GB1579247A

GB1579247A - Glue composition

Info

Publication number: GB1579247A
Application number: GB19851/77A
Authority: GB
Original assignee: Extraco AB
Current assignee: Extraco AB
Priority date: 1976-05-21
Filing date: 1977-05-11
Publication date: 1980-11-19
Also published as: CH626913A5; SE411125B; DE2722837A1; NL7705335A; FR2352043B1; SE7605822L; IT1078137B; BE854557A; FR2352043A1

Abstract

The preparation for the production of emerys and abrasives contains bone glue in combination with at least one polyalkylene oxide having a molecular weight of greater than 50,000. Preferred polyalkylene oxides are polyethylene oxides. The proportion of polyalkylene oxide is 0.1 - 10 % by weight, based on the dry weight of the glue. Compared with known additives for improving the flexibility, polyalkylene oxides have no tendency towards migration out of the glue, so that improved permanence of the flexibility of glued joins and glue films can be achieved, and these have no tendency, or a significantly reduced tendency, toward embrittlement.

Description

(54) GLUE COMPOSITION (71) We, EXTRACO AB, a Swedish Body Corporate, ofS-26400Klippan, Sweden, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to flexible glue compositions. More particularly, the invention relates to compositions of particular animal glues and certain polyalkylene oxides.

Animal glues are collagen-based products obtained, for example, from bones and hides. These glues are primarily used for bookbinding, as binders for matches, adhesives for abrasive paper, labels etc., Animal glues have an advantage over synthetic adhesives in that they rapidly become tacky, which, among other things, makes it possible to speed up the run-through times of sizing machines. A disadvantage of animal glues, particularly bone glue, is that they are not sufficiently flexible and thus give glue lines and films which tend to become brittle after some time. In order to make animal glues and thereby glue films more flexible, low molecule hygroscopic substances such as glycerol and sorbitol have mainly been used. Polyglycols having molecular weights up to 4000 have also been used as softeners.At higher molecular weights the hygroscopicity of these substances decreases and thus also their effect as softeners. One disadvantage of these materials is their tendency to migrate from the glue whereby no permanent effect is obtained.

According to the present invention it has been found that flexible compositions of animal glues, giving glue lines and films which do not become brittle on aging, are obtained by the addition of at least one polyalkylene oxide wherein the alkylene groups have from 1 to 4 carbon atoms and having a molecular weight above 50,000 to the glue in an amount sufficient to provide from 0.01 to 10 per cent by weight, based on dry glue, of said polyalkylene oxide. These polyalkylene oxides do not have a tendency to migrate from the glue.

The term "molecular weight" as used herein refers to a weight average molecular weight.

The polyalkylene oxides (polyethers) used according to the present invention are water soluble, non-hygroscopic and have a molecular weight above 50,000.

Preferably, the molecular weight is from 90,000 to 600,000. The alkylene chain comprises alkyl groups having from 1 to 4 carbon atoms, the preferred groups being ethylene groups or a mixture of ethylene and propylene groups. The best results are obtained with polyethers having molecular weights of about 100,000. The upper limit for the molecular weight is set by the limited water solubility of the polyalkylene oxides, the polyethers having molecular weights up to about 6 million can be used. The polyalkylene oxides are used in amounts from 0.01 per cent by weight based on dry glue. The amounts used naturally depend on the intended field of utilization of the resulting glue composition. The upper limit varies with the molecular weight, higher amounts tending to give the resulting glue compositions too long open times.The polyalkylene oxides are preferably used in amounts of from 0.1 to 10 per cent by weight based on dry glue.

Animal glues as used herein refers to bone and hide glues, or combinations of bone and hide glues, i.e. the water-soluble, collagen-based hydrolysis products obtained from water extraction of bones and hides.

As bone glue itself is less flexible than hide glue, the problem with brittle glue lines and glue films thus being more accentuated, compositions of bone glue and polyalkylene oxides are of particular interest. Such compositions according to the invention have been found to be very flexible and to give considerably reduced brittleness. It has also been found that these compositions give considerably more permanent flexibility to glue lines and glue films than conventional bone glue compositions containing, for example, glycerol or sorbitol.

The bone glue compositions of the invention are particularly suitable for the production of abrasive products such as abrasive paper and abrasive cloth. It is known that bone glue is much inferior to hide glue in the abrasive industry.

Abrasive paper produced with bone glue compositions according to the invention has, however, been found entirely comparable with abrasive paper produced with hide glue in grinding tests using wood and metal.

Compositions according to the invention are conveniently prepared in connection with the production of animal glues whereby the polyalkylene oxide(s) is/are mixed into an aqueous solution of the glue, which is then dried. The polyalkylene oxides can also be mixed into a solution of animal glue before the application thereof. The gel strength, which is essential to the glue, is not influenced to any great extent by the addition.

The invention provides a method of making an animal glue composition which method comprises mixing a polyalkylene. oxide wherein the alkylene groups have from 1 to 4 carbon atoms and having a molecular weight above 50,000 with an aqueous solution of bone and/or hide glue in proportions so as to provide from 0.01 to 10 percent by weight based on dry glue of said polyalkylene oxide in a dry composition and drying the resulting mixture.

The invention further provides a method of gluing one substrate to another, which method comprises applying to one or both substrates a composition of the invention or the ingredients thereof separately, contacting the two substrates and permitting the glue to set.

For gluing, the present compositions are generally used as aqueous solutions having dry contents between 25 and 50 per cent and at temperatures above about 400C.

It is also within the scope of the present invention that the present compositions contain at least one conventional additive such as de-foaming agents, preservatives, inert fillers, dyestuffs etc. The glue compositions can, of course, also contain at least one known softener and be used in combination with at least one synthetic adhesive.

Clearly, the present invention embraces the use of a composition in accordance with the invention in the production of an abrasive product. Thus, the invention includes, for example, the use of a composition of the invention and comprising bone glue together with from 0.1 to 10 per cent by weight based on dry glue of polyalkylene oxide having a molecular weight above 50,000 in the production of an abrasive product.

The invention is further illustrated by the following Examples which, however, are not intended to limit the same. In the Examples the amounts given in per cent are per cent by weight amounts based on dry glue.

Example 1 Glue solutions of about 12 per cent were prepared from bone glue, 200 g Bloom, and water. To these were added, with agitation, different amounts of a polyethylene oxide having molecular weight of about 100,000 and glycerol for comparative tests. The effect of the additives was evaluated by tensile and folding tests on glue films of the compositions. Corresponding tests were also made with films from hide glue, 300 g Bloom.

Conditioned glue films (stored for 15 hours at 200C and 60% RH) of dimensions 0.1x10x150 mm were tested both with Aletron TCS 5 kN whereby elongation and force at rupture were measured and also by folding tests according to SCAN P 17. The results below are average of 10 tests.

Added polyethylene oxide 0/, by Elongation Force Number of weight /n N Foldings a) Bone glue - 2.8 91 9 b) Bone glue 1 3.0 86 c) Bone glue 2 3.2 87 33 d) Bone glue 3 3.4 82 e) Bone glue 4 3.0 79 36 f) Bone glue 8 2.9 83 g) Hide glue - 4.6 105 29 Example 2 Films from a) unmodified bone glue of 200 g Bloom b) bone glue with addition of 2 per cent by weight of polyethylene oxide with a molecular weight of about 100.000 c) bone glue with addition of 10 per cent by weight of glycerol and d) unmodified hide glue of 300 g Bloom were stored in a vacuum chamber (less than 60 mm Hg) at 46 C for 24 hours.After conditioning during 24 hours at 230C and 35 /n RH, the films were examined by folding tests according to SCAN P 17. The films had dimensions of 0.05x 10x 150 mm. The results shown below are averages of 15 tests.

Number of foldings a 21 b 124 c 88 d 116 As can be seen in the table immediately above the bone glue compositions according to the invention give glue films having better and more permanent flexibility than conventional compositions, and as good or better flexibility properties compared to those of the hide glue generally used in the abrasive industry.

WHAT WE CLAIM IS: 1. An animal glue composition which comprises bone and/or hide glue and from 0.01 and 10 per cent by weight based on dry glue of at least one polyalkylene oxide wherein the alkylene groups have from 1 to 4 carbon atoms, said polyalkylene oxide having a molecular weight above 50,000.

2. A composition according to claim 1 which contains from 0.1 to 10 percent by weight based on dry glue of said at least one polyalkylene oxide.

3. A composition according to claim 1 or claim 2 wherein the polyalkylene oxide has a molecular weight of from 90,000 to 600,000.

4. A composition according to claim 3, wherein the polyalkylene oxide has a molecular weight of about 100,000.

5. A composition according to any one of claims 1 to 4, wherein the alkylene groups are ethylene groups or a mixture of ethylene and propylene groups.

6. A composition according to any one of claims 1 to 4, wherein the polyalkylene oxide is a polyethylene oxide.

7. A composition according to any one of claims 1 to 6 also containing at least one additive selected from de-foaming agents, preservatives, inert fillers, dyestuffs, softeners and synthetic adhesives.

8. An animal glue composition substantially as hereinbefore described in any one of Examples lb to If, or 2b.

9. A method of making a composition according to any one of claims 1 to 8, which method comprises mixing a polyalkylene oxide wherein the alkylene groups have from 1 to 4 carbon atoms and having a molecular weight above 50,000 with an aqueous solution of bone and/or hide glue in proportions so as to provide from 0.01 to 10 percent by weight based on dry glue of said polyalkylene oxide in a dry composition and drying the resulting mixture.

10. A glue composition which has been made by a method according to claim 9.

11. A method of gluing one substrate to another, which methodiomprises applying to one or both substrates a composition according to any one of claims 1

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. Added polyethylene oxide 0/, by Elongation Force Number of weight /n N Foldings a) Bone glue - 2.8 91 9 b) Bone glue 1 3.0 86 c) Bone glue 2 3.2 87 33 d) Bone glue 3 3.4 82 e) Bone glue 4 3.0 79 36 f) Bone glue 8 2.9 83 g) Hide glue - 4.6 105 29 Example 2 Films from a) unmodified bone glue of 200 g Bloom b) bone glue with addition of 2 per cent by weight of polyethylene oxide with a molecular weight of about 100.000 c) bone glue with addition of 10 per cent by weight of glycerol and d) unmodified hide glue of 300 g Bloom were stored in a vacuum chamber (less than 60 mm Hg) at 46 C for 24 hours.After conditioning during 24 hours at 230C and 35 /n RH, the films were examined by folding tests according to SCAN P 17. The films had dimensions of 0.05x 10x 150 mm. The results shown below are averages of 15 tests. Number of foldings a 21 b 124 c 88 d 116 As can be seen in the table immediately above the bone glue compositions according to the invention give glue films having better and more permanent flexibility than conventional compositions, and as good or better flexibility properties compared to those of the hide glue generally used in the abrasive industry. WHAT WE CLAIM IS:

1. An animal glue composition which comprises bone and/or hide glue and from 0.01 and 10 per cent by weight based on dry glue of at least one polyalkylene oxide wherein the alkylene groups have from 1 to 4 carbon atoms, said polyalkylene oxide having a molecular weight above 50,000.

10. A glue composition which has been made by a method according to claim 9.

to 8 or 10, or the ingredients thereof separately, contacting the two substrates and permitting the glue to set.

12. A method according to claim 11, wherein the composition is employed as an aqueous solution having a dry content of from 25 to 50 per cent and at a temperature above 40"C.

13. A product which comprises substrates which have been glued together by a method according to claim 11 or claim 12.

14. A product according to claim 13 which is abrasive.

15. A product according to claim 14 which is abrasive paper or abrasive cloth.

16. The use of a composition according to any one of claims 1 to 8 or 10 in the production of an abrasive product.

17. The use of a composition according to claim 1 and comprising bone glue together with from 0.1 to 10 per cent by weight based on dry glue of polyalkylene oxide having a molecular weight above 50,000 in the production of an abrasive product.