KR20030061357A - Process for the preparation of esters of (meth)acrylic acid - Google Patents

Abstract

The present invention relates to a process for preparing esters of (meth) acrylic acid by (trans) esterification of monohydric or polyhydric alcohols with (meth) acrylic acid or ester derivatives thereof in the presence of an acidic (trans) esterification catalyst,

Reacting the remaining acid groups with one or more component (s) after formation of an ester of (meth) acrylic acid, wherein at least one component forms an ester compound having no β-hydroxy group at least with the catalyst or an amide compound The component which forms and preferably reacts with the acidic (trans) esterification catalyst is characterized in that it is selected from the group consisting of an oxetane component or derivative, an ortho-ester component, an alcohol component or a specific mixture thereof.

Description

Production method of ester of (meth) acrylic acid {PROCESS FOR THE PREPARATION OF ESTERS OF (METH) ACRYLIC ACID}

The present invention relates to a process for the preparation of esters of (meth) acrylic acid in the presence of an acidic (trans) esterification catalyst and to a neutralization method of the acidic (trans) esterification catalyst. The (trans) esterification means both esterification as well as trans-esterification.

DE-2838691 (UCB) discloses the production of acrylic polyesters by reacting acrylic acid with hydroxy-functional polyesters and removing the remaining acid (s) by an aqueous base neutralization step.

The method described in DE-2838691 has the disadvantage that a complex, time-consuming washing step involving another separation step is used to remove the acidic catalyst and residual acrylic acid. Moreover, the cleaning step produces chemical waste, which is environmentally unfriendly.

It is an object of the present invention to overcome the above drawbacks, a method of preparing esters of (meth) acrylic acid in the presence of an acidic (trans) esterification catalyst, in particular the complex cleaning necessary to remove free acid groups of acidic catalysts. It provides a way to avoid the steps.

It is also an object of the present invention to provide a process for neutralizing an acidic (trans) esterification catalyst in a reaction mixture comprising an ester compound without the necessary washing step.

Surprisingly, at least one of the above objects is a process for preparing esters of (meth) acrylic acid by (trans) esterifying monohydric or polyhydric alcohols with (meth) acrylic acid or ester derivatives thereof in the presence of an acidic (trans) esterification catalyst. Obtained by reacting one or more component (s) with the remaining acid groups after formation of an ester of (meth) acrylic acid, the at least one component being at least an acidic catalyst having no β-hydroxy group Or form an amide compound.

The term "monohydric or polyhydric alcohols" refers to all forms of monohydric alcohols and polyhydric alcohols, and also to hydroxy-functional polymers, for example those comprising hydroxy-functional polyesters. This will be explained further in the following.

For comparison, an ester compound having a β-hydroxy group may be represented by the following Chemical Formula 1:

In the above, (meth) acrylic acid means a compound according to Formula 2:

(In Formula 2, R ¹ , R ² , R ³ are the same or different and are selected from hydrogen, C1-C12 alkyl or alkaryl, C6-C12 aryl or arylalkyl or halogen, or -CH ₂ -X, Wherein X can be selected from halogen, hydroxy or alkoxy having 1-6 carbon atoms)

For example, when R ¹ , R ^2, and R ³ are all hydrogen, the compound is acrylic acid, when R ¹ and R ² are hydrogen, and R ³ is methyl, the compound is crotonic acid, and R ² and R ^{When 3} is hydrogen and R ¹ is methyl, the compound is methacrylic acid, when R ¹ and R ² are hydrogen and R ³ is phenyl, the compound is cinnamic acid.

According to a further embodiment of the present invention, one or more of the above objects can be obtained by a process for neutralizing an acidic (trans) esterification catalyst in a reaction mixture comprising an ester compound, the process comprising an acidic catalyst Reacting one or more component (s) with the mixture, wherein at least one component forms an ester compound having no β-hydroxy group or at least an amide compound with at least the acidic (trans) esterification catalyst.

In the process of the present invention, an ester of (meth) acrylic acid having excellent hydrolytic stability is obtained, and a resin containing the ester of (meth) acrylic acid is stable to hydrolysis, and can be obtained that does not become cloudy over time. Has additional advantages.

EP 0 54 105 A1 (Vianova) also discloses the use of epoxides to neutralize the free acrylic acid remaining after the synthesis of acrylic polyesters. The neutralized acrylic polyester does not show good hydrolysis resistance.

EP 0 933 353 A1 (BASF) also discloses the removal of free acid and alcohol by washing the catalyst and adding a water soluble coagulant to the (poly) esteracrylate reaction mixture. Disadvantages of this method are that the cleaning is essential and generates chemical waste, which is time consuming and therefore more expensive.

Improvements made by the inventors include (meth) acrylic acid esters by (trans) esterifying (meth) acrylic acid or its ester derivatives with monohydric or polyhydric alcohols in the presence of an acidic (trans) esterification catalyst. It can be used in the production method of.

An ester of (meth) acrylic acid can be defined as a (meth) acrylate functional compound from which the hydroxyl functional compound (i) is derived from the reaction of (meth) acrylic acid or its ester derivative (ii), wherein the hydroxyl functional compound May have a mono-, di- or multiple functional group and has R group as the main chain. R is an aliphatic, cycloaliphatic or aromatic chain, (poly) ether, (poly) ester, for example (poly) caprolactone, (poly) alkyd, (poly) urethane, (poly) amine, (poly) amide , (Poly) carbonates, (poly) olefins, (poly) siloxanes, (poly) acrylates, halogens (eg fluorine), melamine-derivatives, copolymers thereof, and the like.

(Poly) alkyds are considered to be in the form of polyesters. Alkyd (meth) acrylates include alkyd main chains derived from alkyd resins and (meth) acrylate reactive end groups. Alkyd resins or alkyds are polyesters having pendant ester groups extending from the main polymer chain of the ester bond. The pendant groups of the alkyds can be introduced by adding monofunctional carboxylic acids (monoacids) with the appropriate components used to make the polyesters.

For simplicity, "polyester" is also used to refer to both (poly) esters and (poly) alkyds. The term "(meth) acrylate" is used to refer to methacrylates and acrylates.

Esters of (meth) acrylic acid can be prepared by (trans) esterifying monohydric or polyhydric alcohols (i) and (meth) acrylic acid or ester derivatives thereof (ii) in the presence of an acidic (trans) esterification catalyst. .

(Meth) acrylic acid reacts with hydroxyl groups bonded to the R-chain, oligomer or polymer in the formation of (meth) acrylate esters and water molecules. The equilibrium reaction is activated with acid. By removing the reaction water and using excess (meth) acrylic acid, the equilibrium can be transferred to the reaction product. Usually, organic solvents are used to help azeotropically remove the reaction water. This can be done by vacuum distillation of the solvent. Continuously the desired ester compound is obtained with high yield.

The synthesis process can be carried out in one step, two steps or more. In a one step process, all of the alcohol compound (i), (meth) acrylic acid or its ester derivative (ii) and the catalyst are placed in the reactor in air. In a two stage process, alcohol component (i) is prepared in the first stage, and the alcohol is further (meth) acrylated in the second stage. Details of the one-step and two-step processes will be described below for the preparation of the polyester (meth) acrylates.

In the (trans) esterification process, a moderately low or high Mw alcohol (i) can be used. According to one preferred embodiment, low Mw alcohols (i) having up to 8 carbon atoms are used because they have the advantage of low viscosity. The Mw of the low Mw alcohol is preferably less than about 240, more preferably less than about 200.

In additional embodiments, alcohol (i) having 9 or more carbon atoms is used, but less than 300 Mw is beneficial because of its low viscosity. According to another embodiment, alcohol (i) having a Mw of at least about 300 and less than about 10,000 is preferred, alcohols having a Mw of at least about 400 are more preferred, and alcohols having a Mw of at least about 500. The alcohol has a high vapor pressure and therefore low toxicity.

As catalysts, organic and inorganic acid catalysts are effective. The catalyst may also be incorporated or have functional groups incorporated into polymers or preferably esters of (meth) acrylic acid, such as sulfonic acid functional polymers, phosphoric acid functional polymers and the like. Preferably, the catalyst is a strong acid (having a pKa value of less than about 2, measured at 25 ° C. in water). As the organic acid catalyst, alkyl sulfonic acid such as methane sulfonic acid, aryl sulfonic acid such as p-toluene sulfonic acid, benzene sulfonic acid, styrene sulfonic acid and the like can be provided. As the inorganic catalyst, sulfuric acid, mono-ester of sulfuric acid, phosphoric acid, mono-ester of phosphoric acid and the like can be provided. As a catalyst, for example, p-toluene sulfonic acid is preferred because it shows a high effect at relatively low temperatures at which the (meth) acrylation step is carried out.

The concentration of the catalyst in the reaction mixture is usually at 0.1-10 wt.%, Preferably 0.2-7 wt.%, More preferably 0.5-5 wt.% And even more preferably 0.7-3 wt.% (Based on the total weight). If a polymerizable catalyst is used, it is used in the range of 0.1-50 wt%, preferably in the range of 0.5-40 wt%, more preferably in the range of 1.0-30 wt%.

After esterification (optional) and (meth) acrylation, some free acid groups remain in the reaction mixture.

In the (meth) acrylation step during the synthesis of an acid remaining in the ester of (meth) acrylic acid, for example residual (meth) acrylic acid and, if available, an acid of the remaining catalyst (e.g. Quantification of (if used as a catalyst) can be quantified by the acid value of the ester of (meth) acrylic acid (additionally defined as a resin). The acid value of the resin is a unit of measure of the free acid content of the resin, expressed in mg of potassium hydroxide required to neutralize the free acid in 1 g of the resin. Quantification of the weighed resin is dissolved in a solvent such as toluene or THF with neutralized ethyl alcohol and titrated to the phenolphthalein endpoint with a carbonate-free decinormalized potassium hydroxide solution. In addition, the acid value can be measured by the potential difference as described in the following test method. The acid value may be represented by Equation 1 below:

After synthesizing the ester of (meth) acrylic acid, the process of the invention also comprises a neutralization step. The "neutralization" step may be defined as a step in which the acid value of the resin is reduced. The neutralization step includes reacting the free acid group with one or more components, at least one of which forms an ester compound having no β-hydroxy group or at least an amide compound with the acidic (trans) esterification catalyst. .

At least one component that reacts with the free acid group is also considered to be a neutralizing component. The neutralization system is also defined as comprising at least one neutralizing component according to the invention and optionally one or more other components (which can react with free acid groups). The other component may be a β-hydroxy forming component (such as epoxide), an amine, a carbodiimide component or a specific mixture thereof.

If necessary, the neutralization step can be activated by adding a neutralization catalyst.

Free acid groups can be generated from one or more of the following acid groups remaining in the resin after the synthesis step: free catalytic acid, free (meth) acrylic acid groups and / or free carboxylic acid groups.

According to one embodiment, the neutralizing component reacts with the free acid groups generated in the free catalyst acid, free (meth) acrylic acid group and free carboxylic acid group.

According to another preferred embodiment, the neutralizing component according to the invention predominantly reacts with the free catalytic acid.

If one or more of the components react with the free acid groups, the components may all be neutralizing ingredients according to the invention or the ingredients may consist of some neutralizing ingredient (s) and some other ingredient (s).

If a β-hydroxy forming component (such as an epoxide), an amine component, a carbodiimide component, or a particular mixture thereof is present (defined as "other component (s)"), the other component (s) may be neutralized from the outset. And other component (s) are preferably added only after the strong catalytic acid has been neutralized with the neutralizing component according to the invention.

Surprisingly, the ester of (meth) acrylic acid neutralized according to the process of the invention is stable to hydrolysis and does not cloud over time.

The ester or amide compound formed between the catalyst and neutralizing components present in the (meth) acrylic acid ester resin is a compound that is stable to hydrolysis when the resin is stored in an open jar in an oven at 80 ° C. Preferably, the acid value of the resin is opened in an oven at 80 ° C. for at least 1 day, preferably for at least 2 days, more preferably for at least 4 days, particularly preferably for at least 1 week, most preferably for at least 8 weeks. When stored in glass bottles there is no substantial increase.

The at least one neutralizing component may be selected from the group consisting of cyclic ethers, including four-membered cyclic ethers such as oxetane and derivatives, 1,2-dioxetane, 1,3-dioxetane; 5-membered cyclic ethers such as dioxane, dihydrofuran and the like; 6-membered cyclic ethers such as dioxane and its derivatives, dihydropyrans. Other suitable neutralizing components are ortho-esters, esters and lactones, alcohols, carbonates and cyclic carbonates, acetoacetates, chloroformates, chlorosulfites, orthoborates, dialkyl sulfites, urea compounds, such as N, N'- (Bis-2-hydroxyethyl) urea, silyl component, such as bis (trimethylsilyl) sulfate, siloxane component, such as octamethyl cyclo tetrasiloxane, diazo component, such as diazomethane and diazommethyl propylketone, isonitrile, For example phenyl isocyanide, phosphite, such as trialkyl or triaryl phosphite, phosphate, such as trialkyl or triaryl phosphate, phosphonate, such as diethylacetyl phosphonate, tin component, such as dibutyltin oxide . Suitable neutralizing components are also unsaturated components, such as vinyl ethers and cyclic vinyl ethers, allyl ethers, styrenes, olefins and cyclic olefins, maleates, fumarates, acrylates, methacrylates. Other suitable neutralizing components are oxazoline and isocyanates.

Preferred neutralizing components are selected from the group consisting of cyclic ethers, ortho-esters, esters, lactones, alcohols, carbonates, unsaturated components or specific mixtures thereof.

More preferably, the neutralizing component which reacts with the acidic (trans) esterification catalyst is selected from the group consisting of an oxetane component, an ortho-ester component, an alcohol component or a mixture of two or more thereof. Oxetane and ortho-ester components are preferred because they react quantitatively and relatively quickly with acidic catalysts, requiring no long reaction time or excess. Ortho-ester components are preferred because they are readily available and relatively inexpensive. Particularly preferred is the oxetane component, since it does not substantially form byproducts in the ester formation.

Oxetane components or derivatives may be defined by the following general formula (3):

(In Formula 3, X, Y and Z may be the same or different, CR ₂ group, carbonyl (C = O), heteroatom containing group (preferably, oxygen, nitrogen, -NR, phosphorus -PR or P (═O) R), sulfur, etc. The R groups may be the same or different, hydrogen, methyl, ethyl, propyl, butyl, etc .; halogenated alkyls such as chloroalkyl (preferably chloromethyl, chloroethyl), Bromoalkyl (preferably bromomethyl, bromoethyl), fluoroalkyl and iodoalkyl; hydroxyalkyl, such as hydroxymethyl and hydroxyethyl, etc. The oxetane component (3 The oligomer or polymer component containing) may suitably be used as neutralizing agent in the present invention.

The oxetane component usually has at least 58 Mw, preferably at least about 70 Mw, more preferably at least about 101 Mw, even more preferably at least about 115 Mw, most preferably at least about 129 Mw. The Mw of the oxetane component is preferably less than about 10,000, more preferably less than about 8,000.

Suitable examples of oxetane component (3) include oxetane, 3,3-dimethyl-oxetane, 3-bromoethyl-3-methyl-oxetane, 3-chloroethyl-3-methyl-oxetane, 3,3 -Dichloroethyl-oxetane, 3-ethyl-3-hydroxymethyl-oxetane, such as Cyracure® UVR6000, 3-methyl-3-hydroxymethyl-oxetane, 1,4-bis (3 -Ethyl-3-oxetanyl) methoxy, 3-ethyl-3-phenoxymethyl-oxetane, bis {[1-ethyl (3-oxetanyl)] methyl} ether, 3-ethyl-3- [ (2-ethylhexyloxy) methyl] oxetane, 3-ethyl-[(triethoxysilylpropoxy) methyl] oxetane, oxetanyl-silsesquioxane and 3-methyl-3-hydroxymethyl- Oxetane acrylate esters and derivatives thereof, 1,2-dioxetane, 1,3-dioxetane and the like and mixtures of two or more thereof.

Ortho-ester components or derivatives may be defined by the following general formula (4):

(In Formula 4, each of R ¹ to R ³ may be alkyl, cycloalkyl, aryl, etc. Each of R ¹ , R ² or R ³ may be connected to each other to form a ring with each other. R ⁴ is hydrogen ., may be an alkyl, cycloalkyl, aryl-alkyl is, if may be a methyl, ethyl, propyl, butyl R ⁴ is hydrogen, an ortho-ester component is ortho - If a formate component R ⁴ is methyl, the components Is an ortho-acetate compound An oligomer or polymer component comprising said ortho-ester component (4) is suitable for use as a neutralizing agent in the present invention.

The ortho-ester component usually has at least 106 Mw, preferably at least about 118 Mw, more preferably at least about 200 Mw. The Mw of the ortho-ester component is preferably less than about 10,000, more preferably less than about 8,000. Examples of ortho-ester components are trialkyl ortho formate, such as trimethyl ortho formate and trialkyl ortho acetate, such as trimethyl ortho acetate.

As the alcohol neutralizing component, the most well known mono alcohols such as methanol, ethanol and the like; As the alkoxylated alkyl-substituted phenol derivatives, for example, ethoxylated and propoxylated nonylphenols, alkoxylated unsubstituted phenol derivatives, isodecyl alcohol, lauryl alcohol, isobornyl alcohol and the like can be used.

In addition, a wide range of well-known polyalcohols, preferably diols, can be used as the alcohol neutralizing component. Suitable polyalcohols comprise 2-10 alcohol groups, preferably 2-4 alcohol groups. Suitable examples include 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, diethylene glycol, triethylene glycol , Tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, glycerol, trimethylol ethane, trimethylol propane (TMP), neopentyl glycol (NPG), pentaerythritol (PET), dipentaerythritol, sorbitol, 2-methyl-1,3-propane diol, 2,2-dimethyl-1,3-propanediol, 2-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2 -Propyl-2-methyl-1,3-propanediol, 2-propyl-2-ethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol (BEPD), hydroxy pi Valoyl hydroxy pivalate (HPHP), 2-cyclohexyl-2-methyl-1,3-propanediol, 2-phenyl-2-methyl-1,3-propanediol, 1,4-cyclohexanediol, 2 , 4-diethyl-1,5-pentane diol or alkoxylated derivatives of all the above polyalcohols, such as Preferably ethoxylated and propoxylated derivatives thereof, ethoxylated bisphenol-A, propoxylated bisphenol-A, reduced dimer acids and monoesters thereof, and the like. The reduced dimer acid is a hydrogenated analog of dimer acid as described below. The diol component can be used in the mixture.

Preferred alcohols as neutralizing agents are diols having a second hydroxyl group at the γ-position, particularly preferred are 1,3-diol, neopentyl glycol (NPG), 2-butyl-2-ethyl-1,3-propane diol (BEPD) , Trimethylolpropane (TMP), pentaerythritol (PET), monoesters therefrom or mixtures thereof.

Other preferred alcohols as neutralizing agents are monoesters of diols, preferably diols having a second hydroxy in the β- or γ-position relative to the first hydroxy. If alcohol is used as the neutralizing component, the neutralizing step can be activated by adding a neutralizing catalyst such as that described in Boyapati M. Choudary, Tetrahedron 56 (2000) 7291-7298.

Preferably, if only one component reacts with the free acid group, the component reacting with the catalyst is not such an epoxide, amine or carbodiimide component. Nevertheless, mixtures of neutralizing ingredients according to the invention with epoxides or amines are also suitable.

During the neutralization step, the acid value of the resin is preferably about 20 mg KOH / g or less, preferably about 15 mg KOH / g or less, more preferably about 10 mg KOH / g or less, particularly preferably about 5 mg KOH / g or less It is reduced to achieve a value of, most preferably the resin is completely neutralized (acid value <0.1 mg KOH / g resin). Resins with low acid numbers show improved hydrolytic stability.

In the present invention, the acid value AV1 of the acidic catalyst and the acid value AV2 of the remaining acid except for the acidic catalyst are distinguished.

The acid value of the acidic catalyst is defined as the "acid value of the strong acid" and is also defined as AV1 and is a unit of measure for the amount of free catalyst acid remaining in the resin after the (meth) acrylation step. The acid value (AV1) of the acidic catalyst is expressed in mg of potassium hydroxide required to neutralize the free acidic catalyst in 1 g of the resin. According to the present invention, a strong acid can be defined as an acid having a pKa value of about 2 or less as measured at 25 ° C. in water.

The acid value of the remaining free acid, excluding the acidic catalyst, is defined as the "acid value of the weak acid (carboxylic acid)", also defined as AV2, and is a unit of measure for the content of free carboxylic acid and residual (meth) acrylic acid in the resin. The acid value (AV2) is expressed in mg of potassium hydroxide required to neutralize the free carboxylic acid in 1 g of the resin. In accordance with the present invention, weak acids are defined as acids having a pKa of at least about 2.

The neutralization system (preferably the neutralizing component according to the invention, more preferably the oxetane, ortho-ester, alcohol component or a specific mixture thereof) in an amount suitable to obtain an AV1-value of KOH / g resin of less than about 5 mg. Preferably added, more preferably in an amount suitable to obtain AV1 of less than about 3 mg of KOH / g resin, more preferably in an amount suitable to yield AV1 of less than about 2 mg of KOH / g resin, , Particularly preferably in an amount suitable for obtaining AV1 of KOH / g resin of less than about 1 mg, and even more preferably in an amount suitable for obtaining AV1 of KOH / g resin of less than about 0.5 mg, most preferred Preferably in an amount suitable for obtaining AV1 of the KOH / g resin between about 0 and about 0.1 mg.

Preferably at least 10%, more preferably at least 20%, particularly preferably at least 30% of the acidic catalyst. Even more preferably at least 50% is neutralized and most preferably the catalyst is reacted substantially completely.

It is preferred to use the neutralizing component in such an amount that the amount of acidic catalyst used in the synthesis is preferably completely neutralized by using a slight excess of neutralizing component for the determination of the acidic catalyst added in the synthesis.

The ester or amide compound formed between the neutralizing component and the catalyst according to the invention in the ester of (meth) acrylic acid resin is a compound that is stable to hydrolysis when stored in an open glass jar in an 80 ° C. oven. Preferably, the AV1 value of the (meth) acrylic acid ester resin is at least 1 day, preferably at least 2 days, more preferably at least 4 days, particularly preferably at least 1 week, in an open glass bottle in an 80 ° C. oven. Most preferably no increase when stored for at least 8 weeks. For example, when the catalyst is fully reacted by reaction with the neutralizing component according to the present invention, the initial AV1 = 0 and the AV1 value is zero for the specific period above.

The neutralizing system (preferably oxetane, ortho-ester, alcohol component or a specific mixture thereof) is in an amount suitable to obtain a value of AV2 of KOH / g resin of less than about 20 mg, more preferably less than about 15 mg KOH / g In an amount suitable for obtaining the value of AV2 of the resin, particularly preferably in an amount suitable for obtaining the value of AV2 of the KOH / g resin of less than about 5 mg, even more preferably between about 1-5 mg of the KOH / g resin AV2, most preferably in an amount suitable for obtaining AV2 of KOH / g resin between about 0-1 mg.

The neutralizing system (preferably neutralizing component) is about 300 mol% or less, more preferably about 200 mol% or less, more preferably about 150 mol% or less, particularly preferably about 120 mol% relative to the total mol% of the acid groups in the resin. It is added below. With respect to the total mol% of the acid catalyst in the resin, the oxetane or ortho-ester component is preferably added at about 150 mol% or less, more preferably at about 120 mol% or less, particularly preferably at about 105 mol% or less.

The neutralizing system (preferably neutralizing component) is more preferably used in an amount such that the total acid value (AV1 + AV2) is <0.1 mgKOH / g resin, or preferably substantially zero. The neutralizing component is more preferably used in an amount such that the AV2 value is also substantially zero, in addition to the fact that the amount of acidic catalyst used in the synthesis is completely neutralized.

According to a preferred embodiment, the neutralizing component or mixtures thereof of the present invention react predominantly with strong acids having a pKa of about 2 or less, including catalytic acids. And weak acids with pKa-values greater than 2 may use the same or different neutralizing components (or mixtures) according to the invention or β-hydroxy forming components (eg epoxides such as glycidyl methacrylate, Cyclohexene oxide, bisphenol-A-epoxide and the like), amines such as dimethyl amino ethyl acrylate, dimethyl amino propyl acrylate and the like. Neutralized by using carbodiimide or a specific mixture thereof.

More preferably, after the strong acid is neutralized with the neutralizing component of the present invention, the weak acid also reacts with the β-hydroxy forming component (such as epoxide), amine, or carbodiimide, since the components are relatively inexpensive. . Another preferred option is to initiate at least one of the neutralizing components (preferably oxetane, ortho-ester or alcohol components) of the invention in a mixture with an epoxide or amine component, preferably in a mixture with an epoxy component in a neutralization system. It is added to.

Alternatively, certain acids remaining after the neutralization step according to the invention can be removed in other ways, for example by washing with an aqueous base, extraction, distillation, further neutralization or complexation with a solid base. It is preferable to remove certain residual solvents and / or certain residual (carboxyl) acids by vacuum distillation under an air purge. The vacuum distillation is preferably carried out at a temperature in the range of about 100-180 ° C, more preferably about 120-160 ° C, even more preferably about 130-150 ° C. In addition, the vacuum distillation is conducted at less than about 0.5 bar, more preferably less than about 0.1 bar, more preferably less than about 0.01 bar, particularly preferably at about 10 mbar, preferably from about 15 minutes to about 5 hours, more preferably about It takes about 30 minutes to about 4 hours, even more preferably about 1 to 3 hours.

Detailed description of the synthesis method

(Meth) acrylic acid esters and polymers can be prepared and neutralized according to the process of the invention.

In the preparation of (meth) acrylic acid ester monomers, mono alcohol (i) which is well known is methanol, ethanol or the like; Alkoxylated alkyl-substituted phenol derivatives, ethoxylated and propoxylated nonylphenols, alkoxylated unsubstituted phenol derivatives, isodecyl alcohol, lauryl alcohol, isobornyl alcohol, monoesters of ethylene glycol, β- with respect to the first hydroxy group Or monoesters of diols having a second hydroxy group in the γ-position, for example 1,2-diol, for example 1,2-propanediol, 1,2-butanediol, 2,3-butanediol, 2,3 -Pentanediol, monoester of 1,3-diol, etc. can be used.

Also well known polyalcohols, preferably diols, can be used as alcohol (i). Suitable polyalcohols comprise 2-10 alcohol groups, preferably 2-4 alcohol groups. Suitable examples include 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1 9-nonanediol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, glycerol, trimethylol ethane, trimethylol propane, neopentyl glycol, pentaerythritol, Dipentaerythritol, sorbitol, 2-methyl-1,3-propane diol, 2,2-dimethyl-1,3-propanediol, 2-ethyl-1,3-propanediol, 2,2-diethyl-1 , 3-propanediol, 2-propyl-2-methyl-1,3-propanediol, 2-propyl-2-ethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol (BEPD), hydroxy pivaloyl hydroxy pivalate (HPHP), 2-cyclohexyl-2-methyl-1,3-propanediol, 2-phenyl-2-methyl-1,3-propanediol, 1, 4-cyclohexanediol, 2,4-diethyl-1,5-pentane diol or the above polyalcohol As alkoxylated derivative thereof, and for example, preferably including its ethoxylated and propoxylated derivatives thereof, ethoxylated bisphenol -A, propoxylated bisphenol -A, reduced dimer acid. Reduced dimer acids are hydrogenated analogs of dimer acids as described below. The diol component can be used in the mixture.

Ethoxylated bisphenol-A, propoxylated bisphenol-A, neopentyl glycol (NPG), 2-butyl-2-ethyl-1,3-propane diol (BEPD), 2-methyl-1,3-propanediol (MPD ), Hydroxy pivaloyl hydroxy pivalate (HPHP), hydrogenated analogue of dimer acid, 2,4-diethyl-1,5-pentane diol or mixtures thereof. Particularly preferred are NPG, BEPD and 2,4-diethyl-1,5-pentane diol, since the (meth) acrylic acid esters based on these alcohols exhibit surprisingly good hydrolytic stability. It is particularly preferable to use alcohols in which the β-position is substituted for the hydroxy group, more preferably alcohols having no hydrogen in the β-position.

The synthesis method is usually carried out in a one step process in which all of the alcohol compound (i), (meth) acrylic acid (ii) and the catalyst are put in a reactor in air. The reaction can be carried out at atmospheric pressure or at reduced pressure at a temperature in the range of about 80 to 150 ° C, preferably about 100 to 140 ° C, more preferably about 120 to 130 ° C. If present, the solvent is preferably toluene, heptane, xylene, benzene and the like, more preferably toluene. And water is removed azeotropically. The acid value (as described above) or hydroxyl value is monitored at the end of the reaction. The hydroxyl value is a unit for the amount of hydroxyl groups, measured by back titration of the reaction product of the polyester with acetic anhydride, and can be represented by the following equation:

The reaction can be monitored by NMR. The reaction time is usually between about 1 and 24 hours, preferably between about 1 and 16 hours, more preferably between about 2 and 13 hours, particularly preferably between about 5 and 12 hours. If a solvent is present, preference is given to vacuum distillation with certain unreacted (meth) acrylic acids.

The (meth) acrylation reaction is carried out until completion of at least about 50%, more preferably at least about 60%, particularly preferably at least about 70%, even more preferably at least about 95% hydroxyl conversion, according to NMR analysis. desirable. If reactants with relatively high functionality are used, lower hydroxyl conversion is required.

In order to inhibit the polymerization of acrylic double bonds, an inhibition system can be added. Examples of suitable inhibitory systems are hydroquinone, derivatives of hydroquinone, such as methylether hydroquinone, 2,5-dibutyl hydroquinone (DBH), benzoquinone, derivatives of benzoquinone, such as methylether benzoquinone, 2,5-dibutyl Examples of copper (II) salts such as nitrobenzene, nitrostyrene, and phenothiazine, such as benzoquinone, include Cu (II) naphtanate and the like. Of these, 2,5-dibutyl hydroquinone (DBH) is preferred because the discoloration of the final oligomer is relatively lower.

In addition, stabilizers can be used in the process, in particular color stabilizers such as trisnonyl phenol phosphite (TNPP), trisphenol phosphite (TPP), bis- (2,4-di-t-butyl-phenyl) pentaeryte Ritol-di-phosphite and the like can be used.

In the preparation of the (meth) acrylic ester polymers of the invention, preferred polyalcohols (i) are polyether alcohols such as polyethylene glycol (PEG), polypropylene glycol (PPG), polytetramethylene glycol (PTMG), PTMG and Copolymers of methyl-substituted PTMG (PTGL), copolymers of ethylene oxide and butylene oxide, and the like; Polyester alcohols, hydrocarbon alcohols and the like. Hydrocarbon-based alcohols may include linear or branched hydrocarbons comprising a plurality of hydroxyl end groups. "Hydrocarbon" means a non-aromatic compound mainly comprising methylene groups and may include internal unsaturated groups and / or pendant unsaturated groups. Fully saturated (eg hydrogenated) hydrocarbons are preferred. Suitable hydrocarbon polyols include, but are not limited to, hydroxyl-terminated, fully or partially hydrogenated 1,2-polybutanediene polyols, 1,2-polybutadiene polyols hydrogenated with iodines from 9 to 21; Fully or partially hydrogenated polyisobutylene polyols, polybutene polyols, hydrogenated dimer diols, mixtures thereof, and the like. Preferably the hydrocarbon polyol is substantially fully hydrogenated, and therefore the preferred polyol is hydrogenated 1,2-polybutadiene.

Since the process of the present invention is difficult to wash high viscosity components, while the neutralization step of the present invention is beneficial, in the synthesis of polymerizable esters of (meth) acrylic acid, more preferably in the synthesis of polyester (meth) acrylates Can be advantageously used. The neutralization method of the present invention was found to be beneficial in the preparation of terminal standing diacrylates. An additional advantage is that the catalyst used in the preparation of the polyester polyols is used in successive acrylated steps and therefore does not require a cleaning step.

Preference is given to polyester acrylates having a relatively small amount of ester linkages. Also preferred are hydrophobic polyester acrylates. In order to obtain a more hydrolytically resistant polyester acrylate, its building blocks can be modified, for example by selecting more hydrolytically stable and / or more stericly hindered building blocks of polyhydric acids and / or alcohols. Can be. Polyester acrylates with reduced acid value may also be selected.

The polyester main chain according to the invention is derived from (i) polyalcohols and (ii) saturated or unsaturated polyhydric acids to give polyester polyols. Saturated polyhydric acids and polyalcohols are preferred. The polyester polyol is reacted with (iii) acrylic acid or methacrylic acid to obtain a polyester (meth) acrylate.

Preferred polyester acrylates comprise about 0.5 to 20 diacids, more preferably about 1 to about 5, particularly preferably about 2 to about 4, most preferably at least about 2.5.

If the polyester is an alkyd, the alkyd can be made by any method. Preferably, the alkyd resin can be prepared by the condensation reaction of a polyfunctional alcohol (hereinafter referred to as polyol), a polyfunctional carboxylic acid (hereinafter referred to as polyacid) and an oil or fatty acid derived from oil. The oil may be a natural oil (comprised of esters, for example of glycerol and triesters of fatty acids). For example, polyol / fatty acid mixtures can be prepared in situ by alcoholation of naturally derived oils or by direct esterification of naturally occurring long chain fatty acids and polyols. The product from any of the above reactions can be polymerized with other polyols and polyacids (eg diols and diacids) by conventional polyesterification. More preferably the alkyd is prepared by alcoholication of a naturally derived oil, preferably alcoholic with low unsaturations.

As (i) polyalcohols, well-known polyalcohols can be used as described above in the preparation of (meth) acrylic acid ester monomers.

(ii) As polyacids for polyesters and / or alkyd acrylates, polyfunctional carboxylic acids and the corresponding anhydrides can be used. Preferably, aromatic or aliphatic divalent carboxylic acids and corresponding anhydrides, such as phthalic acid or anhydride, isophthalic acid, terephthalic acid, maleic or anhydride, fumaric acid, itaconic acid or anhydride, adipic acid, glutaric acid, azelaic acid, seba Succinic acid, citric acid, trimellitic acid or anhydride, pyromellitic acid or dianhydride, dodecane dicarboxylic acid, dodecane dioic acid, cyclohexane dicarboxylic acid, tetrahydrophthalic anhydride, methylene tetrahydrophthalic acid or anhydride, hexahydro Phthalic anhydride, succinic acid or acid anhydride thereof or lower alkyl esters thereof, dimer-fatty acid and the like are used. Mixtures of acids can also be used.

Dimer acids (and esters thereof) are known in the commercially available class of dicarboxylic acids (or esters). They are usually prepared by dimerization of unsaturated long chain aliphatic monocarboxylic acids or their esters (eg alkyl esters) of 13 to 22 carbon atoms. The dimerization can be proceeded by self-probable mechanisms having ordinary skill in the art, which mechanisms include Diels-Alder, free radical and carbonium ion mechanisms. Dimer acid materials typically contain 26 to 44 carbon atoms. In particular dimer acids (or esters) derived from C-18 and C-22 unsaturated monocarboxylic acids (or esters) which give C-36 and C-44 dimer acids (or esters). Dimer acids derived from C-18 unsaturated acids, including acids such as linoleic acid and linolenic acid, are particularly well known (obtaining C-36 dimer acid).

The dimer acid product will typically include some trimer acids (eg, C-54 acids when using C-18 starting acid), higher oligomers, and minor monomeric acids. Several different grades of dimer acids are available from commercial sources, which differ in monovalent and trimeric acid fractions and degrees of unsaturation.

Normally the dimer acid (or ester) product formed initially is unsaturated, detrimental to oxidative stability by providing a site for crosslinking or degradation, thereby changing the physical properties of the coating film over time. It is therefore desirable to use hydrogenated dimer acid products to remove substantial portions of unreacted double bonds.

By "dimer acid" is meant here the diacid material itself or its ester-forming derivatives (eg lower alkyl esters) and specific trimers or monomers (if present) which act as acid components in polyester synthesis. .

Particular preference is given to adipic acid, isophthalic acid, terephthalic acid and dimer-fatty acids or mixtures thereof. Also preferred are tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 1,4-cyclohexane dicarboxylic acid (CHDA), succinic acid or mixtures thereof. The acid based polyester acrylates exhibit good hydrolytic stability.

For alkyds, the monoacid can be a specific monocarboxylic acid having 4 to 28 carbon atoms. Preferably the monoacid is a fatty acid, more preferably a long chain monoacid. Long chain monovalent acids or long chain fatty acids are characterized by having from 12 to 28 carbon atoms, more preferably from 12 to 24 carbon atoms in the chain. The largest fatty acids have 18 carbon atoms in the chain, but naturally derived oils are capable of more carbon atoms. For example, the C ₂₂ acid, Erusic acid (dococenoic acid), has been found in several variants of rapeseed oil. Preferably, the naturally derived fatty acid or fatty acid derived oil is a fatty acid or oil derived from a vegetable or animal to those of ordinary skill in the art.

Suitable fatty acids or oils in the alkyd main chain according to the invention may be unsaturated or saturated. Preferably the fatty acid or oil has a low degree of unsaturation as defined below. Examples of unsaturated oils or fatty acids (derived from oils) include castor oil, corn oil, cottonseed oil, rapeseed oil, low erucane rapeseed oil, hempseed oil, kapok oil, linseed oil, wild mushrooms, otissica oil, olive oil. , Palm oil, peanut oil, perilla oil, poppy seed oil, tobacco seed oil, argentine rapeseed oil, rubber seed oil, safflower oil, perilla oil, soybean oil, sugarcane oil, sunflower oil, tall oil, tea seed oil, tung oil, Black walnut oil or mixtures thereof and the like.

Examples of fatty acid oils with low unsaturation are coconut oil, babass oil, Chinese tall oil, ulical oil, palm kernel oil, caprylic acid, caproic acid, capric acid, coconut fatty acid, lauric acid, myristic acid, pal In the hydrogenated form of fatty acids derived from oils, as well as fatty acids derived from oils, stearic acids and the like, as well as unsaturated oils and oils, such as castor oil, corn oil, cottonseed oil, rapeseed oil, lower erucane rapeseed oil , Hempseed oil, kapok oil, linseed oil, wild mushrooms, cucumber tea, olive oil, palm oil, peanut oil, perilla oil, poppy seed oil, tobacco seed oil, argentine rapeseed oil, rubber seed oil, safflower oil, Perilla oil, soybean oil, sugar cane oil, sunflower oil, tall oil, tea seed oil, tung oil, black walnut oil, mixtures thereof, and the like.

(iii) (meth) acrylation of (poly) ester polyols is finally carried out with (meth) acrylic acid or lower alkyl esters thereof as defined in formula (1). Lower alkyl esters preferably have 1-6 carbon atoms.

Polymerizable (trans) esterification, in particular the preparation of polyester (meth) acrylates, can be carried out in one step, two steps or more process steps.

In a one step process, the alcohol component (i), acid component (ii), (meth) acrylic acid (iii) and the catalyst are all put into the reactor in air and the same reaction conditions as in the monomer esterification described above are applied.

According to a preferred embodiment according to the invention, the (poly) ester (meth) acrylate is prepared in a two step synthesis process, especially when one of the components, for example, the solubility of one of the acids is poor. During the first step of the two-step process, the (poly) ester polyol is preferably acid (ii) and alcohol (at a temperature of about 150-250 ° C., preferably 160-240 ° C., more preferably 180-230 ° C., under a nitrogen atmosphere. i) The components are prepared by esterification. Solvents may be present as described above. Preferably, the reaction is carried out under pressure, more preferably at a pressure of about 10 bar or less, particularly preferably about 6 bar or less, more preferably 2 bar or less. Usually, an excess alcohol component is used in comparison to the acid component to obtain a hydroxyl functional compound.

As the (trans) esterification catalyst in the first step, organic acids, inorganic acids and metal catalysts are effective. Among these, organic acid catalysts and metal catalysts are preferred because of their high purity and their effectiveness as catalysts. As the organic acid catalyst, alkyl sulfonic acids such as methane sulfonic acid, aryl sulfonic acid, such as p-toluene sulfonic acid, benzene sulfonic acid and the like can be provided. As the inorganic catalyst, sulfuric acid, phosphoric acid and the like can be provided. As metal catalysts, tetra-isopropyl titanate, tetra-phenyl titanate, hydroxy titanium stearate, tetra-stearyl titanate, tetraethyl zirconate, tetra butoxy titanate ((BuO) ₄ Ti, dibutyl Tin oxide (Bu ₂ -SnO), butyl stannoic acid (BuSnOOH), butyl tin chloro dihydroxy (BuSnCl (OH) ₂ )), and the like. P-toluene sulfonic acid is particularly preferred because of its high effectiveness and low cost. Preference is given in particular to butyl stannic acid and butyl tin chloro dihydroxy, since only small amounts of catalyst are required to exhibit relatively high reactivity, especially at high temperatures of the first stage reaction.

In the two-step process, the second step is the reaction conditions in which the (meth) acrylation of the (poly) ester diol of the first step is as described in the one-step reaction, for example, under temperature and reaction time. The reaction is preferably carried out (by air purge) by adding (meth) acrylic acid to a solvent such as toluene in the presence of a catalyst and an inhibition system to stabilize the acrylic unsaturated group.

The Mn of the polyester polyols is usually between about 400 and about 14,500, preferably between about 500 and about 10,000, more preferably between about 600 and about 9,000.

Typically the OH-functional groups of the polyester main chain will be less than about 5, more preferably less than about 3. Typically the functionality of the polyester main chain will be at least about 1.5, preferably at least about 1.8. Preferably the functionality is between about 2.0 and 2.5.

Esters of (meth) acrylic acid prepared according to the invention can be solid or liquid and can be used in a wide range.

One application is for example coatings, wet aqueous or solid (so-called powder) coatings. Wet coatings can be divided into solvent based and 0% VOC (volatile organic compound) systems. 0% VOC system means a system free of solvents; In some cases, very low amounts of volatiles can be avoided during curing of solid components.

All of these coatings can be applied to untreated or pre-coated wood, wood like materials, glass, metal, plastic and hybrid surfaces. Examples of wood-like materials are plywood, chipwood and MDF (medium density fiber board). Hybrid surface is meant to include other materials, for example combinations of metal and wood.

The curing mechanism of the coating composition is not particularly important. It may be cured by heat or by radiation. Preference is given to using esters of (meth) acrylic acid in coating compositions which can be cured by UV-radiation. If UV-radiation is used, it is preferable to use UV-initiating curing agents as photoinitiators, for example in the presence of Norrish type 1 and type 2 photoinitiators. When thermal curing is applied, preference is given to using radical-initiated curing agents in the presence of peroxides (alone or in combination with accelerators), for example azo-isobutyl-nitrile (AIBN) and cobalt-compounds.

Esters of (meth) acrylic acid can be used in coating compositions as sole binders, as well as in combination with binders based on the same or different techniques.

For example, in powder coatings, it is possible to obtain esters of crystalline and / or semicrystalline (meth) acrylic acid and amorphous (meth) acrylic acid esters and obtain good fluidity combined with good powder stability and good process properties. As binders that are completely different from crystalline and / or semicrystalline (meth) acrylic acid esters, amorphous GMA-functional polyesters as described, for example, in patent WO 98/18862 can be combined.

In solvents and / or 0% VOC systems, esters of (meth) acrylic acid can be used in coating compositions as sole binders, as well as in combination with other oligomers, reactive diluents and solvents.

In aqueous systems, esters of (meth) acrylic acid are described in Emulsion Polymerisation, Theory and Practice, Ed. D.C. It may be dispersed or emulsified in water using standard techniques such as those described in Blackley, Applied Science Publishers, London 1975, ISBN: 0 85334 627 5.

Other applications of (meth) acrylic acid esters include reactive hot melt adhesives, sizing and binder resins, dental applications, contact lenses, optical disc adhesives (e.g. DVD, CD or CD-R), hard coats and solids It can be used for flat printing. Esters of (meth) acrylic acid are also used as composite resin compositions, such as sheet molding compounding (SMC) resins, casting resins, extruded resins, styrene resins with low or zero content, hand layup resin transfer moldings, prepregs and the like. And may be used, for example, in the manufacture of molded parts, structural elements, glass fiber laminates, and the like.

Description of the test method

How to measure acid value (AV)

About 2 g of sample is diluted in 25 ml of THF. And 1 ml of water is added to dissociate the acid (s) into (their) ions. The mixture is stirred for 5 minutes and then potentiometrically titrated with 0.1 M potassium hydroxide in methanol standard solution (KOH / MeOH). Acid values (acid AV1 with pKa ≦ 2 and acid AV2 with pKa> 2) are automatically measured in a Toledo DL58 titrator.

Also, in order to measure the strong acid value AV1 more accurately, the amount of sample can be increased. The appropriate amount of sample depends on the expected acid value. Some guidelines are:

AV <1:> 2g sample

1 <AV <100: 0.5-2g of sample

AV> 100: <0.5 g of sample

The acid value is automatically calculated based on Equation 3:

(In Equation 3, AV = acid value,

V _eq = volume (mL) of titrant used at the equivalence point

t = 0.1 n KOH

m = amount of sample (g))

Examples and Comparative Experiments

Example 1-3 Synthesis of (meth) acrylate Monomer

Example 1 Synthesis of Phenoxyethyl Methacrylate

Phenoxyethanol is mixed with 105 mol% methacrylic acid followed by the addition of 30% toluene, 1% PTSA, 0.1% dibutylhydroquinone (based on the amount of alcohol + methacrylic acid). Purge air into the reaction mixture and raise the temperature until toluene boils. The mixture is then refluxed (120-130 ° C.) for 8 hours in a flask equipped with Dean-Stark apparatus and the reaction water is removed.

After 8 hours, a sample is taken and potentiometrically titrated to determine the acid value (AV1) containing free PTSA and the acid value (AV2) of carboxylic acid. Next, 105 mol% (relative to AV1 of PTSA) 3-ethyl-3-hydroxymethyl-oxetane is added to neutralize PTSA. After 15 minutes, a sample is taken to confirm that AV1 = 0, and the solvent and residual methacrylic acid are continuously removed by distillation at 130 ° C and 50 mmHg. The final values are AV1 = 0 and AV2 = 16.4.

Example 2: Synthesis of Ethoxylated (Average 2x) Bisphenol A Dimethacrylate

Ethoxylated (average double) bisphenol A dimethacrylate is prepared in the same manner as in Example 1, but is initiated in ethoxylated bisphenol A instead of phenoxyethanol, and the inhibition system is 8 ppm Cu (II) naphthenate Includes. The final values are AV1 = 0 and AV2 = 2.5.

Example 3: Synthesis of Trimethylol Propane Trimethacrylate

Trimethylol propane trimethacrylate is prepared in the same manner as in Example 1, but trimethylol propane is used as starting material instead of phenoxyethanol. The final values are AV1 = 0 and AV2 = 2.8.

Example 4-5: Synthesis of Polyether (meth) acrylate

Example 4 Synthesis of Polytetrahydrofuran Diacrylate

Polytetrahydrofuran Mn = 1000 is mixed with 105 mol% acrylic acid (relative to the amount of OH) and then 30% toluene, 1% PTSA, 0.1% dibutylhydroquinone (based on all amounts of alcohol + acrylic acid) Is added. Purge air through the reaction mixture and raise the temperature until toluene boils. The mixture is then refluxed (120-130 ° C.) for 8 hours in a flask equipped with Dean-Stark apparatus and the reaction water is removed.

After 8 hours, a sample is taken and potentiometrically titrated to determine the acid value (AV1) containing free PTSA and the acid value (AV2) of carboxylic acid. Next, 105 mol% (relative to AV1 of PTSA) 3-ethyl-3-hydroxymethyl-oxetane is added to neutralize PTSA. After 15 minutes, a sample is taken to confirm that AV1 = 0, and the solvent and residual acrylic acid are subsequently removed by distillation at 130 ° C and 50 mmHg. The final values are AV1 = 0 and AV2 = 1.5.

Example 5: Synthesis of Polyethyleneglycol Dimethacrylate

Triethylene glycol is methacrylated in the same manner as in Example 4, and the inhibition system comprises 8 ppm Cu (II) naphthenate. The final values are AV1 = 0 and AV2 = 11.6.

Example 6: Synthesis of Liquid Polyester Acrylate I-IV

Polyester acrylates I-IV are prepared according to the two step synthesis process as described above. In the first step, isophthalic acid (IPA) is reacted with BEPD (2-butyl-2-ethyl-1,3-propanediol) in the presence of 0.2% (relative to the total amount of IPA and BEPD) BuSnOOH as catalyst. The first stage is stopped when the acid value AV is less than 5 and all IPA is dissolved.

Typical experimental conditions of the second stage are as follows:

Amount of acrylic acid (AA) 105 mol% Amount of toluene 35 wt.% (Based on total amount of IPA + BEPD + AA) -Amount of PTSA 1 wt.% (Based on IPA + BEPD + AA) -Inhibition system 1000 ppm DBH, 1000 ppm TNPP, air purge (1ℓ / hr / ℓ) Reaction temperature 125-130 ℃ Reaction time 12-16 hours (to OH conversion of> 95% by NMR) -PTSA neutralization Reaction with 150 mol% neutralizer Solvent Distillation 120 ° C. and 20 mbar (until the amount of toluene remaining is less than about 0.5%)

The amount of reactants used in the process is provided for each polyester acrylate I-IV:

Polyester acrylate I: 5 mol BEPD neutralized with 3-ethyl-3-hydroxymethyl-oxetane (UVR-6000), 4 mol IPA and 2 mol AA, theoretical Mn = 1428

Polyester acrylate II: 5 mol BEPD neutralized with trimethyl ortho formate, 4 mol IPA and 2 mol AA, theoretical Mn = 1428

Polyester acrylate III: 3.5 mol BEPD neutralized with 3-ethyl-3-hydroxymethyl-oxetane (UVR-6000), 2.5 mol IPA and 2 mol AA, theoretical Mn = 1020

Polyester acrylate IV: 6.5 mol BEPD neutralized with 3-ethyl-3-hydroxymethyl-oxetane (UVR-6000), 5.5 mol IPA and 2 mol AA, theoretical Mn = 1880.

Example 7: Synthesis of Liquid Alkyd Acrylate V

The alkyd acrylate V is prepared according to a three step synthesis process.

In the first step, 1 mol of coconut fatty acid (Prifac 7901 of Unichema) is reacted with 1 mol of trimethylol propane (TMP) with BuSnOOH at 185 ° C. until the acid value is less than 5. In the second step, the fatty acid diol is reacted with 3 mol neopentyl glycol (NPG), 2 mol IPA and 1 mol adipic acid (ADA) until the acid value is less than 5 to produce an alkyd polyol. In the last step, the polyol is acrylated with acrylic acid while refluxing (130 ° C.) toluene with 1% PTSA as catalyst. OH-conversion is according to NMR. After about 95% conversion, PTSA is neutralized with 200% 3-ethyl-3-hydroxymethyl-oxetane (UVR-6000) (for AV1 of PTSA) and the solvent is evaporated. Finally a yellow viscous resin is obtained (GPC Mn / Mw = 1600/4800).

Example 8-9 and Comparative Experiment 1-2: Synthesis and Neutralization Method of Liquid Polyester Acrylate VI

Synthetic Method:

First step. Synthesis of Polyester Polyol : 1 mol of isophthalic acid and 2 mol of butylethylpropanediol (BEPD) are esterified with 0.1% BuSnCl (OH) ₂ as catalyst at 180-220 ° C. up to the acid value.

Second step. Acrylation stage : The polyester polyol of the first stage is cooled to 100 ° C. and 105 mol% of acrylic acid (relative to the amount of OH), 30% toluene, 1% PTSA and 0.1% dibutylhydroquinone DBH (polyester For all amounts of polyol + acrylic acid). The air is purged through the reaction mixture and the temperature is increased until toluene is boiled. The mixture is then refluxed (120-130 ° C.) for 8 hours in a flask equipped with a Dean-Stark apparatus and the reaction water is removed. If necessary, lower the pressure and maintain reflux of toluene. After 8 hours, a sample is taken and potentiometrically titrated to determine the acid value (AV1) containing free PTSA and the acid value (AV2) of carboxylic acid. The AV1 is 2.5 and the AV2 is 8.8. The liquid polyester acrylate resin VI is then divided into five parts.

Neutralization method:

Example 8:

The resin is neutralized with 3-methyl-3-hydroxymethyl-oxetane at 150 mol% (relative to AV1 of PTSA). After 15 minutes, a sample is taken to confirm that AV1 = 0 and the solvent and residual acrylic acid are subsequently removed by distillation at 130 ° C. and 50 mm Hg.

Example 9:

The resin is neutralized with 150 mol% of trimethyl ortho formate (relative to AV1 of PTSA). After 15 minutes, a sample is taken to confirm that AV1 = 0 and the solvent and residual acrylic acid are subsequently removed by distillation at 130 ° C. and 50 mm Hg.

Comparative Experiment 1:

The resin is not neutralized and the solvent and residual acrylic acid are removed by distillation at 130 ° C. and 50 mm Hg.

Comparative Experiment 2:

The resin is neutralized with 150 mol% glycidyl methacrylate (relative to AV1 of PTSA). After 15 minutes, a sample is taken to confirm that AV1 = 0 and the solvent and residual acrylic acid are subsequently removed by distillation at 130 ° C. and 50 mm Hg.

To test the hydrolytic stability, 20 g of samples of the resins of Examples 8-9 and Comparative Experiments 1-2 are stored in an open glass jar in an oven at 80 ° C. After several time intervals the strong acid value AV1 (= PTSA) and weak acid value AV2 (= carboxylic acid) are measured.

As disclosed in Table 1, samples neutralized with oxetane (Example 8) or ortho ester (Example 9) do not show strong acid even after 8 weeks (AV1 = 0). This is in comparison to the unneutralized sample (Comparative Experiment 1) and the glycidyl methacrylate neutralized sample (Comparative Experiment 2) and clearly shows the presence of PTSA.

Hydrolysis Stability of Liquid Polyester Acrylate VI at 80 ° C Example 83 Me-3-hydroxy-Me-oxetane Example 9 Trimethyl Ortho Formate Comparative Experiment 1 No Neutralization Comparative Experiment 2 Glycidyl Methacrylate Time at 80 ℃ AV ₁ AV ₂ AV ₁ AV ₂ AV ₁ AV ₂ AV ₁ AV ₂ 0 days 0.0 8.7 0.0 12.1 2.5 8.8 0.0 8.6 1 day 0.0 9.3 0.0 11.2 2.5 9.2 1.0 7.2 4 days 0.0 9.0 0.0 9.7 2.6 10.3 1.7 8.1 1 week 0.0 9.2 0.0 8.8 2.6 10.3 1.7 8.7 2 weeks 0.0 9.0 0.0 7.7 2.4 8.4 2.0 7.6 5 Weeks 0.0 8.2 0.0 7.5 2.1 7.0 2.1 6.6 8 Weeks 0.0 7.9 0.0 8.2 2.3 6.6 2.0 7.1

Example 10-11 Synthesis and Neutralization Method of Liquid Polyester Acrylate VII

Synthetic Method:

First step. Synthesis of Polyester Polyol : 3.5 mol of isophthalic acid, 2 mol of adipic acid and 6.5 mol of butylethylpropanediol (BEPD) were 0.1% BuSnCl (OH) ₂ at 180-220 ° C. until the acid value was less than 5. Esterification.

Second step. Acrylation step : The polyester polyol of the first step is cooled to 100 ° C., 105 mol% of acrylic acid (relative to the amount of OH), 15% toluene, 1% PTSA and 0.1% dibutylhydroquinone (polyester polyol) + For all amounts of acrylic acid). The air is purged through the reaction mixture and the temperature is increased until toluene is boiled. The mixture is then refluxed (120-130 ° C.) for 8 hours in a flask equipped with a Dean-Stark apparatus and the reaction water is removed. If necessary, lower the pressure and maintain reflux of toluene. After 8 hours, a sample is taken and potentiometrically titrated to determine the acid value (AV1) containing free PTSA and the acid value (AV2) of carboxylic acid.

Neutralization method:

Example 10:

Next, 105 mol% (relative to AV1 of PTSA) 3-ethyl-3-hydroxymethyl-oxetane is added to neutralize PTSA. After 15 minutes, a sample is taken to confirm that AV1 = 0, and the solvent and remaining acrylic acid are subsequently removed by distillation at 130 ° C. and 50 mm Hg. The final value is AV1 = 0 and AV2 = 8.0.

Example 11:

To neutralize the strong acid, 300 mol% (relative to the amount of added PTSA) of neopentyl glycol is added. Reflow is continued until AV1 goes to zero. Subsequently, the solvent and remaining acrylic acid are removed by distillation at 130 ° C. and 50 mm Hg. The final value is AV1 = 0 and AV2 = 3.0.

Example 12 Synthesis and Neutralization Method of Liquid Polyester Acrylate VII

The synthesis method of Example 10 is repeated using 0.5% H ₂ SO ₄ instead of 1% PTSA as the catalyst of the second step. The final value is AV1 = 0 and AV2 = 9.0.

Example 13: Synthesis and Neutralization Method of Liquid Polyester Methacrylate VIII

First step. Synthesis of Polyester Polyol : 1 mol of phthalic anhydride, 1.8 mol of triethylene glycol and 0.2 mol of trimethylol propane are esterified with 1% PTSA at 180 ° C until the acid value is less than 10. To improve the removal of water, 3% toluene is added and a Dean-Stark apparatus is used.

Second step. Methacrylation step : The polyester polyol of the first step is cooled to 100 ° C., 105 mol% methacrylic acid (relative to the amount of OH), 15% toluene, 1% PTSA and 0.1% dibutylhydroquinone (For all amounts of polyester polyol + methacrylic acid). The air is purged through the reaction mixture and the temperature is increased until toluene is boiled. The mixture is then refluxed (120-130 ° C.) for 8 hours in a flask equipped with a Dean-Stark apparatus. If necessary, lower the pressure and maintain reflux of toluene. After 8 hours, a sample is taken and potentiometrically titrated to determine the acid value (AV1) containing free PTSA and the acid value (AV2) of carboxylic acid.

Next, 105 mol% (based on added PTSA) 3-ethyl-3-hydroxymethyl-oxetane is added to neutralize PTSA. After 15 minutes, a sample is taken to confirm that AV1 = 0, and the solvent and residual acrylic acid are subsequently removed by distillation at 130 ° C. and 50 mm Hg. The final value is AV1 = 0 and AV2 = 12.0.

Example 14 Synthesis and Neutralization Method of Solid Amorphous Polyester Acrylate IX

First step. Synthesis of polyester polyol : 20 mol terephthalic acid, 20 mol neopentyl glycol and 1 mol trimethylol propane are esterified with 0.1% BuSnCl (OH) ₂ at 180-240 ° C. until the acid value is <10. .

Second step. Acrylation stage : The polyester polyol of the first stage is cooled to 120 ° C., 105 mol% of acrylic acid (relative to the amount of OH), 15% toluene, 1% PTSA and 0.2% dibutylhydroquinone (polyester polyol) + For all amounts of acrylic acid). The air is purged through the reaction mixture and the temperature is increased until toluene is boiled. The mixture is then refluxed (120-140 ° C.) for 8 hours in a flask equipped with Dean-Stark apparatus. If necessary, lower the pressure and maintain reflux of toluene. After 8 hours, a sample is taken and potentiometrically titrated to determine the acid value (AV1) and the acid value (AV2) of the carboxylic acid containing free PTSA.

Next, 105 mol% (relative to AV1 of PTSA) 3-ethyl-3-hydroxymethyl-oxetane is added to neutralize PTSA. After 15 minutes, a sample is taken to confirm that AV1 = 0, and the solvent and residual acrylic acid are subsequently removed by distillation at 160 ° C. and 50 mm Hg. The final value is AV1 = 0 and AV2 = 8.9.

Example 15 Synthesis and Neutralization Method of Solid Semicrystalline Polyester Acrylate X

First step. Synthesis of polyester polyol : 3.5 mol terephthalic acid and 4.5 mol hexanediol are esterified with 0.1% BuSnCl (OH) ₂ at 180-240 ° C. until the acid value is less than 5.

Second step. Acrylation stage : The polyester polyol of the first stage is cooled to 100 ° C. and 105 mol% of acrylic acid (relative to the amount of OH), 15% toluene, 1% PTSA and 0.2% dibutylhydroquinone (polyester polyol) + For all amounts of acrylic acid). The air is purged through the reaction mixture and the temperature is increased until toluene is boiled. The mixture is then refluxed (120-140 ° C.) for 8 hours in a flask equipped with Dean-Stark apparatus. If necessary, lower the pressure and maintain reflux of toluene. After 8 hours, a sample is taken and potentiometrically titrated to determine the acid value (AV1) containing free PTSA and the acid value (AV2) of carboxylic acid.

Next, 105 mol% (relative to AV1 of PTSA) 3-ethyl-3-hydroxymethyl-oxetane is added to neutralize PTSA. After 15 minutes, a sample is taken to see if AV1 = 0, and the solvent and remaining acrylic acid are subsequently removed by distillation at 160 ° C. and 50 mm Hg. The final value is AV1 = 0 and AV2 = 8.0.

As described above, the present invention provides a process for the preparation of esters of (meth) acrylic acid in the presence of an acidic (trans) esterification catalyst and in particular a complex cleaning step which is essential for removing the free acid groups of the acidic catalyst. The ester of (meth) acrylic acid having excellent hydrolytic stability is obtained by the method of the present invention, and the resin containing the ester of (meth) acrylic acid is stable to hydrolysis and does not cloud over time. Has additional advantages.

Claims (25)

In the process for producing an ester of (meth) acrylic acid by (trans) esterification of a monovalent or polyhydric alcohol with (meth) acrylic acid or an ester derivative thereof in the presence of an acidic (trans) esterification catalyst, Reacting the remaining acid groups with one or more component (s) after formation of an ester of (meth) acrylic acid, wherein at least one component forms an ester compound having no β-hydroxy group at least with the catalyst or an amide compound Forming method of the ester of (meth) acrylic acid characterized by the above-mentioned. The method of claim 1, And said at least one component forms an ester compound having no β-hydroxy group at least with said catalyst. The method according to claim 1 or 2, When a β-hydroxy forming component, an amine component, a carbodiimide component, or a mixture of two or more thereof is present, the acidic catalyst forms at least one component which forms an ester compound having no β-hydroxy group or forms an amide compound. The method of producing an ester of (meth) acrylic acid, wherein the component (s) is added only after neutralization. The method according to any one of claims 1 to 3, The at least one component is a method for producing an ester of (meth) acrylic acid, characterized in that additionally forming an ester compound having no β-hydroxy group or an amide compound in addition to the remaining acid groups. The method of claim 5, The remaining free acid group includes a free (meth) acrylic acid group and a free carboxylic acid group. The method according to any one of claims 1 to 5, Said at least one component is selected from the group consisting of cyclic ethers, ortho-esters, esters, lactones, alcohols, carbonates, unsaturated components or mixtures thereof. The method of claim 6, Wherein said at least one component is selected from the group consisting of an oxetane component or derivative, an ortho-ester component, an alcohol component or a mixture of two or more thereof. The method of claim 7, wherein Said at least one component in the group consisting of 3-ethyl-3-hydroxymethyl-oxetane, 3-methyl-3-hydroxymethyl-oxetane, trialkyl ortho formate, trialkyl ortho acetate and neopentylglycol A process for producing an ester of (meth) acrylic acid, characterized in that it is selected. The method according to any one of claims 1 to 8, The neutralization system comprising at least one component is a method for producing an ester of (meth) acrylic acid, wherein the acid value (AV1) of the acidic catalyst is added in an amount suitable to obtain a KOH / g resin of less than about 2 mg. The method according to any one of claims 1 to 9, The neutralization system comprising at least one component is an ester of (meth) acrylic acid, characterized in that the acid value (AV2) of the free acid excluding the acidic catalyst is added in an amount suitable to obtain a KOH / g resin of less than about 20 mg. Manufacturing method. The method of claim 10, Wherein said neutralizing system comprises at least one component selected from the group consisting of β-hydroxy forming component, amine component and carbodiimide component and at least one component. The method according to any one of claims 1 to 11, Wherein said neutralizing system is added in an amount of up to about 300 mol% relative to the total amount of acids. The method according to any one of claims 1 to 11, Said at least one component is added in 105 mol% or more with respect to the total mol% of an acid catalyst, The manufacturing method of the ester of (meth) acrylic acid. The method according to any one of claims 1 to 13, The ester of (meth) acrylic acid is a method of producing an ester of (meth) acrylic acid, characterized in that (meth) acrylate functional polyester or polyalkyd. The method according to any one of claims 1 to 14, The acid catalyst is selected from the group consisting of sulfuric acid, phosphoric acid and its monoester, para-toluene sulfonic acid, benzene sulfonic acid, styrene sulfonic acid and methane sulfonic acid. In the process for producing esters of (meth) acrylic acid resins by (trans) esterification of mono- or polyhydric alcohols with (meth) acrylic acid or ester derivatives thereof in the presence of an acidic (trans) esterification catalyst, Reacting the remaining acid groups with one or more component (s) after forming an ester of (meth) acrylic acid, wherein the acid value of the resin is substantially lower when stored in an open glass jar at 80 ° C. for at least one day. At least one component is selected so as not to be increased. The acid value of the resin is not substantially increased when stored in an open glass jar in an oven at 80 ° C. for at least 1 day, characterized in that it is obtained according to the method of any one of claims 1 to 16 (meth). Esters of acrylic acid resins. The method of claim 17, AV1 value of the resin is less than about 2 mg KOH / g resin, ester of (meth) acrylic acid resin. In the method of neutralizing an acidic (trans) esterification catalyst in a reaction mixture containing an ester compound, Reacting one or more component (s) with a reaction mixture comprising an acidic catalyst, wherein at least one component forms an ester compound having no β-hydroxy group or forms an amide compound at least with the acidic catalyst The neutralization method of the acidic (trans) esterification catalyst used as a catalyst. The method of claim 16, At least one component is selected from the group consisting of an oxetane component or a derivative, an ortho-ester component, an alcohol component or a mixture of two or more thereof. A powdery coating composition comprising an ester of (meth) acrylic acid and a photoinitiator or peroxide obtained according to any one of claims 1 to 18. The method of claim 21, Wherein said composition comprises a mixture of an ester of amorphous (meth) acrylic acid and an ester of crystalline and / or semicrystalline (meth) acrylic acid. The method of claim 21 or 22, Wherein said composition comprises a photoinitiator and is UV-curable. 19. A wet coating composition comprising an ester of (meth) acrylic acid and a photoinitiator or reactive diluent obtained according to the method of any one of claims 1-18. A composite resin comprising an ester of (meth) acrylic acid and a peroxide or reactive diluent obtained according to any one of claims 1 to 18.