WO2007018455A1

WO2007018455A1 - Process for allylation of mixed polyhydric compounds

Info

Publication number: WO2007018455A1
Application number: PCT/SE2006/000831
Authority: WO
Inventors: Göran BERGVALL
Original assignee: Perstorp Specialty Chemicals Ab
Priority date: 2005-08-11
Filing date: 2006-07-04
Publication date: 2007-02-15
Also published as: SE528588C2; SE0501802L

Abstract

Disclosed is a process for allylation of mixed polyhydric compounds comprising at least two different polyhydric compounds each having at least 3 hydroxyl groups. The process comprises that that at least one polyhydric compound (II) having a melting point of less than 120°C is used as solution medium and/or as a carrier for at least one polyhydric compound (I) having a melting point of at least 15O0C and that said polyhydric compound (I) and said polyhydric compound (II) in a molar ratio of between 1 :3 and 3: 1 are subjected to allylation at a temperature of 100-16O0C, by reaction with at least one allylic and/or methallylic compound.

Description

PROCESS FOR ALLYLATION OF MIXED POLYHYDRIC COMPOUNDS

The present invention refers to a process for allylation of mixed polyhydric compounds. Said process comprises that a mixture of at least one polyhydric compound having a melting point of less than 120°C and at least one polyhydric compound having a melting point of at least 160⁰C is subjected to allylation yielding mixed allyl ethers of said polyhydric compounds. In further aspect the present invention refers to the use of a mixed allyl ether obtained by said process.

Allyl ethers are in this context reaction products between polyhydric compounds, such as polyalcohols, and one or more allyl or methallyl halides or alcohols yielding ethers having one or more allyl and/or methallyl groups.

It is well known in the art that allyl and methallyl ethers, such as trimethylolpropane and pentaerythritol allyl and methallyl ethers are used in preparation of direct gloss unsaturated polyesters without air inhibition. The here most frequently used allyl and methallyl ethers are those based on trimethylolpropane as they are easy to synthesise due to the good solubility of trimethylolpropane in the reaction media. It is furthermore well known to those skilled in the art that the efficiency and reactivity of such unsaturated polyester systems depend on the allyl or methallyl functionality of used allyl or methallyl ether and that the efficiency is improved by allyl or methallyl groups as end groups in the polyester chain rather than in side position along the chain. The efficiency and reactivity increase with increased allyl or methallyl functionality such that triallyl and methallyl ethers are more reactive than diallyl and methallyl ethers which are more reactive than monoallyl and methallyl ethers.

A major drawback in obtaining increased allyl and/or methallyl functionality is that higher functional polyhydric alcohols, such as pentaerythritol, typically due to high melting points and low solubility in most reaction media are difficult to allylate by reactions with allyl or methallyl halides and/or allyl or methallyl alcohols. An approach to overcome said drawback is been the use inert solvents, such as aromatic or aliphatic solvents, to dissolve/ disperse the polyhydric material. This approach have serious disadvantages, such as the need to remove the inert solvent in a separate process step. Inorganic solvents are normally and typically not used in allyl ether applications.

The present invention quite unexpectedly provides a new and improved process for allylation of polyhydric compounds having high melting points and/or low solubility in typically used reaction media. The process of the present invention refers to solvent free process for allylation of mixed polyhydric compounds of which at least one polyhydric compound has a melting point of at least 15O⁰C, such as at least 16O⁰C, and that at least one polyhydric compound (H) has a melting point of less than 120°C, such as less than HO⁰C or less than 100⁰C. Said polyhydric compound (II) is used as solution medium and/or as a carrier for said polyhydric compound (I). Said polyhydric compounds are subjected to allylation at temperature of for instance 100-160⁰C, by reaction with at least one allylic and/or methallylic compound yielding allyl ethers of said polyhydric compounds. A suitable ratio between said polyhydric compound (I) and said polyhydric compound (II) is found at a molar ration of between 1 :3 and 3:1, such as between 2:1 and 1:2. Said polyhydric compound (I) can be charged in a single step or in two or more subsequent steps.

Said polyhydric compound (I) is in preferred embodiments of the present invention a 2-alkyl-2-hydroxyalkyl-l,3-propanediol, a 2,2-dihydroxyalkyl-l,3-propanediol and/or a dimer, trimer or polymer of a said 1,3 -propanediol having said melting point. Said polyhydric compound (I) is in its most preferred embodiments trimethylolethane, di-trimethylolethane, pentaerythritol, di-pentaerythritol, tri-pentaerythritol and/or combinations thereof. Further embodiments of said polyhydric compound (I) include dendritic polyester and polyether polyols having said melting point.

Said polyhydric compound (H) is in likewise preferred embodiments of the present invention a 2-alkyl-2-hydroxyalkyl-l,3-propanediol, a 2,2-dihydroxyalkyl-l,3-propanediol and/or a dimer, trimer or polymer of a said 1,3-propanediol having said melting point. Said polyhydric compound (II) is suitably exemplified by trimethylolpropane and di-trimethylolpropane. Further suitable and preferred polyhydric compounds (II) are for instance glycerol, di-glycerol and dendritic polyester and/or polyether polyols having said melting point.

Suitable dendritic polyester and/or polyether polyols for use as polyhydric compound (I) or polyhydric compound (II) are disclosed in for instance the International Patent Applications WO 93/17060, WO 93/18079, WO 96/07688, WO 96/12754, WO 99/00439, WO 99/00440, WO 00/56802 and WO 02/40572, which by reference are herein included.

Said dendritic polyester and/or polyether polyols are most preferably obtained by addition of at least one di, tri or polyhydric monocarboxylic acid to a di, tri or polyhydric core molecule at a molar ratio yielding a polyhydric dendritic polymer comprising a core molecule and at least one branching generation bonded to said di, tri or polyhydric core molecule or are obtained by ring opening addition of at least one oxetane of a di, tri or polyhydric compound to a di, tri or polyhydric core molecule at a molar ratio yielding a polyhydric dendritic polymer comprising a core molecule and at least one branching generation bonded to said di, tri or polyhydric core molecule. The use of dihydric compounds, such as glycols, and monohydric compounds as polyhydric compound (H) is of course possible. These products will, however, reduce allyl and/or methallyl functionality and lead to formation of allyl and/or methallyl ethers, such as diallyl or dimethallyl ethers of glycols, which are negative or undesired in allyl and/or methallyl ether applications.

Combinations of two or more polyhydric compounds (I) and/or (H) as disclosed above are of course possible and in certain cases even favourable from for instance a technical point of view.

Said at least one allylic and/or methallylic compound is preferably at least one allyl or methallyl halide, such as allyl and/or methallyl chloride and/or bromide, and/or at least one allyl or methallyl alcohol.

Said allylation is in especially preferred embodiments of the process according to the present invention performed at a molar ratio hydroxyl groups to allyl or methallyl groups of between 1:0.5 and 1:1.

In the most preferred embodiments of the present process, said polyhydric compound (I) is pentaerythritol or di-pentaerythritol, said polyhydric compound (II) is trimethylolpropane or di-trimethylolpropane, and said allyl or methallyl halide is allyl and/or methallyl chloride.

The process of the present invention is preferably performed in the presence of a catalytic material, such as at least one alkali metal hydroxide and/or a metal cyanide and/or in the presence of at least one allyl and/or methallyl ether as allylation initiator. Said alkali metal hydroxide is preferably potassium and/or sodium hydroxide and said allylation initiator is likewise preferably at least one allyl and/or methallyl ether of at least one 2-alkyl-2-hydroxyalkyl-l,3-propanediol, a 2,2-dihydroxyalkyl-l,3-propanediol and/or at least one dimer, trimer or polymer of a said 1,3 -propanediol. Suitable allylation initiators can be exemplified by allyl and/or methallyl ethers of glycerol, trimethylolethane, trimethylolpropane, di-trimethylolethane, di-trimethylolpropane, pentaerythritol, di-pentaerythritol and/or tri-pentaerythritol.

The process of the invention discloses that it is possible to dissolve large parts of for instance pentaerythritol in triols such as trimethylolpropane. Weight ratios between for instance 2:1 and 3:1 are possible. Said weight ratios can using allyl chloride as allyl compound yield a mixed allyl ether having an allyl functionality of between 2.5 and 2.8 within a process time, such as 4-6 hours, similar as the process time for pure trimethylolpropane and allyl chloride while the process time for pure pentaerythritol and allyl chloride typically is in the range 16-20 hours. This enables production of higher functional allyl compounds at a reduced process time. Evaluation of such allyl ethers shows that for instance unsaturated polyesters exhibit significantly higher reactivity than comparable unsaturated polyesters based on the frequently used trimethylolpropane diallyl ether and close to those based on pentaerythritol triallyl ether. This can be used either to produce for instance unsaturated polyesters with a higher reactivity or a lower content of allyl functional ethers. Another possibility is to formulate to use less styrene which is generally desired from an environmental point of view.

In a further aspect the present invention refers to the use of a mixed allyl ether, obtainable by the process of the present invention, as raw material and/or intermediate product in production of monomers, oligomers or polymers having at least one allyl or methallyl group, such as unsaturated esters and polyesters for use in for instance protective and/or decorative paint, lacquer, ink or glue compositions. Said compositions include radiation, such as UV, curing compositions.

In yet further aspects, the present invention refers to the use of a mixed allyl ether, obtainable by the process of the present invention, as crosslinker for acrylic polymers in acrylic thickeners and in superabsorbant polymers.

The mixed allyl ether obtainable by the process of the present invention can, furthermore, suitably be used as raw material and/or intermediate product in production of putties, fillers and electric and/or electronic insulation materials.

Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilise the present invention to its fullest extent. The following preferred specific embodiments are, therefore, to be construed as merely illustrative and not limitative of the remainder of the disclosure in any way whatsoever. In the following Example 1 refers synthesis of a mixed allyl ether in accordance with an embodiment of the present invention and Examples 2 and 3 refer to evaluation in an unsaturated polyester of the product obtained in Example 1.

Example 1

67.4 g of trimethylolpropane, 68.3 g of pentaerythritol, 80 g of NaOH and as allylation initiators 6.8 g of trimethylolpropane diallyl ether and 6.8 g of pentaerythritol triallyl ether were charged in a laboratory autoclave equipped with a heating device, a stirrer, a water separator and a reflux condenser. The mixture was heated to 115⁰C. 200 g of a 50% aq. NaOH solution and 216.4 g of allyl chloride (99%) was gradually charged at said temperature (charging time NaOH - 4 hours, allyl chloride - 6 hours). The temperature was kept at 115°C and the charging of allyl chloride was adjusted to maintain an adequate reflux. Reaction water was continuously azeotropically separated. The reaction mixture was, following said charging, stirred at 115⁰C for additional 2 hours. The reaction mixture was now cooled to 9O⁰C and 500 g of water was added to dissolve formed salt. The organic phase was neutralised with NaOH to a pH of 6.5 and washed with water. The organic phase was finally evaporated under vacuum.

Obtained product was analysed with the following result:

Allylation degree 2.6

Low boiling compounds 0.4%

Trimethylolpropane monoallyl ether 0.5%

Trimethylolpropane diallyl ether 42.5%

Trimethylolpropane triallyl ether 9.6%

Pentaerythritol diallyl ether 2.4%

Pentaerythritol triallyl ether 36.5%

Pentaerythritol tretraallyl ether 7.4%

High boiling compounds 0.7%

Example 2

An unsaturated polyester comprising the mixed allyl ether obtained in Example 1 was prepared and compared with unsaturated polyester prepared from trimethylolpropane diallyl ether and a mixture of trimethylolpropane diallyl ether and pentaerythritol triallyl ether. Below raw materials and amounts in grams were charged in a laboratory autoclave equipped with a heating device, a stirrer, nitrogen purge, a Dean-Stark separator, an intermediate cooler and a condenser and esterified at 185°C in accordance with a standard process for preparation of unsaturated polyesters.

*1: TMPDE 80, Perstorp Specialty Chemicals AB, Sweden. *2: Perstorp Specialty Chemicals AB, Sweden. The following characteristics were obtained:

Example 3

Lacquers were prepared by diluting the unsaturated polyesters obtained in Example 2 to 65% in butylacetate and subsequently admixing 0.18 g of flow agent (EFKlA 35), 0.75 g of Cobalt octoate (10% Co) and 0.50 g of methylethyl ketone peroxide (45%) into 50 g of said diluted polyesters.

Prepared lacquers were applied on glass panels and the drying time and pendulum hardness as Kδnig seconds were recorded. The result is given in below table.

Claims

1. A process for allylation of mixed polyhydric compounds comprising at least two different polyhydric compounds each having at least 3 hydroxyl groups characterised in, that at least one polyhydric compound (I) has a melting point of at least 150°C, such as at least 160⁰C, that at least one polyhydric compound (II) has a melting point of less than 120⁰C, such as less than 110⁰C or less than 100⁰C, that said polyhydric compound (H) is used as solution medium and/or as a carrier for said polyhydric compound (I), that said polyhydric compound (I) and said polyhydric compound (II) in a molar ratio of between 1:3 and 3:1, such as between 2:1 and 1:2, are subjected to allylation at a temperature of 100-160⁰C, by reaction with at least one allylic and/or methallylic compound yielding allyl ethers of said polyhydric compounds.

2. A process according to Claim 1 c harac t eri s e d i n, that said polyhydric compound (I) is a 2-alkyl-2-hydroxyalkyl-l,3-propanediol, a 2,2-dihydroxyalkyl- -1,3-propanediol and/or a dimer, trimer or polymer of a said 1,3-propanediol.

3. A process according to Claim I or2 characterised in, that said polyhydric compound (T) is trimethylolethane, di-trimethylolethane, pentaerythritol, di-pentaerythritol or tri-pentaerythritol.

4. A process according to Claim 1 charac t eri s e d i n, that said polyhydric compound (T) is a dendritic polyester and/or polyether polyol.

5. A process according to any of the Claims 1-4 charact eris ed in, that said polyhydric compound (II) is a 2-alkyl-2-hydroxyalkyl-l,3-propanediol, a 2,2-dihydroxyalkyl- 1,3-propanediol and/or a dimer, trimer or polymer of a said 1,3-propanediol.

6. A process according to any of the Claims 1-5 characteris ed in, that said polyhydric compound (TT) is glycerol, trimethylolpropane or di-trimethylolpropane.

7. A process according to Claim 1 charact eri s e d in, that said polyhydric compound (H) is a dendritic polyester and/or polyether polyol.

8. A process according to any of the Claims 1-7 characterised in, that said allylic and/or methallylic compound is at least one allyl or methallyl halide and/or at least one allyl or methallyl alcohol.

9. A process according to Claim 8 characterised in, that said allyl or methallyl halide is allyl and/or methallyl chloride and/or bromide.

10. A process according to any of the Claims 1-9 characteri s ed in, that said allylation is performed at a molar ratio hydroxyl groups to allyl or methallyl groups of between 1:0.5 and 1:1.

11. A process according to any of the Claims 1-10 characteri sed in, that said polyhydric compound (I) is pentaerythritol or di-pentaerythritol that said polyhydric compound (II) is trimethylolpropane or di-trimethylolpropane, and that said allyl or methallyl halide is allyl and/or methallyl chloride.

12. A process according to any of the Claims 1-11 characterised in, that said allylation is performed in presence of at least one catalytic agent.

13. A process according to Claim 12 characterised in, that said catalytic agent is at least one alkali metal hydroxide, such as potassium and or sodium hydroxide.

14. A process according to Claim 12 characterised in, that said catalytic agent is at least one metal cyanide.

15. A process according to any of the Claims 1-14 characterised in, that at least one allyl and/or methallyl ether is present as allylation initiator.

16. A process according to Claim 15 characterised in, that said at least one allyl and/or methallyl ether is at least one allyl and/or methallyl ether of at least one 2-alkyl-2-hydroxyalkyl- 1,3 -propanediol, a 2,2-dihydroxyalkyl-l,3-propanediol and/or at least one dimer, trimer or polymer of a said 1,3-propanediol

17. A process according to Claim 15 or 16 characterised in, that said at least one allyl and/or methallyl ether is at least one allyl and/or methallyl ether of glycerol, trimethylolethane, trimethylolpropane, di-trimethylolethane, di-trimethylolpropane, pentaerythritol, di-pentaerythritol and/or tri-pentaerythritol.

18. A process according to any of the Claims 1-17 characterised in, that said polyhydric compound (I) is charged in a single step or in two or more subsequent steps.

19. Use of a mixed allyl ether obtainable according to any of the Claims 1-18, as raw material and/or intermediate product in production of a monomer, oligomer or polymer having at least one allyl or methallyl group.

20. Use according to Claims 19, wherein said monomer, oligomer or polymer is an unsaturated ester or polyester.

21. Use according to Claims 19 or 20, wherein said monomer, oligomer or polymer is included in a composition for protective and/or decorative paints or lacquers, inks or glues.

22. Use according to Claim 21, wherein said composition is a radiation curing composition.

23. Use according to Claim 22, wherein said radiation curing composition is a UV curing composition.

24. Use of a mixed allyl ether obtainable according to any of the Claims 1-18, as crosslinker for acrylic polymers in acrylic thickeners.

25. Use of a mixed allyl ether obtainable according to any of the Claims 1-18, in superabsorbant polymers.

26. Use of a mixed allyl ether obtainable according to any of the Claims 1-18, as raw material and/or intermediate product in production of putties and fillers.

27. Use of a mixed allyl ether obtainable according to any of the Claims 1-18, as raw material and/or intermediate product in production of electric and/or electronic insulation materials.