Polyesters containing (meth)acrylate end groups

Details Polyesters containing (meth)acrylate end groups Polyesters containing (meth)acrylate end groups

2002-01-14

2003-08-05

Acquah, Samuel A. (Department: 1711)

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Mixing of two or more solid polymers; mixing of solid...

C528S361000, C525S444000, C424S422000, C424S424000, C424S426000, C424S443000, C424S484000

Reexamination Certificate

active

06602963

ABSTRACT:

The invention relates to polyesters containing (meth)acrylate groups as defined by the formula (I) CH
2
═CRCOO—PE—OCOCR═CH
2
wherein R and PE are as defined herein.
Methacrylic acid esters of polyhydric alcohols are extensively used in industry as crosslinking monomer building blocks. In order to cover the widest possible variety of industrial requirements, virtually all alkanediols available industrially have in this connection been converted into the corresponding methacrylic acid esters, and likewise a large number of ethylene glycols and propylene glycols are also available as methacrylic acid esters, for example diethylene glycol dimethacrylate or polypropylene glycol dimethacrylate.
By contrast, polyesterdiols containing methacrylate end groups or acrylate end groups (generally: (meth)acrylate end groups) play only a secondary role. Whereas polyesterdiols are of considerable importance as soft segments for building up polyurethanes, the corresponding polyesterdiols containing (meth)acrylate end groups have no significant importance. This is all the more amazing since these polyesters are generally readily available and have a good plasticiser action, good optical properties and good weathering resistance. This misunderstanding is attributable primarily to the classical synthetic routes for (meth)acrylic acid esters. Thus, the synthesis of (meth)acrylic acid esters starting from alcohol and (meth)-acryloyl chloride plays only a secondary role, in particular due to the necessity for binding the liberated HCl and owing to the formation of chlorine-containing by-products.
The (meth)acrylic acid esters are primarily formed by direct esterification of the corresponding alcohols with methacrylic acid or acrylic acid or in particular by transesterification of the alcohols with methyl methacrylate or methyl acrylate with the aid of a basic or organotin catalyst (see, for example, DD 272067 or EP 663 386). In this esterification, the polyester is of course also transesterified, at least partially, the consequence that considerable isomerisation of the polyester takes place. By contrast, the &agr;,&ohgr;-hydroxyl groups of the polyesterdiols react selectively and rapidly with isocyanates, which means that they can readily be used for building up polyurethanes. In this way, for example by reaction with isocyanatoethyl methacrylate or by reaction with a diisocyanate followed by reaction with hydroxyethyl methacrylate, polyesterurethane methacrylates are obtainable in a simple manner (see J. M. S.-Rev. Macromol. Chem. Phys., C33 (2)m 147-180 (1993), Current Status of Urethane (Meth)acrylate Oligomers and Polymers).
The reaction of polyesters containing carboxyl end groups with glycidyl methacrylate proceeds with similar selectivity, in this case giving polyesters containing methacrylate end groups, but also hydroxyl groups.
The direct introduction of the methacryloyl group, for example in the course of living polymerisation for the synthesis of polymers containing &agr;,&ohgr;-dimethacrylate groups, has also been described. Thus, Heitz et al. (U.S. Pat. No. 4,412,063) produces a polytetrahydrofuran containing methacrylate end groups by cationic polymerisation in the presence of methacrylic anhydride.
Kataoka et al. (U.S. Pat. No. 5,929,177) describe the build-up of a block copolymer X—O—(—CH
2
—CH
2
—O—)
m
—(Y)
n
—Z by living polymerisation starting from a polyvalent, functional, for example amino group-containing central group X, where firstly a polyethylene oxide block, then a polymethacrylate or polyester block Y is produced and finally a methacryloyl group is introduced by termination using, for example, methacrylic anhydride. Block copolymers of this type containing polymerisable end groups and a polar central function X are suitable, for example, for building up specific polymerisable surfactants. Polyesters containing —O—CH
2
—O— units and (meth)acrylate end groups which have particularly good biodegradability are described by Klaveness et al. (U.S. Pat. No. 5,693,321).
If a specific chain-length distribution and high end-group functionality are not important, the (meth)acrylate end groups can also be introduced directly during synthesis of the polyesters. Thus, Vyvoda (U.S. Pat. No. 5,290,852) describes the concomitant use of 2-hydroxyethyl methacrylate, methacrylic acid or methacrylic anhydride as monofunctional end groups in the synthesis of a polyester based on glutaric acid. These polyester mixtures are employed in the polymerisation of vinyl chloride for the preparation of internally plasticised PVC.
Schmitt et al. (U.S. Pat. No. 4,795,823) describe the synthesis of an &agr;, &ohgr;-methacrylate-containing polyester based on triglycolic acid and T-diol (abbreviation for a diol having a complex structure) starting from an oligoester and methacrylic acid. The oligoester containing methacrylate end groups, but also 32% of the T-diol dimethacrylate are found here. This ester/polyester mixture is employed as dental material.
A considerable proportion of short-chain alkanediol esters is also found in the direct esterification of polylactide with methacrylic acid. In addition, these polyesters obtained by direct esterification of a polylactide with methacrylic acid are intensely colored (see U.S. Pat. No. 4,731,425 and Comparative Example 1).
A particularly gentle synthesis of acrylic acid esters is described by Ayorinde et al. (U.S. Pat. No. 5,491,244), which gives access to a sensitive epoxyacrylic anhydride. This synthesis is carried out without any catalyst and with a 4-fold excess of acrylic anhydride.
By contrast, the synthesis of methacrylic acid esters starting from methacrylic anhydride and various &agr;-hydroxycarboxylic acid esters (lactic acid esters) proceeds significantly less well. In spite of catalysis with sulfuric acid, an excess of methacrylic anhydride and heating at 130° C. for 5 hours, a conversion of only about 50% is achieved. In addition, problems arise in separating off the unreacted anhydride (see Rehberg et al., Journal of the American Chemical Society, Vol 67, 210 (1945)).
There continues to be a demand for polyesters containing (meth)acrylate end groups, for example for building up low-shrinkage systems or in the area of two-component adhesives. Of particular interest are polyesters containing polymerisable (meth)acrylate end groups based on poly-&agr;-hydroxycarboxylic acids (for building up copolymers containing degradable lactide branches, see, for example, Sandner et al., Macromol. Symp. 1996, 103 (Polymer and Medicine), 149-62).
In order to ensure good biodegradability, the content of short-chain di(meth)acrylates without an ester group between the (meth)acrylate end groups should be as low as possible.
There is likewise a demand for chlorine-free, transparent, amorphous polyesters containing (meth)acrylate end groups which have the highest possible functionality and are of high optical quality and which, like the polyesterdiols of polyurethanes, are suitable as weathering-stable soft segment for building up poly(meth)acrylate systems.
There is a demand for (meth)acrylates functionalised in this way for the following specific applications in medical technology:
adhesive bonding of endogenous hard tissue, for example anatomical reposition, fixing and retention of bone fragments in comminuted fractures and joint fractures
augmentation of osteosynthesis material made from metal or plastic (screws, pins) in bones, particularly in osteoporotic bones, for improving mechanical stability
adhesive bonding of endogenous soft tissue into hard tissue, for example in the fixing of tendons and ligaments into drilled holes in bones
production of highly porous moldings for implantation in bone
production of composite materials by mixing with ceramic or salt-like substances, such as, for example, hydroxylapatite or calcium phosphates
dental material, for example also prefabricated moldings (inserts)
dental lacquer
base material for implantable active-ingredient carriers
absorbable membrane for covering bone defects
material for the production of imp

Affiliated with

Also associated with

Rating

Polyesters containing (meth)acrylate end groups does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Polyesters containing (meth)acrylate end groups, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Polyesters containing (meth)acrylate end groups will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3112210