Preparation of bromine-containing hydroxy-functional copolymers

Abstract

A bromine-containing, hydroxy-functional copolymer is prepared from an initiator that is solid at room temperature and has at least one bromine atom. The initiator is reacted with an effective amount of lactone monomers, optionally in the presence of a catalyst, to establish a bromine-containing, hydroxy-functional copolymer that is a liquid at room temperature. The copolymer of this invention may be used as liquid reactive flame retardant and, in the event the copolymer is polyfunctional, as a crosslinker.

Description

[0001] 1. Field of the Invention[0002] The invention relates to processes for the preparation of bromine-containing hydroxy-functional copolymers, and more specifically, to novel bromine-containing hydroxy-functional esters and polyesters. The invention further relates to the use of the bromine-containing hydroxy-functional copolymers, for example, for use as a reactive flame retardant and / or cross-linker, in urethane and non-urethane systems, including such materials as foams, coatings, adhesives, elastomers, paints, composites, and the like.[0003] 2. Description of the Related Art[0004] Bromine-containing compounds are commonly used for the fire retardation in various polymeric materials. Fire retardants can be applied in two forms: as non-reactive additives or as co-polymerizable reactive reactants.[0005] Generally, fire retardant additives that are non-reactive do not react with a crosslinkable polymeric matrix. Instead, the non-reactive additives are dissolved or dispersed in t...

AI Technical Summary

Benefits of technology

[0026] Accordingly, an object of the present invention is to provide a process for preparing a liquid, bromine-containing hydroxy-functional copolymer that possesses sufficiently low viscosity so that the problems described above can be reduced or overcome, while having a relatively high bromine content so that good flame retardant properties may be realized.

[0028] It is another object of the present invention to provide a process for improving the flame retardant properties of polyurethanes (e.g., foam, coating, adhesive, elastomer) and thermosetting coatings, composites, and the like.

Problems solved by technology

In addition, the presence of the dissolved or dispersed fire retardant may detract from the physical properties of the polymer matrix.

One of the main disadvantages of DBNPG for polyurethanes is its limited solubility and slow dissolution rate in many of the raw materials commonly used for the preparation of polyurethane products.

If DBNPG is not fully dissolved in the polyol components, several problems may result, such as poor physical and retardation properties as well as blockage of the lines and nozzles of polyurethane manufacturing equipment.

The limited solubility of DBNPG in various polyether and polyester polyols gives DBNPG a significant disadvantage when used in many polyurethanes (e.g., foams, coatings, adhesives, elastomers) and non- polyurethane thermosets (e.g., coatings, paints, composites).

However the disadvantage of this final product is cost.

A further disadvantage of the adipate is its tendency to form a very viscous mass due to polyester formation.

However, the high viscosity of these products prevents them from being used in all polyurethane systems.

However, the reaction between alcohol and formaldehyde is difficult to control and usually causes an undesirable increase in the viscosity of the final reactive bromine-containing alcohol.

In addition, segregation and incompatibilities can result when the resulting products are used in polyurethane systems.

However, this process leads to a darkly colored dibromobutenediol, and evolution of bromine.

However, this process produces polyols having a low content of bromine and low functionality.

These polyols find use only in hard polyurethane foams at the expense of quality.

However, the preparation of allyl ethers is a slow reaction and is difficult to control.

In addition, the subsequent bromination produces a number of side reactions producing a large number of reaction products.

However, the dark color of the final product limited its practical use in certain applications, for instance, where a clear or transparent coating is required.

Disadvantageously, the final product is dark in color and the bromination yield is very low (no content of bromine available).

However, it is expected that the very high viscosity of the copolymer precludes the use of the copolymer in a polyurethane system.

However, this process results in a mixture of bromine-containing and non-bromine-containing polyesters.

The use of high melting point initiators (such as sucrose, sorbitol and pentaerythritol), as described in many of the above patents, often results in the production of darkly colored conventional polyether polyols (non-bromine-containing polyols) due to discoloration or decomposition of the initiators.

Thus far, none on these proposals can be used effectively to provide a reactive bromine-containing flame retardant for polyurethane foams, polyurethane coatings, polyurethane adhesives, polyurethane elastomers, and thermosetting coatings and composites based on the combined criteria of high bromine content, wide applicability, low viscosity, clear color, and high compatibility with polyether polyols, polyester polyols and even epoxy resins.

But discoloration is not avoided, and together with the low bromine content of alkoxylated bromine-containing diols presents obstacles to wide commercial use in various polyurethane systems.