Claims
- 1. A method for the synthesis of polymethacrylate ester of the general formula ##STR10## wherein R.sup.1 are the same or different and represent alkyl groups with 1 to 8 carbon atoms,
- R.sup.2 represents a group derived from an alcohol R.sup.2 OH, wherein R.sup.2 is a C.sub.2 -C.sub.30 alkyl group, an --R.sup.4 OH group, wherein R.sup.4 is a divalent aliphatic carbon group with 2 to 20 carbon atoms, or a --(CH.sub.n H.sub.2n O--) R.sup.5 group, wherein R.sup.5 is a hydrogen, alkyl or an alkaryl group,
- n is a number from 2 to 18 and b is a number not less than 1,
- G represents the R.sup.1 groups or R.sup.2 groups,
- R.sup.3 represents the group of a known chain regulator, the R.sup.3 group being free of active hydrogen atoms, and
- a is a number which, on the average, is not less than 4,
- with the proviso that the boiling point of the R.sup.2 OH alcohol is higher than that of the R.sup.1 OH alcohol, comprising
- transesterifying a polymethacrylate ester of the general formula ##STR11## obtained by free radical polymerization in presence of a chain-length regulator and wherein the R.sup.1 and R.sup.3 groups and the subscript a have the meanings already given, with alcohols of the formula R.sup.2 OH at a temperature of about between 70.degree. and 150.degree. C., optionally in the presence of a solvent with the addition of non-basic transesterification catalysts in a molar ratio of polymethacrylate ester to R.sup.2 OH of 1:1 to 1:5.
- 2. The method of claim 1, comprising that the transesterification is carried out in a molar ratio of polymethacrylate ester to R.sup.2 OH of 1:1 to 1:2.
- 3. The method of claims 1 or 2, comprising that alkyl titanate, alkyl zirconate, dialkyl tin acetate halide or dialkyl tin dialkyl ester is used as transesterification catalyst in an amount of about between 0.1 and 2% by weight, based on the polymethacrylate ester.
Priority Claims (1)
Number |
Date |
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43 06 537.6 |
Mar 1993 |
DEX |
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Parent Case Info
This is a divisional application of Ser. No. 08/501,591, filed Jul. 12, 1995, which in turn is a continuation application of Ser. No. 08/187,978, filed Jan. 28, 1994, abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
5115040 |
Fock et al. |
May 1992 |
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5133898 |
Fock et al. |
Jul 1992 |
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5338445 |
Fock et al. |
Aug 1994 |
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Divisions (1)
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Number |
Date |
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Parent |
501591 |
Jul 1995 |
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Continuations (1)
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Number |
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187978 |
Jan 1994 |
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