weight, preferably 0.01% to 1% by weight, based on monosubstituted acrylate. It is recommended that they be used in boxes.

 Since the polymerization inhibitor used in the esterification reaction is not substantially crushed, it remains in the polymerizable phosphoric acid ester of the present invention to be obtained. Work as

 Furthermore, it is particularly preferable to blow an oxygen-containing gas such as air, an air / nitrogen mixture, or an oxygen / nitrogen mixture into the reaction solution, if necessary, together with the addition of the polymerization inhibitor. It is preferable that the oxygen-containing gas be removed of water through calcium chloride, silica gel, or the like, or by an air compressor or the like.

 The blowing rate of the oxygen-containing gas can be selected from a wide range. For example, when air is used, 0.1 to: L per kg of the final target product (including the polymerizable phosphate used as a reaction solvent) The speed is preferably about 0 m1 Zmin, particularly about 0.5 to 5 ml Zmin. The blowing of the oxygen-containing gas may be performed throughout the entire reaction time of the esterification reaction, or may be performed during a part of the reaction time.

 Usually, the reaction temperature is preferably in the range of room temperature to 120 ° C., more preferably in the range of 401 to 100 :. When the reaction temperature is lower than room temperature, the viscosity of the reaction solution tends to be high and stirring tends to be difficult, and when the reaction temperature is higher than 120 ° C, it is difficult to suppress the polymerization. Tend to be.

 The pressure during the reaction is not particularly limited, but is preferably normal pressure or pressurized (for example, about 0.10 to 0.15 MPa). When the reaction pressure is reduced, polymerization tends to easily occur due to lack of oxygen or the like. In addition, the reaction time depends on the type of the reaction apparatus, the type of raw materials, the amount charged, the reaction temperature, and the like, and can be appropriately set so that the above-mentioned esterification reaction is completed. The reaction type may be either a batch type or a continuous type.

The reaction mixture thus obtained is the polymerizable phosphate ester of the present invention. The polymerizable phosphate ester has a volatile solvent content of 5 ppm or less and is represented by the general formula (2). Content of the polymerizable organic acid is 1% by weight or less. The reaction mixture thus obtained, that is, the polymerizable phosphoric ester of the present invention can be used as it is for the following applications. The polymerizable phosphoric acid ester of the present invention thus obtained can be used in the same applications as conventionally known polymerizable phosphoric acid esters. For example, such a polymerizable phosphate ester has a polymerizable vinyl bond, has a good copolymerizability with other vinyl monomers, and has a strong affinity with a metal, so that it can be used for paints, coating agents, It can be used as a monomer for modifying base resins such as adhesives.

 In particular, it is useful as a monomer for UV- or electron beam-curable paints, coatings, adhesives, etc., depending on the application, 2-hydroxyethyl acrylate, 2-ethylhexyl acrylate, 4 It is mixed and used with commercially available vinyl monomers such as butanediol diacrylate, 1,6-hexanedioldiol diacrylate, diethylene glycol diacrylate, and neopentyl glycol diacrylate, and is used in combination with benzophenones, thioxanthones, Commercially available photopolymerization initiators such as polyhydroxyalkylphenones and acylphosphinoxides are added in an amount of 1% by weight to 5% by weight to be photocured. It has excellent corrosion protection because corrosive impurities are reduced to 1% by weight or less, has flame retardancy, and has virtually no environmental pollution due to residual solvents. Or, it is a material that is particularly suitable for coating and bonding applications such as kitchen metal articles, automotive components, and electronic components.

 Further, the polymerizable phosphoric acid ester and its polymer can be used as a chelating agent, an antistatic agent, an anti-fogging agent, a flame retardant, and an anti-oxidant. Examples Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.

 The contents of (meth) acrylic acid, unreacted hydroxyalkyl-α-substituted acrylate and volatile components in the obtained polymerizable phosphate were separated and quantified by head-gas chromatography. .

 The specific gravity of the polymerizable phosphoric acid ester was measured according to JIS K 061-4, and the viscosity was measured according to JIS K 7171-1.

Example 1

5 L tank-type reaction equipped with rotary stirrer, air blowing tube, gas vent, and thermometer In a vessel, 2000 g of the desired polymerizable phosphoric acid ester (containing 0.4% by weight of p-methoxyphenol (polymerization inhibitor)) as a reaction solvent, polyphosphoric acid (116% by weight of strong phosphoric acid, 1000 g (11.8 equivalents) was prepared, and the resulting mixture was stirred at 60 ° C for 0.5 hours while blowing air at 5 Oml / min from an air compressor to remove the polyphosphoric acid solution. Obtained.

 Thereafter, 9.5 g of p-methoxyphenol was dissolved in 1374 g (11.8 mol) of 2-hydroxyethyl acrylate, a compound of the general formula (3) corresponding to the above reaction solvent, and the resulting solution was dissolved. Was added dropwise to the above polyphosphoric acid solution at 60 ° C. over 2 hours, and aged at 60 ° C. for 1 hour.

 As a result, viscosity (40 ° C) 8.4P a · s, specific gravity d (40 ° C / 4 ° C) 1.437, acrylic acid content 0.02% by weight, unreacted 2-hydroxyethyl As a result, 4374 g of a pale yellow transparent liquid having an acrylate content of 0.3% by weight and a volatile solvent content of 10 ppm or less was obtained. The pale yellow transparent liquid contained 0.4% by weight of p-methoxyphenol as a polymerization inhibitor.

It was confirmed from the analysis results of IR and ¹³ C-NMR that the above pale yellow liquid was a phosphoric acid ester of 2-hydroxyethyl acrylate, that is, a polymerizable phosphoric acid ester according to the present invention. . That is, in the above reaction product, the absorption of 3430 cm- ¹ (〇—H bond) observed in the raw material (2-hydroxyethyl acrylate) in the IR analysis disappeared, and the amount of the reaction product was 995 to 1020 cm- ^1. A new absorption (P—O—C bond) appears at ¹³ ppm—64 ppm (CH2O), 68 ppm (CH2O), 127 ppm (= CH), 133 ppm in ¹³ C—NMR (D ₂₀ ). (CH ₂ =), showing a signal of 168 ppm (CO).

The polymerizable phosphoric acid ester used as the reaction solvent was prepared as follows. 2-hydroxyhexyl acrylate in which 50 g (0.59 equivalents) of the same polyphosphoric acid as above was charged into a 500 ml tank reactor of the same type as above, and 0.475 g of p-methoxyphenol was dissolved 68. 7 g (0.59 mol) was allowed to react dropwise with stirring while blowing air at 5 ml / min to prepare a reaction solvent to be used first. During the dropwise addition, a large amount of heat was generated. Thus, the mixture was added dropwise over 6 hours while maintaining the temperature of the reaction system at 60. After the addition, the mixture was further aged at 60 ° C. for 1 hour. Based on the initial reaction solvent thus obtained, the reaction was continued according to the present invention, with the volume of the reactants being increased stepwise. That is, 119 g (1.4 equivalents) of the same polyphosphoric acid as described above was charged into a reactor containing 119.2 g of the product obtained above, and air was supplied to the resulting mixture at 5 m1 Zmin. After stirring at 60 ° C for 0.5 hour while blowing, 163.5 g (1.4mo1) of 2-hydroxyethyl acrylate in which 1.13 g of p-methoxyphenol was dissolved was added under stirring. The solution was dropped at 60 ° C. for 2 hours, and aged at 60 ° C. for 1 hour.

 Thereafter, 380 g of the product in the reactor was transferred to a 2 L tank-type reactor of the same type, and the same polyphosphoric acid as above (20 Og (2.36 equivalents)) was charged, and air was added to the resulting mixture with 20 ml of air. After stirring at 60 ° 〇 for 0.5 hour while blowing with, 274.8 g (2.36 mol) of 2-hydroxyethyl acrylate in which 1.9 g of p-methoxyphenol was dissolved was added. The mixture was added dropwise with stirring at 60 over 2 hours and further aged at 60 C for 1 hour.

Then, 855.7 g of the product was charged with 500 g (5.9 equivalents) of the same polyphosphoric acid as described above, and the resulting mixture was blown with 20 ml of Zm in for 0.5 hour at 60 ^nC. After stirring, 687 g (5.9 mol) of 2-hydroxyethyl acrylate dissolved in 4.75 g of p-methoxyphenol was added dropwise with stirring at 60 ° C over 2 hours. Aged at 60 ° C for 1 hour.

 Thus, 2048 g of a polymerizable phosphoric ester used as a reaction solvent in Example 1 (containing 0.4% by weight of p-methoxyphenol as a polymerization inhibitor) was obtained.

Example 2

 In the same reactor as in Example 1, 2,000 g of the desired polymerizable phosphoric acid ester (containing 0.1% by weight of hydroquinone) and 1000 g of polyphosphoric acid (115% by weight of polyphosphoric acid, commercially available reagent) were used as reaction solvents. .7 equivalents), and the mixture was stirred at 70 for 0.5 hours while blowing air at 50 ml / min from an air compressor to obtain a polyphosphoric acid solution.

Then, 2.4 g of hydroquinone was dissolved in 1353 g (9.4 mol) of 2-hydroxypropyl methacrylate, a compound of the general formula (3) corresponding to the above reaction solvent, and the resulting solution was dissolved in 70% At 2 ° C over 2 hours, The obtained reaction mixture was further aged at 70 ° C. for 5 hours.

 As a result, viscosity (40 ° C) 5.8 Pas, specific gravity d (40. <3/4) 1.39

0, 0.04% by weight of methacrylic acid, 1.7% by weight of unreacted 2-hydroxypropyl methacrylate, 4352 g of a yellow transparent liquid having a volatile solvent content of 10 ppm or less . The pale yellow transparent liquid contained 0.1% by weight of hydroquinone as a polymerization inhibitor.

It was confirmed from the results of IR and ¹³ C-NMR that the liquid was a phosphoric acid ester of 2-hydroxypropyl methacrylate, that is, the polymerizable phosphoric acid ester according to the present invention. That is, in the above reaction product, the absorption at 3430 cm- ¹ (0-H bond) observed in the raw material in the IR analysis disappeared, and 1024 to 103

A new absorption (P—O—C bond) appears at 6 cm— ¹ and, according to ¹³ C—NMR (D ₂ 17), 17 ppm (CH ₃ ), 18 ppm (CH ₃ ), 70 ppm p pm (CH〇), 7

5 p pm (CH2O), 124 p pm (CH ₂ =), 137 p pm (= C), 16

A signal of 8 ppm (CO) was shown.

 The polymerizable phosphoric ester used as the reaction solvent was prepared in the same manner as in Example 1 except that 2-hydroxypropyl methacrylate was used instead of 2-hydroxyethyl acrylate.

Example 3

 After adding 2000 g of the desired polymerizable phosphoric acid ester (containing 0.4% by weight of p-methoxyphenol) to the same reactor as in Example 1, the general formula (3) corresponding to the above reaction solvent was added. 1031 g of 2-hydroxyethyl acrylate, a compound of the formula

(8.9 mol), 8.lg of p-methoxyphenol, and stirring at 60 ° C for 0.5 hour while blowing 50 ml of air from the air compressor into the resulting mixture. A 2-hydroxyethyl acrylate solution was prepared.

Then, 1000 g (11.8 equivalents) of polyphosphoric acid (116% by weight strong phosphoric acid, manufactured by Rasa Kogyo Co., Ltd.) was added dropwise at 60 ° C. to the 2-hydroxyethyl acrylate solution over 4 hours. The obtained reaction mixture was aged at 60 ° C. for 1 hour. As a result, the acrylic acid content was 0.8% by weight, viscosity (40 ° C) 9.6 Pas, specific gravity d (40 ° C / 4 ° C) 1.500, and unreacted 2-hydroxy Tilacrylate content 0. There was obtained 420 g of a pale yellow transparent liquid having a volatile solvent content of 2% by weight and a volatile solvent content of 10 ppm or less. The pale yellow transparent liquid contained 0.4% by weight of p-methoxyphenol as a polymerization inhibitor.

The IR and ¹³ C-NMR analysis results of the above pale yellow liquid are practically the same as those in Example 1, and the phosphoric acid ester of 2-hydroxyethyl acrylate, ie, the present invention, It was confirmed that this was a polymerizable phosphoric acid ester.

 The polymerizable phosphoric acid ester used as the reaction solvent was produced in the same manner as in Example 1.

Comparative Example 1

 The same reaction as in Example 1 was carried out except that a volatile solvent was used instead of the polymerizable phosphate ester (reaction solvent) previously added.

 More specifically, in a 5 L tank-type reactor equipped with a rotary stirrer, air blowing tube, reflux cooling device, and thermometer, 200 g of toluene as a reaction solvent and 116 wt% of strong phosphoric acid as polyphosphoric acid 100 g (11.8 equivalents) was added, and the resulting mixture was stirred at 60 ° C while blowing air through an air compressor at 5 Oml Zmin, to disperse the polyphosphoric acid. I got

 Next, 137.4 g (11.8 mol) of 2-hydroxyethyl acrylate in which 9.5 g of p-methoxyphenol was dissolved was added to the above polyphosphoric acid dispersion at 60 ° C for 2 hours. It was added dropwise over time, and the resulting reaction mixture was aged at 60 for 1 hour.

 Thereafter, the inside of the reactor was depressurized while continuing air blowing, and the solvent was recovered. Further, toluene was distilled off at 60 ° C. and 667 Pa for 1 hour. As a result, the product was a cloudy paste-like liquid in which a large amount of insoluble and infusible polymer precipitated, and the content of the volatile organic solvent (toluene) was as high as 2000 ppm. INDUSTRIAL APPLICABILITY The method for producing a polymerizable phosphate according to the present invention is substantially free of harmful volatile organic compounds and chlorine, and becomes cloudy or gel-like due to abnormal polymerization during the production process. It is possible to reduce corrosive impurities as much as possible without causing generation of rust.

Claims

 Range of claim General formula (1)

[In the formula, R ¹ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. R ² represents a linear or branched alkylene group having 2 to 6 carbon atoms. η represents an integer of 1 or 2. ] The polymerizable phosphoric acid ester containing at least one compound represented by the formula: wherein the volatile point has a boiling point at normal pressure of 50 to 200 ° C based on the weight of the polymerizable phosphoric acid ester. The content of the solvent is 5 Oppm or less, and the general formula (2)

R 0

 II

CH ₂ ^{= C- c} C-OH (2)

[In the formula, R ¹ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. ]

 A polymerizable phosphoric acid ester having a polymerizable organic acid content of 1% by weight or less.

2. The polymerizable phosphate according to claim ¹ , wherein in the general formula (1), R ¹ is hydrogen.

3. The polymerizable phosphate according to claim ¹ , wherein R ¹ is hydrogen and R ² is an ethylene group in the general formula (1).

4. The method for producing a polymerizable phosphate according to claim 1, wherein the polymerizable phosphate is used as a reaction solvent,

General formula (3)

R 3

 0

CH ₂ = C— C— 0— _R 4— _0H (3)

[Wherein, R ³ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. R ⁴ represents a linear or branched alkylene group having 2 to 6 carbon atoms. ]

2. The method for producing a polymerizable phosphoric acid ester according to claim 1, wherein the esterification reaction is performed with at least one kind of hydroxyalkyl-<<-substituted acrylate represented by the following formula:

5. The method according to claim 4, wherein the polyphosphoric acid has a phosphoric acid content of 114 to 118% by weight.

6. To a polyphosphoric acid solution obtained by dissolving polyphosphoric acid in a polymerizable phosphoric acid ester, add the hydroxyalkyl _α-substituted acrylate represented by the general formula (3) little by little, or 5. The production method according to claim 4, wherein polyphosphoric acid is added little by little to a solution obtained by dissolving the hydroxyalkyl-α-substituted acrylate represented by the general formula (3).

7. The concentration of unreacted polyphosphoric acid in the polyphosphoric acid solution or the general formula (3) in a solution obtained by dissolving a hydroxyalkyl mono-α-substituted acrylate represented by the general formula (3) in a polymerizable phosphate ester. 7. The process according to claim 6, wherein the concentration of the hydroxyalkyl mono-substituted acrylate represented by 3) does not exceed 50% by weight.

8. The production according to claim 4, wherein the hydroxyalkyl mono-α-substituted acrylate represented by the general formula (3) is used in an amount of 0.2 mol to 1.2 mol per 1 equivalent of polyphosphoric acid. Method.

9. The production method according to claim 4, wherein the esterification reaction oen is performed in the presence of a polymerization inhibitor.

10. The production method according to claim 9, wherein the esterification reaction is performed while blowing an oxygen-containing gas into the reaction solution.

11. The compound represented by the general formula (3) is represented by the general formula (4)

0

 II,

CH = CH— G— O— R ⁵ — OH (4)

[Wherein, R ⁵ represents a linear or branched alkylene group having 2 to 6 carbon atoms. 5. The method according to claim 4, which is a hydroxyalkyl acrylate represented by the following formula:

12. The production method according to claim 11, wherein the compound represented by the general formula (4) is 2-hydroxyethyl acrylate.

13. A polymerizable phosphoric ester which can be produced by the method according to claim 4.

4 General formula (1)

R ¹

 I 0 ί 【

O— R ² — 0 P (OHJ ₃ _ _n (1)

[In the formula, R ¹ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. R ² represents a linear or branched alkylene group having 2 to 6 carbon atoms. n represents an integer of 1 or 2. ] The polymerizable phosphoric acid ester containing at least one compound represented by the formula: wherein the volatile point has a boiling point at normal pressure of 50 to 200 ° C based on the weight of the polymerizable phosphoric acid ester. The solvent content is 50 ppm or less, and the general formula (2)

R O

II

CH2 ^{= C} — C— OH (2)

[In the formula, R ¹ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. ]

A polymerizable phosphoric acid ester having a polymerizable organic acid content of 1% by weight or less, which can be produced by the method according to claim 4.