# US 4,394,470 A · Colored polyethylene terephthalate moulding compound and moulded products made therefrom

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- Number: US 4,394,470 A
- Document ID: US4394470A
- Status: Granted
- Kind: A
- Application number: 06/359,846
- Filed: 1982-03-19
- Granted: 1983-07-19
- Earliest claimed: 1981-03-20
- Assignees: Akzo N.V.
- Inventors: Marcel A. Werner; Arnold Venema; Michael G. H. Pisters
- Web page: https://patentgrep.com/patent/US4394470A

## CPC

- C09B 61/00: Dyes of natural origin prepared from natural sources {, e.g. vegetable sources}
- C08L 67/02: Polyesters derived from dicarboxylic acids and dihydroxy compounds (C08L67/06 takes precedence)
- C09B: ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES {, e.g. PIGMENTS}; MORDANTS; LAKES (fermentation or enzyme using processes to synthesise a desired chemical compound C12P)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

A polyethylene terephthalate moulding composition is disclosed having uniformly dispersed therein 10-25,000 ppm of caramel as a colorant. The colorant is non-toxic, does not affect the transparency of the polyester, and does not cause aldehyde formation. The caramel may have been formed in situ from a mono- or disaccharide which has been added to the bis(beta-hydroxyethyl)terephthalate before or during polycondensation or to the molten polyester. The color may have been intensified by adding an alkaline reacting compound. The composition may moreover contain further colorants. The composition is particularly suitable for use in the manufacture of food containers such as boxes, trays and bottles.

## Claims

### Claim 1

A coloured polyethylene terephthalate moulding compound, characterized in that in the moulding compound there is uniformly distributed 10-25000 ppm of caramel.

### Claim 2 (depends on 1)

A moulding compound according to claim 1, characterized in that the moulding compound is transparent.

### Claim 3 (depends on 1)

A moulding compound according to claim 1, characterized in that the caramel is formed in situ from a mono- or disaccharide which has been added to the ethylene terephthalate ester before or during polycondensation thereof.

### Claim 4 (depends on 1)

A moulding compound according to claim 1, characterized in that the caramel is formed in situ from a mono- or disaccharide which has been added to molten polyethylene terephthalate.

### Claim 5 (depends on 3)

A moulding compound according to claim 3, characterized in that the amount of saccharide added is in the range of 500 to 10000 ppm.

### Claim 6 (depends on 1)

A moulding compound according to claim 1, characterized in that the caramel has been blended in the molten polyethylene terephthalate in an amount of 10 to 10000 ppm.

### Claim 7 (depends on 3)

A moulding compound according to claim 3, characterized in that the colouring has been intensified by the addition, before during or after the polycondensation of the ester, of an alkaline substance in an amount of 100 to 2500 ppm, based on the ester.

### Claim 8 (depends on 7)

A moulding compound according to claim 7, characterized in that the alkaline substance is added in an amount of 100 to 1000 ppm and is selected from the group consisting of Na-hydroxide, K-hydroxide, Na-hydrocarbonate, K-hydrocarbonate, Na-carbonate, K-carbonate.

### Claim 9 (depends on 1)

A moulding compound according to claim 1, characterized in that the moulding compound also contains one or more other colourants.

### Claim 10

A process for preparing a coloured polyethylene terephthalate moulding compound, which comprises incorporating caramel substantially uniformly in the polyethylene terephthalate, the caramel being used in an amount of 10-25000 ppm.

### Claim 11 (depends on 10)

The process of claim 10 wherein the caramel is formed in situ by mixing mono- or disaccharide with the ethylene terephthalate ester before or during polycondensation thereof.

### Claim 12 (depends on 10)

The process of claim 10 wherein the caramel is formed in situ by mixing mono- or disaccharide with molten polyethylene terephthalate.

### Claim 13 (depends on 10)

The process of claim 10 wherein caramel in an amount of 10-10000 ppm is mixed with molten polyethylene terephthalate.

### Claim 14 (depends on 11)

The process of claim 11 wherein before, during or after the polycondensation of the ethylene terephthalate ester an alkaline substance is mixed therewith in an amount of 100 to 2500 ppm, based on the ester.

### Claim 15 (depends on 14)

The process of claim 14 wherein the alkaline substance is selected from the group consisting of Na-hydroxide, K-hydroxide, Na-hydrocarbonate, K-hydrocarbonate, Na-carbonate, K-carbonate.

### Claim 16

A coloured polyethylene terephthalate container for solids or liquids, characterized in that the polyethylene terephthalate contains 10-25000 ppm of caramel.