ES2610432B2 - Very active aluminum catalysts in ROP of glycidyl methacrylate - Google Patents

Abstract

Very active aluminum catalysts in ROP of glycidyl methacrylate. The present invention consists of an improved process for ring opening polymerization of the oxirane group of glycidyl methacrylate. Specifically, it concerns the synthesis of aluminum compounds of type (3) and the applications that these compounds have as catalysts in the ROP polymerization of glycidyl methacrylate in the absence of initiators or cocatalysts at room temperature and in short periods of time.

Description

S

VERY ACTIVE ALUMINUM CATALYSTS IN ROP DE GLlCIDL METACRYLATE SECTOR OF THE TECHNIQUE The present invention falls within the chemical sector, in the subsector of organometallic and polymer chemistry, and its application, within the field of electronics, for the preparation of electronic components.

10 15

STATE OF THE TECHNIQUE Glycidyl methacrylate is a functionalized monomer that is of great interest, as it has two reactive groups, one is a vinyl group and the other is an oxirane group. Ring opening polymerization of 10 oxirane groups allows polyether formation with pendant vinyl substituents. The most frequent use of this polymer is as a photocurable material with optimal characteristics for use in electronic devices (N. Bicak, Polym. Bull. 2006, 56, 87; N. Bicak, Eur. Polym. J. 2007, 44, 106) .

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In the literature there are few examples of glycidyl methacrylate ring opening polymerization and polymerization conditions require high temperatures, long periods of time or the presence of initiators. Thus, for example, zinc succinate catalyst has been used as a yield of 69.0% by heating 60 h at 90 ° C (N. Bicak, Polym. Bull. 2006, 56, 87).

25

Another type of catalyst that has been used for the ring opening polymerization processes of glycidyl methacrylate is trimethylsilyl triflate. With this type of catalyst a yield of 45.0% has been obtained after 240 h at room temperature and without initiator (N. Bicak, Eur. Polym. J. 2007, 44, 106).

30

In addition to the polymerization of glycidyl methacrylate, the copolymerization processes of this monomer have also aroused interest. For this purpose, in December 2007, in US patent 2007/0299242 A1 of T. Faecke, the ring opening copolymerization of propylene oxide and glycidyl methacrylate with polyethylene glycol is described using as a catalyst a heterobimetallic compound with cyanide ligands, where a metal can ~ r ~~~ M ~~~, ~~~~~~~~~~~

Cu + 2 or Cr + 3 and the other metal can be Fe + 2, Co.2, Ca · 3, Cr + 2, Cr + 3, Mn + 2, Mn + 3, 1st "3, Ni + 2, Rh +3, Ru + 2, and + 4 or y + 5, To carry out said copolymerization the catalyst with phenothiazine is previously activated by heating at 120 ° C and then, it is copolymerized at 100 ° C for 30 minutes.

Another example described is copolymerization with C02. thus it has been achieved on the one hand to obtain the insertion of C02 into the oxirane ring, with a 92.0% yield, using as a catalyst a mixture of MgBr2 and triphenylphosphine, at room temperature with a CO pressure of 6.3 MPa (JJ Shim, Chem. Cal. Chem. 2013, 5, 1344-1349). On the other hand, polycarbonate formation has been achieved using as a catalyst a heteromethalic compound of Zn and Co (II) with cyanide ligands by adding 4-meloxiphenol to inhibit the polymerization of vinyl groups. The copolymerization process is carried out at 50 oC and 4 MPa of CO pressure, lasting 13 h (X. H. Zhang, RSC Adv., 2014, 4, 3188-3194).

Although in these studies different metals have been used as catalysts, such as Mg, Zn or Co, it is found in the literature that aluminum compounds are efficient catalysts in ring opening polymerization processes of cyclic monomers (A L. Brocas, Progress in Polymer Science, 2013, 38, 845-873; ME

G. Mosquera, Organometalfics, 2008, 27, 2300-2305). In particular, an aluminum catalyst has been described for the polymerization of glycidyl methacrylate, in particular, tris (isobutyl) aluminum is used in a monomer concentration of 1.5 M in toluene. At room temperature after 24 h, no polymer is formed, however, by adding tetraoctylammonium bromide as an initiator, a 100% yield is achieved after 2 h (S. Car1otli, Macromo / ecules, 2011, 44, 6356-6364).

There are no examples of aluminum catalysts that at room temperature without the help of an initiator polymerize the glycidyl methacrylate by ring opening.

DESCRIPTION OF THE INVENTION The present invention deals with the synthesis of aluminum aryloxide compounds and their application in polymerization processes by opening glycidyl methacrylate ring.

In a first aspect, the present invention relates to the synthesis of the catalysts.

An example of general synthesis expandable to any of them is described below.

The general procedure set out in scheme 1. consists in the reaction of a phenol of type (1) with an aluminum compound of type (2), all dissolved in a non-polar solvent such as toluene. After ten minutes of reaction at -78 ° C and subsequently allowing the reaction mixture to reach room temperature, a

type aluminum compound (3).

OH

C0. ' ,

R''7.'UI fLNJ R2 + IAlRyX (3-y ~ n

'l.,

-

.Y'

R 'R'

R '

.......... AIRtY · l r (3-Y) O

and

¡XR

, X "

R '

R '

n

10 Scheme 1. Synthesis of compound 3

The synthesis reaction of these compounds is essential in an inert atmosphere. The preparation and characterization of derivatives of type (1) has already been described by D.J. Mindiola et al. In US patent 2014/0213805 A1, July 31

15 2014.

For (1) Y (3): R 'and R2 may be H, alkyl, haloalkyl, alkoxide, haloalkoxide, dialkylamino, halodialkylamino, hydroxyalkyl or cyanide.

R3 may be H, alkyl, haloalkyl, cyanoalkyl, alkoxide, dialkylamino or cyanide.

For (2) Y (3): X can be a halide. R may be H, alkyl, alkenyl, alkynyl, aryl or alkoxide.

The complexes referred to in this invention may have different isomers or may be solvated or in the form of salts.

The term "alkyl" refers to linear or cyclic carbon groups from 3 carbon atoms, which may or may not be branched. Examples of unbranched and linear alkyls are methyl, ethyl, propyl, pentyl, hexyl, heptyl. Examples of branched linear alkyls are 2-propyl, 2-butyl. Cyclic groups include cyclopropyl, cyclobutyl or cyclohexyl, among others.

The term "alkenyl · or" alkynyl ~ refers to groups with definition similar to that used for alkyl groups, but having one or more double or triple bonds C = C, CEe, respectively. They may or may not be branched and may be linear or cyclic from 3 carbon atoms. They may or may not be substituted analogously to the alkyl groups.

The term qarilon refers to aromatic groups such as phenyl, naphthyl, anthracenyl.

The term "haloalkyl" refers to alkyl groups with one or more halide substituents.

The term "alkoxide ~" refers to groups of the -O-alkyl type.

The term "haloalkoxide" refers to groups where the alkyl group of the alkoxide has one

or more halide substituents.

The term "dialkylamino" refers to groups of the type -N- (alkyl¡ '.

The term "halodialkylamino" refers to dialkylamino groups where the alkyl groups have one or more halide substituents.

The term "hydroxyalkyl" refers to alkyl groups with one or more hydroxyl substituents.

In the present invention, derivatives of type (3) have been synthesized and characterized. In addition, these derivatives have been used for polymerization studies of glycidyl methacrylate.

The glycidyl methacrylate ring opening polymerization processes are carried out as shown in scheme 2. It is carried out in the presence of an aluminum catalyst of type (3) appearing in scheme 1. It is used as a solvent a nonpolar medium, like toluene. The process is carried out at atmospheric pressure and room temperature.

Catalyst

n

~

5 Scheme 2. Glycidyl methacrylate ring opening polymerization process

The polymerization process described in this invention show the following advantages, with respect to those already described:

10 • Catalysts are resistant to degradation under catalysis conditions.

•

They are performed at room temperature and atmospheric pressure.

•

The use of initiators or cocatalysts is not required for the polymerization process to occur.

•

Conversions are elevated to short polymerization times.

15 • The procedure is simple, efficient and cheap, since the compound that would represent a higher cost, which is the catalyst, is used in a very low proportion.

DESCRIPTION OF THE FIGURES

Figure 1.- A general scheme of the type (3) aluminum catalysts used in these glycidyl methacrylate ring opening polymerization processes is depicted.

Figure 2.-ORTEP diagram of the solid-state structure of the dinuclear compound of type (3) [AIMe, (2,6-'Ph, C.H, O-4-tBu)] "obtained by X-ray section.

2S

Scheme 1.-Scheme of synthesis of aluminum catalysts.

Scheme 2.-Scheme of the polymerization process by opening glycidyl melacrylate ring.

MODE OF EMBODIMENT Two examples of catalyst synthesis and one of the catalytic processes of the invention are described in detail below.

1) Synthesis of catalysts, compounds 3.1 and 3.2.

Compound 3. 1:

On a solution of 0.50 9 (1.04 mmol) of 2,6-bis (diphenylmethyl) -4-tert-butylphenol in 10 mL of toluene in a schlenk under argon and in a cold bath at -78 oC, a solution of 0.52 mL (0.52 mmol) of [Al Me,], in 10 mL of toluene is added. The reaction mixture is maintained at -78 ° C for 15 minutes to obtain an orange solution and subsequently allowed to slowly reach room temperature. Once the room temperature is reached, the solution is completely evaporated to obtain a light orange solid that is identified as compound 3.1, which is weighed, obtaining a yield of 97.7% (0.545 9, 0.51 mmol). To obtain a single crystal of this compound, the experiment is performed as described above until room temperature is reached. Subsequently, the solution is concentrated until leaving 4 mL, precipitating a solid that, by subsequent gentle heating, dissolves obtaining an orange solution which is allowed to stand until it reaches, again, the room temperature and, finally, it is allowed to stand twenty days at -20 oC.

Anal. Calc. (%) For AI, C "H" D, (1076.72 g / mol): C, 84.77; H, 7.24. Exp .: C, 84.42; H, 6.56.

NMR data of 'H (400 MHz, 293 K, CD): O-0.66 (s, 6H, AICH,), 0.94 (s, 9H, C (CH,),), 6.71 (s, 2H, CH), 6.98-7.33 (Ph + m-DAr-H).

13C NMR data (100.6 MHz, 293 K, CD,): ~ -5.36 (s, AICH,), 31.06 (s, C (CH,),), 34.33 (s, C (CH,),), 49.67 (s, CH), 125.71-132.24 (Ph + m-DAr), 134.82-152.86 (Quaternary C).

The structure of the compound has been characterized by X-ray diffraction. Table 1. Crystallographic data of the compound 3.1.

Fact

3.1 · 3C, H,

Formula

AI2C97H1020 2

Molecular weight

1353.80

Colorlfonna

Colorless / block

Glass dimensions (mm))

0.47 x 0.45 x 0.40

Crystalline System

Monoclinic

Space group

P21 / c

aJb / c (A)

21,247 (8) / 15,293 (6V 25,193 (8)

a / (J / Y (0)

90 / 99.64 (3) 190

GOES')

8071 (5)

Z

pc «lculada (g / cm3)

1,120

11 (mm - ') / F (OOO)

0,085 / 2932

Range of 9, (0)

3.05-25.71

no. of collected reflections

no. independent reflections I Rlnt

15320 / 0.3170

no. data / restriction / params

15320/0/904

R1 / wR2 (1) 20 (1))

0.0977 / 0.2152

R1 / wR2 (all data)

0.1896 / 0.2760

GOF (enP)

1,066

Difference between peak / hole (e A-3)

0.379 / -0.413

Compound 3.2:

On a solution of 0.50 9 (1.04 mmol) of 2,6-bis (diphenylmethyl) -4-tert-butylphenol in 10 ml of toluene inside a schlenk under argon and in a cold bath at -78 " e, a solution of 1.04 mL (0.52 mmol) of [AICIMe,], in 10 mL of loluene is added.The reaction mixture is maintained at -78 ° C for 15 minutes to obtain an orange solution and subsequently , let the room temperature slowly reach After half an hour of stirring at room temperature the green solution evaporates

completely, precipitating a green solid that is identified as compound 3.2, which is weighed, obtaining a yield of 79.2% (0.46 g, 0.82 mmol).

Anal. Cale. ('lo) for AIC ", H" OCI (558.80g / mol): C, 79.52; H, 6.44. Exp .: C, 78.74; H, 6.07. 5 NMR data of 'H (400 MHz, 293 K, CD,): O-1.42 (s, 3H, AICH3), 0.92 (s, 9H, C (CH,) 3), 6.97 (s, 2H, CH), 6.98-7.54 (Ph + m-OAr-H).

NMR data of "c (100.6 MHz, 293 K, CD,): O-9.44 (s, AICH3), 30.89 (s, C (Cfh),), 34.40 (s, C (CH3) 3), 49.71 (s, CH), 125.70-130.69 (Ph + m-OAr), 134.90-151, 32 (C 10 quaternary).

2) Glycidyl methacrylate ring opening polymerization.

In a vial provided with magnetic stirrer, 16 rng (0.028) are added in the following order

15 mmol) of catalyst 3.2 which are dissolved in 1.9 rnL of toluene and 0.38 mL of the glycidyl methacrylate monomer (2,786 rnmol). The reaction is maintained at room temperature for 30 minutes. The polymerization process is stopped by adding 10 rnL of hexane. The polymer obtained is filtered, washed with distilled water and dried under vacuum by heating at 70 ° C overnight. A yield of 90.4% (0.358 g, 2.518 mmol) is obtained with

20 with respect to the starting monomer.

TNDUSTRIAL APPLICATION As for the industrial sector, the benefits derived from this patent would find applicability in the electronics industry in the preparation of electronic components.

Claims (8)

1. An aluminum complex characterized by the following formula (3): / AIRy., X¡3 · Y) OR Ih \ ~ \ "'"  I ~ · :: r'-R ' R 'U \  'one.., -"'"  ~ VR ' R ' R n Where: R1 R2 i. And they can be H, alkyl, haloalkyl, alkoxide, haloalkoxide, dialkylamino, halodialkylamino, hydroxyalkyl or cyanide. 10 ii. R3 may be H, alkyl, haloalkyl, cyanoalkyl, alkoxide, dialkylamino or cyanide. Ii. R can be H, alkyl. alkenyl, alkynyl. arila or alkoxide. V. n can be 1 or 2. v. and it can be 3. 2 01.

2.

Use of the compounds of formmu 3, according to claim 1. as catalysts in the glycidyl methacrylate ring opening polymerization process.

3.

Glycidyl methacrylate ring opening polymerization procedure

20 characterized in that it comprises carrying out the polymerization in a vial. in the presence only of the solvent, of the monomer and of a catalyst consisting of an aluminum compound of formula 3 defined in claim 1. 4. Polymerization process according to claim 3, characterized in that the polymerizing product is glycidyl methacrylate of the formula: or or

5.

Polymerization procedure according to claim 3, characterized in that

The amount of catalyst used is 1%.

s

6.

Polymerization process according to claim 3, characterized by the

use of apalar or aprotic solvents.

7.

Polymerization process according to claim 3, characterized in that

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The polymerization temperature is room temperature.

8.

Polymerization process according to claim 3, characterized by the

absence of initiators or cocatalysts.