A dye for coloring cigarette paper

(42) Date of commencement of the patent: 15. 5.1995 (45) Date of issue: 27.12.1995 (30) Priority:

(73) Patent owner:

5th 1.1990 US 461152 claimed.

(56) Documents:

AT 200490B DE 3011044C EP 70559A2 EP 264873A2 US 2840085A

BROWN & WILLIAMSON TOBACCO CORPORATION 40232 LOUISVILLE (US).

(54) DYES FOR COLORING CIGARETTE DANDER PAPER, METHOD FOR CLEANING CARAMEL COLOR AND FILTER CIGARETTE PRODUCT (57) A dye for browning cigarette paper consists of caramel as a brown dye, a plasticizer for preventing paper whitening, and water. The dye may further contain carmine as a red colorant to alter the shade and hue of the caramel's brown color. The dye may further contain a burn additive to optionally promote the burn-off of the colored paper.

CD

AT 400 385

KR 0372033

AT 400 385 Β

The invention relates to a dye for dyeing cigarette paper containing a plasticizer for preventing the paper from becoming friable and water.

Further, the invention relates to a process for cleaning caramel color, comprising the steps of: prefiltering the caramel color extract to remove particulate matter above a predetermined size, diluting the resulting prefiltered extract, and spray-drying this retained product to provide a purified caramel powder product.

It is known to dye cigarette wrapper paper with synthetic dyes. However, acceptable, commercially available papers usually include synthetic materials which in some cases are unacceptable for taste or other reasons.

From EP-A2-264 873 the use of caramel for dyeing cellulose articles is known. DE-PS 3,011,044 shows the purification of a caramel dye by ultrafiltration or dialysis.

An object of the invention is to provide a dye using non-synthetic materials such as the colorants, but natural materials. Another object of the invention is to provide a dye using natural materials having chromophores which have an intensity approximately equal to that of synthetic dyes of the ciromorphs. Another object of the invention is to provide a dye using natural materials such as coloring agents which do not make the cigarette paper fragile.

In this way, the present invention provides a dye for dyeing cigarette wrapping paper in deep brown color.

An advantageous embodiment of the dye of the invention consists of 3 to 20 wt .-% caramel, 2 to 8 wt .-% glycerol and 72 to 95 wt .-% water.

A further advantageous embodiment of the dye according to the invention consists of 3 to 20 wt .-% refined caramel, 1.0 to 10 wt .-% 2X carmine solution, 2 to 8 wt .-% glycerol and 62 to 94 wt .-% water.

A further advantageous embodiment of the dye of the invention consists of 3 to 20 wt .-% caramel, 1.0 to 10 wt .-% 2X carmine solution, 2 to 8 wt .-% glycerol, 3 to 9 wt .-% citric acid and 53 to 91% by weight of water.

The process of the present invention is characterized by diafiltering the prefiltered extract and, while removing the flow through the diafiltration step, adding an amount of deionized water to the diafiltration step equal to the amount of removed flow to obtain a retained one.

A better understanding of the invention will be had from the following discussion taken in conjunction with the accompanying drawings, in which: 1 is a flow chart of a method used to refine caramel extract, and FIG. 2 is a flow chart of a modified method used to refine caramel extract.

Cigarettes have a tobacco column, which is circumferentially surrounded by a wrapping paper. The invention provides a dye for browning the cigarette wrapper paper consisting of caramel as a colorant, a plasticizer for preventing the paper from becoming fragile after drying the dye, and water. The invention further provides a filter cigarette product with the caramel colored shell.

Caramel is defined according to the 21 Code of Federal Regulations, section 73.85 (April 1, 1988) as follows:

(a) Identity: (1) The color additive caramel is the dark brown liquid or the dark brown

Solid which results from carefully controlled heat treatment of the following food grade carbohydrates: dextrose, invert sugar, lactose, malt syrup (sic), molasses, starch hydrolysates and their fractions, and sucrose.

(2) The acids, alkalis and food grade salts listed in this subparagraph may be used in amounts consistent with good manufacturing practice in support of caramelization.

(I) Acids: Acetic, Citric, Phosphoric, Sulfuric, Sulfurous, (II) Alkalis:

Ammonium hydroxide, calcium hydroxide USP, potassium hydroxide, sodium hydroxide, (III) salts: ammonium,

Sodium or potassium carbonate, bicarbonate, phosphate (including dibasic phosphates and monobasic phosphates), sulphate and sulphite.

(3) Polyglycerol esters of fatty acids, which are mentioned in §172.854 of this chapter, may be used as anti-foaming agents in quantities no greater than those necessary to obtain the intended effect.

(4) Caramel color additive mixtures for food use may contain only thinner (sic) suitable and approved in this subsection for color additive mixtures for coloring foodstuffs.

AT 400 385 B (b) Regulations. Caramel must meet the following requirements: Lead (Pb), not more than 10 parts per

Million; Arsenic (ace), not more than 3 parts per million; Mercury (Hg), not more than 0.1 part per

Million.

Preferably, the caramel used as a brown dye in the dye is purified to remove most caramel components that pass through a dialysis membrane having a molecular weight limit of 2,000 to 30,000. This can easily be done by the diafiltration process or alternatively by triturating the caramel with ethyl alcohol and water. In addition, a ten percent solution of the purified caramel powder used in the dye of the invention has an absorbency of 1.20 to 1.50 at 610 nm in a 1 cm cell.

Three samples of caramel color extract were processed to produce purified caramel. The following examples illustrate the methods used in each of the three samples.

Example I

110 Caramel concentrate (55.5% solids) was diluted with deionized water in a ratio of 6: 1 (v: v, water: caramel). The diluted solution was then diafiltered through a five flush membrane into 700 ml of water. The throughput and the retained were collected and the solids content and color intensity determined. The results are summarized in the table below.

Two types of hollow fiber membranes with molecular weight limits of 2,000 and 30,000 were used. The results showed that there were no notable differences in retention of color and solids removal (three quarters of the original solids) between the two membranes. Therefore, it is recommended to choose the membrane with the molecular weight limit of 30,000, since the flow through the membrane increases the molecular weight limit.

Table 1

<td colspan="2" rowspan="2">Fraction # of throughput (volume ml)</td><td colspan="2">% of the total solids</td>

<td>Solids Gew (gf</td><td>away</td>

<td>I</td><td>500</td><td>17.1</td><td>47.1</td>

<td>II</td><td>500</td><td>9.7</td><td>26.7</td>

<td>III</td><td>500</td><td>4.9</td><td>13.5</td>

<td>IV</td><td>500</td><td>2.6</td><td>7.1</td>

<td>V</td><td>500</td><td>1.2</td><td>3.3</td>

<td>VI</td><td>400</td><td>0.39</td><td>1.1</td>

<td>VII</td><td>456</td><td>0.44</td><td>1.2</td>

each 100 g of concentrate

The results (Table I) show that after four 500 ml rinses, approximately 95% of the low molecular weight solids were removed.

200 g and 300 g batches with a 4: 1 or 3.3: 1 dilution factor were dried and cleaning efficiencies were as good as the 100 g batch.

Example II

Fig. 1 shows a flow chart for explaining the method described below.

94.6 liters of caramel color extract were prefiltered, diluted and ultrafiltered using a hollow fiber membrane with a molecular weight limit of 10,000.

The caramel color extract was filtered through a 20μ prefilter to remove particulate matter that could have clogged the membrane during ultrafiltration. The resulting caramel color mixture was diluted with 662 liters of deionized water and ultrafiltered at 40 ° C and a pressure of 1.72 to 2.07 bar. A four-step diafiltration procedure was used, with 757 l throughput at each stage and 757 l deionized water added for constant volume filtration. The diafiitrogenated fourth stage mixture was then concentrated by ultrafiltration to give 173.3 kg of retained solution. Finally, 68.7 kg of concentrate was spray dried in a Niro spray dryer at an inlet temperature of 204 ° C and an outlet temperature of 93 ° C and

AT 400 385 B

6.2 kg of purified caramel powder.

From the caramel color extract, the throughput of 757 L, the throughput of 587 L from the ultrafiltration and concentration step and the purified concentrate were analyzed for dyeing power, soluble solids content and specific gravity. The results are summarized in Table 2 below.

Table 2

<td>sample</td><td>Total Vol. (G)</td><td>spez.Gew.</td><td>% Fixed</td><td>Total solids (kg)</td><td>relative color distribution</td>

<td>Rohkaramel</td><td>25.0</td><td>1,260</td><td>55,00</td><td>65.48</td><td>6900</td>

<td>ger. Konz, (retired)</td><td>44.6</td><td>1,030</td><td>8.98</td><td>15.55</td><td>6422</td>

<td>1. Mixed throughput</td><td>200.0</td><td>1.013</td><td>3.99</td><td>30.49</td><td>418</td>

<td>2.Gemisch throughput</td><td>200.0</td><td>1,000</td><td>1.33</td><td>10.03</td><td>134</td>

<td>3.Gemisch throughput</td><td>200.0</td><td>1,000</td><td>0.43</td><td>3.24</td><td>39</td>

<td>4.Gemisch throughput</td><td>200.0</td><td>1,000</td><td>0.13</td><td>0.98</td><td>20</td>

<td>Throughput of concentrate</td><td>155.0</td><td>1,000</td><td>0.22</td><td>1.29</td><td>213</td>

With reference to the above table, it was found that it would be feasible to reduce the number of ultrafiltration stages from four to three because about 98% of the removable solids were collected in the first three fractions of the throughput.

Example III

Fig. 2 is a flowchart for explaining the method described below.

189.3 liters of caramel color extract were prefiltered, diluted and ultrafiltered using Romicon PM10 hollow fiber membrane cartridges (molecular weight cut-off of 10,000).

The caramel extract was filtered through a 20μ prefilter to remove particulate matter that could have clogged the membranes during the subsequent ultrafiltration. The resulting caramel color mixture was diluted with 757 l of deionized water and ultrafiltered at 40 ° C and a pressure of 1.72 to 2.07 bar. A three-stage diafiltration process was used, with 757 l throughput at each stage and 757 l deionized water added for constant volume filtration. There were three consecutive stages. The final diafiltered mixture was concentrated to 424 L and spray dried as in Example II to give 33.1 Kg of purified caramel powder.

Caramel dyes are characterized by their coloring power and their color index. These are obtained by measuring the color absorbance at 610 nm and 510 nm through a 1 cm cell. The absorptions obtained in Examples I, II and III of all purified caramel were determined. The results (Table 3) show that the method of each example produced a homogeneous purified caramel with good color quality.

AT 400 385 B

Table 3

<td colspan="3">Color index of various samples of purified caramel</td>

<td rowspan="2">Karamelprobe</td><td colspan="2">Absorption of 0.1% W / V shade index</td>

<td>610 nm</td><td>510nm</td>

<td>From example</td><td>III</td><td></td>

<td colspan="3">(Fig. 2)</td>

<td>Mixture # 1</td><td>1.480</td><td>3,640 3.91</td>

<td>Mixture # 2</td><td>1,476</td><td>3,634 3.91</td>

<td>Mixture # 3</td><td>1,466</td><td>3,610 3.91</td>

<td>From example</td><td>II 1,470</td><td>3,548 3.83</td>

<td colspan="3">(Fig. 1)</td>

<td>From example (30,000 mol.)</td><td>I 1,372 Weight limit)</td><td>3,430 3.98</td>

<td>From example</td><td>I 1,442</td><td>----- ----</td>

<td colspan="2">(2,000 mol.wt. limit)</td><td></td>

<td colspan="3">* Tint index (l / | u) = log (Α₅₁₀/ Αθ₁₀) / (0.61 ju-0.51 yy)</td>

As a preferred plasticizer for the dye, glycerol is used. However, other plasticizers, for example propylene glycol, polyethylene glycol, triethylene glycol or the like may also be used.

The dye may contain a red colorant, preferably carmine or a water-based carmine solution, to alter the shade and hue of the caramel's brown color. Carmine is derived from the scale insects Coccus cacti L "Homoptera, commonly known as cochineal. A suitable water-based solution is sold by Crompton and Knowles Corp., 1595 McArthur Blvd., Mahwah, New Jersey under the trade name CARMISOL. For example, For example, a 2X carmine solution, which is a carmine solution containing 7% active carmine, was used in the dye.

Example IV

Four carmine samples were obtained from Cormpton &amp; Knowles Corporation (C &amp; K) for evaluation. The tinting strength of these samples was determined by measuring absorbance at 528 nm using a 0.01% w / v solution as compared to a sample of freeze-dried beet extract. The results are the following:

AT 400 385 Β

Table 4

<td>Red dye sample</td><td>Absorbance at 528 nm (0.01% w / v)</td>

<td>1. L-2665 carmine powder</td><td>1.0899</td>

<td>2. 50-272020-00 carmine solution</td><td>.4570</td>

<td>3. 50-272015-00 carmine solution</td><td>.7465</td>

<td>4. 50-272020-00 carmine solution</td><td>.4700</td>

<td>Beet extract (freeze-dried)</td><td>0.0325</td>

Based on the absorption, carmine powder (L-2665) was the best of the tested samples.

During development of the brown dye formulation using the purified caramel and carmine powder, small carmine particles suspended in the dye solution were found to stain the paper. It has been suggested that the pH of the ink solution may be one of the critical factors in achieving a homogeneous solution. Test results showed that the stain problem can be alleviated by adjusting the pH of the ink solution between 5.7 and 8.6. In addition to 7% active red dye, the preferred carmine solution (called carmine 2X) contains glycerol and KOH.

A typical cigarette wrapper also has a filler that is basic, such as calcium carbonate. Therefore, the dye may also have a pH adjusting agent to adjust the pH of the dye between 5.0 and 10.5, and preferably at 8.6.

One of these pH adjusters, which works well in the dye of the present invention, is potassium hydroxide. However, basic salts and hydroxides can also be used.

Depending on the desired burning rate of the cigarette, a burn rate enhancer or a burn additive may be added to the dye. A suitable fuel additive is potassium citrate. However, other known in this field burning additives may be used, for example, sodium or potassium salts of carboxylic acids such as citric, acetic, tartaric, apple, propionic, capric acid, etc., ammonium phosphate, carbonates or the like.

The foregoing detailed description is provided primarily for the purpose of clear understanding, and it is understood that no undue limitations shall hereto be apparent to those skilled in the art after reading this description, modifications without departing from the spirit of the invention or from the scope of the claims possible are.