DE2003579A1 - Process for the production of polyester diacrylates - Google Patents

Description

PATENT LAWYERS ...'-. - ' DIPL-ING-CURTWALLACh DIPL.-ING. GONTHERKOCH 2003579 DR. TINO HAIBACH

8MUNCHEN2, Jan 27, 1970

Our reference: 12448 ~ Dr. Re / Re Toagos ei Chemical Industry Co., Ltd., Tokyo / Japan

Process for the production of polyester diacrylates

The invention relates to a process for the production of polyester diacrylates, the easily polymerizable oligomers with polyfunctional groups represent, from at least one dicarboxylic acid, at least one diol and acrylic acid. The term "acrylic acid" includes ordinary acrylic acid, Methacrylic acid and mixtures of acrylic acid and methacrylic acid. The term polyester diacrylate includes ordinary polyester diacrylates, Polyester-dimethacrylate and polyester-acrylate-methacrylate.

For the production of polyester diacrylates from a dicarboxylic acid, a Diol and acrylic acid, a process is known in which the starting compounds mentioned using an azeotropic dehydrating agent in the presence of an esterification catalyst and a polymerization inhibitor are esterified, whereupon the azeotropic dehydrating agent is removed after the esterification reaction has ended. For example is in Doklady Akad. Nauk., S. S. S ..R., 123, 282-284 (1958) or Vyskomolekulyarnye Soedineniya 2_, 441-446 (I960) stated that the above-mentioned polyester diacrylate or «dimethacrylate can easily be obtained by condensing a dibasic acid such as malonic acid with acrylic acid or methacrylic acid and ethylene glycol can, if toluene or benzene as a solvent (azeotropic dehydration

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agent) is used, working in the presence of an esterification catalyst such as sulfuric acid or p-toluenesulfonic acid will. In particular, it is stated there that dimethacrylate bis (ethylene glycol) phthalate by mixing 0.5 mol of phthalic anhydride, 1 mol of ethylene glycol, 1.05 mol of methacrylic acid, 6g of sulfuric acid,

250 cm of toluene and 2 g of hydroquinone and reaction of the mixture thus obtained can be obtained at a temperature of 100 to 120 ° C., the dimethacrylate bis (ethylene glycol) phthalate thus obtained being a has a specific gravity of 1.162, an acid number of 2.4, an esterification number of 552 and a viscosity of 77 cps.

Because a polyester diacrylate is an easily polymerizable oligomer with is polyfunctional groups, a polymerization inhibitor is used in the condensation reaction. The type and amount of the polymerization inhibitor, which is used in the condensation reaction, however, greatly affect the yield and purity of the desired Oligomers. The polymerization inhibitor used in the condensation reaction, which differs from the polymerization inhibitors to increase the storage stability, is therefore added, to inhibit the polymerization of the polymerizable monomer and oligomer under the conditions of the condensation reaction, the t temperature high and the composition of the reaction system complicated is. In general, a larger amount of the polymerization inhibitor added in the condensation reaction leads to an increase the amount of impurities going into the product and a reduction in the rate of the condensation reaction. The formation of polymers should therefore be prevented by using the smallest possible amount of a polymerization inhibitor.

In the above method, however, hydroquinone is used as Polymerization inhibitor used, and in relatively large

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Quantities, forgiven with de? M; ^the amount of acrylic acid. Therefore, the above process has the disadvantage that the amount of impurities in the product is high and the yield of the product is low.

According to the invention, a process for the production of polyester term high yield can be created.

Furthermore, § 11 according to the invention a method for the production of poly; ·.

n be created with high purity? as an> crosslinking agent _t molding compounds, etc., excellent leagues.

Objects and advantages of the invention appear from. the next·, existing Besehrei ^ ng.

There were investigated pslymerization inhibitors, which in the manufacture " Treatment of polyester piacrylates from dicarboxylic acids, diols and acrylic acid are suitable. It was surprisingly found that Phenothiazine in very small amounts most effective in preventing the polymerization is, so that with its help a polyester diacrylate can be obtained in high yield.

PolyesiterwDiaerylate, which from at least one dicajibpnäure, min-! at least one diol and acrylic acid are prepared have the following Structural formula.

M - GA A- G> M

■ _ ■■ '■■ ".- η

wherein η is an integer not less than 1, A is a dicarboxylic acid residue | Q is a Diplrest and M is an acrylic or methacrylic acid residue mean. The degree of polymerization of the polyester diacrylate can

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can be adjusted by changing the molar ratio between the dibasic acid and the monobasic acid.

The amount of phenothiazine added according to the invention can be 1000 ppm, based on the amount of acrylic acid, or less, in order to prevent the acrylic acid from polymerizing. It can usually be in quantities from about 100 to 500 ppm. If the amount is too small, the polymerization is only insufficiently inhibited. If the amount is greater than about 1000 ppm, the purity of the polymer obtained decreases and the polymerization properties deteriorate Purification of the polymer required in a further stage.

According to the invention, aliphatic acids are, for example, dicarboxylic acids Dicarboxylic acids such as succinic acid, adipic acid, 1,12-dodecanedicarboxylic acid etc. j aromatic dicarboxylic acids such as phthalic anhydride, isophthalic acid, Terephthalic acid, etc., maleic anhydride, etc. are used. These dicarboxylic acids can be used alone or in admixture. As diols, for example, ethylene glycol, hopylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, Tetraethylene glycol, dipropylene glycol, neopentyl glycol, xylidene glycol, 1,4 - cyclohexanedimethanol, etc. are used. These diols can alone or used in a mixture.

According to the invention, sulfuric acid, p-Toluenesulfonic acid, benzenesulf ο acid, naphthalenesulf ο acid etc. are suitable. The amount of catalyst, for example sulfuric acid, is advantageously 0.3 to 1.0% by weight, based on the concentration of the Solution.

The azeotropic dehydrating agent used in the present invention is, for example Cyclohexane, η-hexane, benzene, toluene, xylene, isopropyl ether,

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. ■ Trichlorethylene, perchlorethylene, etc. The amount of dehydrating agent is preferably chosen so that the concentration of polyester

• diacrylate after the reaction, about 20 "to 50 wt -.. Is% If the amount of the azeotropic dehydrating agent used is too small, the isolation of the desired product in the subsequent leaching step is insufficient and there is a risk that polymerization of Monomers takes place during the condensation reaction, but if the amount of the azeotropic dehydrating agent used is too large, the reaction rate becomes slow and the recovery of the desired product becomes uneconomical.

The reaction temperature depends on the type and amount of the azeotropic Drainage agent, but is usually around 70 to 120 C.

The reaction time depends on the type and amount of catalyst and however, it is preferably 10 hours Or less.

The method according to the invention comprises a one-step process and a two-step process. The one-step process is carried out as follows, for example

At least one dicarboxylic acid, at least one diol, acrylic acid, an esterification catalyst, a polymer ion inhibitor (phenothiazine and an azeotropic dehydrating agent in certain proportions filled. The mixture is obtained at the boil with stirring and heating. The vapors of the azeotropic dehydrator and water are cooled in the condenser, and the azeotropic dehydrating agent and

the water are separated from each other in the water separator. The severed azeotropic dehydrating agent is added to the reaction vessel.

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2Ü03579

returned, and the separated water is removed from the system. When the amount of water has reached the calculated value, the reaction is ended. After cooling, the reaction mixture is with a aqueous alkali solution and washed with an aqueous solution of a salt. After washing, the azeotropic dehydrating agent is off recovered from the washed reaction mixture under reduced pressure to obtain a polyester diacrylate. The thus obtained Polyester diacrylate is optionally mixed with active clay, activated carbon or the like cleaned. Even if part of the azeotropic dehydrating agent remains in the product, it does not affect the polymerization of the oligomer produced in this way when this is further processed.

The two-step process can be carried out, for example, as follows will:

At least one dicarboxylic acid, at least one diol, an esterification catalyst and an azeotropic dehydrating agent are used in certain The portions are poured into a reaction vessel equipped with a stirrer, dropping funnel, water separator and cooler. The implementation is in the carried out in the same way as in the one-step process. When the amount of water reaches the calculated value, it becomes a certain amount Acrylic acid and polymerization inhibitor (phenothiazine) through the dropping funnel added, and the reaction is continued until a certain amount of water has distilled off. Then the reaction mixture treated in the same manner as in the one-step process to obtain the product.

The conditions, working methods, etc., which apply when performing the The present method are used are known per se; But there can also be other, different conditions and working methods etc. can be applied.

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The invention is explained in more detail using the examples below.

example 1

3
A mixture of 600 g benzene, 4 cm 98% H ₃ SO ,, 59 g (0.5 mol)

Succinic acid, 150 gCl mol) triethylene glycol, 90.5 g (1.05 mol) methacrylic acid and 0.06 g of phenothiazine is poured into one with a stirrer, water separator 1 liter glass flask equipped with a cooler is filled and heated. The vapor from the azeotropic mixture of benzene and water is cooled, and the liquid is in the separator in benzene and Water separated. The water formed is removed from the system, and the benzene layer is returned to the reaction vessel.

At a reaction temperature of 77-81 C, 97% of the theoretical amount of water distill off within 5.5 hours. The ^one reaction mixture was homogeneous, and there have not been recognized polymeric substances.

The reaction mixture obtained in this way is cooled to 30 ° C. and then washed with a dilute aqueous ammonia solution containing ammonium sulfate, and then with an aqueous ammonium sulfate solution. The benzene is then removed from the washed reaction mixture by heating the mixture at a pressure of about 100 »10 mm Hg at a temperature of 40-55 ° C. for 3 hours, with 224 g of a yellow product being obtained, the main constituent of which is bis- (Contains triethylene glycol succinate dimethacrylate. The viscosity of this product is 70 cp (20 ° C.). The yield is 86.5 %.

Example 2
A mixture of 300 g benzene, 2 cm "98% H ₂ SO, 36.5 g (0.25 mol)

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Adipic acid, 56.5 g (0.375 mol) triethylene glycol, 21.5 g (0.25 mol) Methacrylic acid and 0.01 g of phenothiazine were poured into one with a stirrer,

3 500 cm flasks equipped with a water separator and cooler are filled and heated. The vapor of the azeotropic mixture of benzene and water was cooled and the condensate was dissolved in benzene and in the separator Water separated. The generated water was removed from the system and the benzene layer was returned to the reaction vessel.

At a reaction temperature of about 81-83 C, 96 % of the theoretical amount of water distilled off in 8 hours. The reaction mixture was homogeneous and no polymeric substances were found.

The reaction mixture was washed with an alkaline aqueous solution and then with an aqueous solution of a salt in the same manner as in Example 1. The benzene was removed from the washed reaction mixture by heating it at a temperature of about 40-50 ° C. under a pressure of about 100-10 mm Hg for 3 hours. 90.0 g of a yellow product were obtained, the main component of which was poly-triethylene glycol adipaO-dimethacrylate (degree of condensation η «2). The Viskosj
The yield was 89.1 %.

degree η - 2). The viscosity of this product was 200 c.p. (20 ° C).

Example 3

A mixture of 300 g benzene, 6 g p-toluenesulfonic acid, 37 g (0.25 mol) Phthalic anhydride, 4-5 g (0.5 mol) 1,4-butanediol, 43 g (0.5 mol) methacrylic acid, 3.6 g (0.05 mol) of acrylic acid and 0.02 g of phenothiazine were poured into a 500-

3
cm flask filled and then heated. The benzene layer was returned to the reaction vessel and the water was removed from the system.

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At a reaction temperature of 83-85 C, 92 % of the theoretical amount of water distilled off in 6 hours. The reaction mixture was homogeneous and: no polymeric substances could be found.

The main product was a mixture of Ms- (1,4-butanediol) phthalate dimethacrylate and bis ^ Clj ^ Biitandio ^ -phthalate-methacrylate-acrylate and bis-Clj ^ butanediol ^ phthalate diacrylate. .

Example 4
A mixture of 222.1 g of Ct, 5 mol) phthalic anhydride, 318.3 g (3.0 mol)

■ '■■■■■■ ■■■■■ - 3 ι

Ethylene glycol, 238.0 g (3.3 mol) acrylic acid, 2000 g toluene, 10 cm '"

98 % HuSO-, and 0.1? g phenothiazine was poured into a 3 liter glass flask equipped with a stirrer, water separator and condenser and then heated. The vapor from an azeotropic mixture of toluene and water was cooled and the condensate was separated into toluene and water in the water separator. The toluene layer was returned to the reaction system, while the water layer was removed from the system.

At a distillation temperature of 102-112.4 C, the calculated distilled Amount of water in 2.5 hours.

After cooling, the reaction mixture was ^{washed in the same manner 1} as in Example 1 with an alkaline aqueous solution and then with an aqueous solution of a salt. After washing, the toluene was removed from the washed reaction mixture by heating it at a pressure of 100 to 5 mm Hg at a temperature of 25 to 50 ° C. in the presence of methoxyhydroquinone for 3.5 hours. This gave 494 g of a yellow product, the main component of which was ^ bis-CDiäthylenglyko ^ -phthalat-'diacrylat »The viscous

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sity of this product was 109 cp (25 C) and the yield 95.1 % -

Example 5

A mixture of 59 g (0.5 mol) succinic acid, 106 g (1.0 mol) diethylene

3
glycol, 600 g benzene and 4 cm 98% H “SO. was filled into a 1 liter glass flask equipped with a stirrer, water separator, condenser and dropping funnel and then heated. The vaporous mixture of benzene and water was cooled in the cooler and separated into benzene and water in a water separator. The separated benzene was in the reac

tion system while the water is removed from the system P became.

At a distillation temperature of 77-81 C the calculated distilled Amount of water in 2 hours. Then a mixture of 90.5 g (1.05 mol) of methacrylic acid and 0.04 g of phenothiazine was poured through the dropping funnel added. The separated benzene was returned to the reaction system in the same manner as above, while the water was taken out removed from the system.

At a distillation temperature of 81-84 ° C, the calculated distilled Amount of water in 8 hours.

The reaction mixture treated in this way was, after cooling to 30.degree washed with an alkaline aqueous solution and then with an aqueous solution of a salt in the same manner as in Example 1. After washing, the benzene was removed from the reaction mixture by blowing it under a pressure of 100 Ms 10 mm Hg Was heated to 40-55 ° C. for 3 hours. There were 186 »6 g of a yellow Product obtained, the main component of which is bis- (diethylene glycol>. Was succinate dimethacrylate. The viscosity of this PradnÄtes

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36 ep, (20 ^° C.), and the yield 86.8%.

Comparative example _x

The procedure of Example 1 was repeated with the difference that the polymerization inhibitors given in Table 1 instead of the phenothiazine were used and that instead of sulfuric acid, the in Table 1 specified esterification catalysts were used. The received Results are given in Table 1.

Tabel!

Polymer! s ations «inhibitor

Amount (g) Esterification Catalyst Result

Hydroquinone

0.06

Hy dr oquinone monomethyl ether

N-phenyl-β-naphthylamine

^H 2 ^SO 4 2 hours after the start of the reaction, a large amount of an tin-soluble polymer gradually separated out.

2 hours after the start of the reaction, it gradually separated a large amount of insoluble polymer.

A polymer began to form 2 hours after the start of the reaction

Hydroquinone

Hydroquinone

1.0

2.0 3 hours after the start of the reaction, a large amount of polymer began to form.

A polymer began to form 3.5 hours after the start of the reaction

Hydroquinone

1.0 p-toluene 2.5 hours after the start of the sulfonic acid reaction produced a relatively large amount of an insoluble polymer deposited

0993 1719

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The results show that the phenothiazine is an excellent polymerization inhibitor in the manufacture of polyester diacrylates from at least one dicarboxylic acid, at least one diol and acrylic acid , represents.

- patent claims -

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INSPECTED

Claims (1)

Patent claims: Process for the production of polyester diacrylates by reacting at least one dicarboxylic acid, at least one diol and acrylic
or methacrylic acid in the presence of an esterification catalyst. and an azeotropic dehydrating agent, characterized in that
that the reaction is carried out in the presence of phenothiazine as a polymerization inhibitor. 2 »Method according to claim 1, characterized in that the
Phenothiazine in amounts of about 1000 ppm (based on the
Acrylic or Methacrylic acid) or less used, -, _ " 9 8 3 1/19 8 0