GB2253855A

GB2253855A - Carpet backing compositions

Info

Publication number: GB2253855A
Application number: GB9120285A
Authority: GB
Inventors: Brian Bennett; Lesley Anne Meredith
Original assignee: Sandoz AG
Current assignee: Sandoz AG
Priority date: 1990-09-28
Filing date: 1991-09-24
Publication date: 1992-09-23
Also published as: IT1249709B; ITRM910720A1; GB9120285D0; ITRM910720A0; GB9021117D0; FR2667323A1; DE4130948A1; BE1005203A3

Description

2253355 CARPET BACKING COMPOSITIONS The invention relates to quaternised

2-alkyl imidazolines for use primarily as antistatics for bitumen in floor coverings, especially carpets and PVC plastics coverings.

The act of walking on many carpets or other floor coverings generates static charges which accumulate and which discharge if earthed. These can give quite severe shocks to the body and can even be detrimental to electrical equipment. The wear surface of carpets and other floor coverings can often be made conductive by the incorporation therein of antistatic fibres which are capable of dissipating the charge.

A problem which remains is the conductivity of any backing material used in a floor covering. This is typically a PVC plastisol, a bitumen, a propylene or a petroleum resin (such as an aromatic hydrocarbon resin) applied as a liquid or as a hot melt to the reverse of the wear surface, for example to the reverse of a carpet primary backing sheet which comprises the wear surface. Methods of producing carpets using these materials are well known and are described, for example, in US Patents 4, 702,950, 4,582,554 and 4,737,221 the disclosures of which are incorporated herein by reference.

Such materials provide-floor coverings with good dimensional stability and good lay-flat characteristics. They also permit floor coverings to be made in an in-line production method. Many of them, however, especially those based on or containing bitumen, are inherently insulators and they negate any conductivity gains made by, for example, incorporating anti- static fibres into the wear surface.

i'.

It has now been discovered that this disadvantage may be reduced and sometimes even overcome completely by the incorporation of certain chemical compounds into the backing of floor coverings. The invention therefore provides an anti-static backing composition for use in the manufacture of a floor covering, comprising a backing material selected Case 370-5457/F/C from bitumens and hot melt petroleum resins and mixtures thereof, into which is incorporated a compound of formula I N-CH2 v R,-C/ 1 R4e \0 (I) R3 (CH2)nR2 in which R, is C721alkyl or C7-21alkenyl; R2 is OH, -0-COR, -IM2 or -NHCOR where R has the significance of R, independently of R,; R3 is Cl-4alkyl, unsubstituted or monosubstituted by OH, -CH2-C6H5 or - CH2-C-H2; 0 R4 is an anion, preferably, Cl, Br, methylsulphate (MeS04) or ethylsulphate (EtS04); and n is 1 or 2.

Preferably n is 2 and R4 is selected from Cl, Br and methylsulphate (MeS04).

A compound of Formula I is incorporated into the backing material typically at a rate of from 1 to 10% by weight of the backing material. The preferred compounds of Formula I are those wherein:

R2 is hydroxy; n is 2; R, is selected from C11-21alkyl and C15-21alkenyl, preferably C11-17alkyl and C15-21alkenyl; and R3 is selected from methyl and 2-hydroxypropyl.

The backing material is selected from those bitumens and hot melt petroleum resins suitable for use on floor coverings. When a petroleum resin is used, it is preferably an aromatic hydrocarbon resin, but it is Case 370-5457/F/C most preferably a bitumen. The preferred bitumens are those having a softening point (as measured by the ball and ring method of ASTM D36) of 95-1151C and a penetration (as measured by the method of ASTM D5) of 15mm.

The backing material may also contain other materials. One such material is a filler, the most common being limestone, added at a rate of up to 50% by weight of the backing material.

One or more compounds of Formula I may be incorporated into the backing material to give a composition of this invention and the compositions then applied to floor coverings, by conventional means. The floor coverings best suited to the composition of this invention are carpet, particularly non-woven carpet such as carpet tiles, and PVC flooring. The floor coverings which comprise a composition according to the invention have not only the usual desirable properties such as dimensional stability, good lay-flat characteristics and ease of production, but they also exhibit considerably reduced (and often completely non-existent) tendencies to generate static charges. The invention therefore provides a floor covering which comprises at least one layer of a composition according to the invention. The invention also provides a process for the preparation of a floor covering which comprises coating a primary backing sheet with at least one layer of a composition according to the invention.

The invention will now be illustrated by the following Examples.

In the Examples, the bitumen used is one having the following characteristics:

Ball and ring 115 +/- 50C Penetration 15 to 25 mm 11 The method used in the examples for the determination of resistivity is described in the following paragraphs.

The apparatus used is a MEGGER 11Megohmeterll MM29 portable resistivity meter. This is connected to two electrodes. The electrode which is Case 370-5457/F/C placed adjacent to the backing material is a solid brass plate 20 cm square in area and 1cm thick. The electrode which rests on the wear surface (when there is one) is a solid steel cylinder of weight 2.2 kg and a surface area of 31.7 CM2. The area of the sample to be tested is at least that of the brass electrode.

Prior to testing, the samples are conditioned overnight at 201 2'C and 50% relative humidity.

Example 1 g. bitumen and 30 g. limestone are blended, heated to 175'C and stirred until the mixture is homogeneous. 3% of the weight (of the mix) of 1- methyl- 1-hydroxyethyl-2 alkyl-imidazoline methylsulphate (the alkyl group being derived from commercially available coco fatty acid) is added and the mixture is stirred for 10 minutes. The resultant mix is poured on to release paper, pressed to a thickness of 5 mm and allowed to cool. On conditioning, the resistivity is measured and recorded in Table 1.

Example 2

Example 1 is repeated, but using instead of the imidazoline of Example 1, 37. by weight of lmethyl-1- hydroxyethyl-2-alkyl imidazoline methylsulphate (where the alkyl group is derived from coco/palm fatty acid).

Example 3

Example 1 is repeated, but using instead of the imidazoline of Example 1, 3% by weight of 1-methyl-l-hydroxyethyl-2-alkyl-imidazolinemethylsulphate (where the alkyl group is derived from palm oil fatty acid).

Example 4

Example 1 is repeated, but using instead of the imidazoline of Example 1, 3% by weight of 1-methyl-l-hydroxyethyl-2-alkyl-imidazolinemethylsulphate (where the alkyl group is derived from oleic acid).

Case 3705457/F/C Example 5

Example 1 is repeated, but using instead of the imidazoline of Example 1, 3% by weight of 1- methyl-l-hydroxyethyl-2-alkylimidazolinemethylsulphate (where the alkyl group is derived from stearic acid).

L Example 6

Example 1 is repeated, but using instead of the imidazoline of Example 1, 3% by weight of 1-methyll-aminoethyl-2-alkyl-imidazolinemethylsulphate (where the alkyl group is derived from stearic acid).

Example 7

Example 1 is repeated, but using instead of the imidazoline of Example 1, 3% by weight of 1-methyl-l-stearyloxyethyl-2-alkylimidazolinemethylsulphate (where the alkyl group is derived from stearic acid) Example 8

Example 1 is repeated, but using instead of the imidazoline of Example 1, 3% by weight of 1-methyl-l-stearylamido-ethyl-2-alkylimidazolinemethylsulphate (where the alkyl group is derived from stearic acid).

Example 9

Example 1 is repeated, but using instead of the imidazoline of Example 1, 3% by weight of 1-(2rhydroxypropyl)-1-hydroxyethyl2-alkylimidazolinechloride (where the alkyl group is derived from coconut fatty acid).

Table 1

Example 10

Example

No antistat 1 2 3 4 5 6 7 8 9 Resistivity in Ohm X 1012 3 X 108 4 X 108 1.5 X 108 9 X 109 1.6 X 109 2.5 X 1010 5 X 1011 2.5 X 1010 7 X 108 Case 3705457/F/C g. of bitumen are melted at 1751C and 2% by weight of 1-methyl1- hydroxyethyl-2-alkyl-imidazoline-methylsulphate, (where the alkyl group is derived from cocolpalm fatty acid) is added and stirred in for 10 minutes. The resultant mix is Poured on to release papert pressed to a thickness of 3 mm and allowed to cool. On conditioning, the resistivity is measured and recorded in Table 2.

Example 11

Example 10 is repeated using instead of the imidazoline given in Example 10, 4% in weight of 1-methyl-l-hydroxyethyl-2-alkyl-imidazolinemethylsulphate (where the alkyl group is derived from coco/palm fatty acid).

Example 12

Example 10 is repeated using instead of the imidazoline given in Example 10, 6% by weight of 1-methyll-hydroxymethyl-2-alkyl-imidazolinemethylsulphate (where the alkyl group is derived from coco/palm fatty acid).

-7 Example 13

Case 370-5457/F/C Example 10 is repeated except that the bitumen is bonded to nylon carpet containing conductive carbon fiber, rather than to release paper.

Example 14

Example 11 is repeated except that the bitumen is bonded to nylon carpet containing conductive carbon fiber.

Example 15

Example 12 is repeated except that the bitumen is bonded to nylon carpet containing conductive carbon fiber.

Table 2

Example

Resistivity in Ohm Bitumen Alone Carpet Bitumen/Carpet 10 11 12 13 14 15 7 X 1012 2 X 106 6 X 1012 4.4 X 109 4 X 108 4.8 X 107 10 X 109 9 X 108 4 X 106 ---------------- --- -------- --- -8

Claims

Case 370-5457/F/C 1. An anti-static backing composition for use in the manufacture of a floor covering, comprising a backing material selected from bitumens and hot melt petroleum resins and mixtures thereof, into which is incorporated a compound of formula I R.I-C 2 R3 (CH2),,R2 N-CH R4G in which R, is C7-21alkyl or C7-21alkenyl; (I) R2 is OH, -0-COR, -NH2 or -NHCOR where R has the significance of R, independently of R,; R3 is Cl-4alkyl, unsubstituted or monosubstituted by OH, -CI12-C6IiSY or CH2C-H2-; 0 R4 is an anion, preferably, Cl, Br, methylsulphate (MeS04) or ethylsulphate (EtS04); and n is 1 or 2.
2. A composition according to claim 1, wherein R4 is preferably Cl, Br or methylsulphate (MeS04) and n is 2.
3. A composition according to claim 1 or claim 2, wherein R2 is hydroxy; n is 2; R, is selected from Cl,_21alkyl and C15-21alkenyl, preferably C1117alkyl and C15-21alkenyl; and R3 is selected from methyl and 2-hydroxypropyl.

f Case 3705457/P/C
4. A composition according to any one of claims 1 to 3, wherein the composition contains from 1 to 10% by weight of the backing material of the compound of Formula I.
5. A floor covering which comprises at least one layer of a composition according to any one of claims 1 to 4.
6. A process of preparation of a floor covering which comprises coating a primary backing sheet with at least one layer of a composition according to any one of claims 1 to 4.
7. A composition substantially as hereinabove described with reference to any one of the examples.