NO812480L - PREPARATION FOR USE IN CROSS RELEASE OF TEXTILES - Google Patents

Description

The invention relates to a urea/aldehyde preparation. In a particular aspect, the invention relates to a preparation of urea/aldehyde resin which has special application for the treatment of textiles and non-woven cellulose products.

The importance of dimensional stability, such as crease resistance and lasting pressing properties in textiles and non-woven cellulose products is well-established and of great importance and economic value to the textile industry. The bulk of textile articles, both garments and household articles, which are available on the market, exhibit these properties to a certain advantageous degree. Although many synthetic fibers inherently possess flexibility and creasing resistance, fabrics containing cellulosic fibers must be chemically treated to obtain these important properties required for the modern textile market.

In addition to creasing resistance and permanent pressing properties, it is highly desirable that non-woven cellulose products show good wet strength characteristics. Even so, most paper articles are particularly deficient in wet strength unless treated.

The main chemical treatments that provide crease resistance and lasting pressing properties in cellulose-containing textiles and non-woven products are those where the cellulose molecules are cross-linked, generally by reacting a di- or poly-functional agent with the cellulose. Many of the agents used in the textile processing industry to produce lasting pressing properties in cellulosic fabrics are N-methylol adducts formed by reacting nitrogen-containing compounds with formaldehyde. In order to improve the reactions between the cellulose and these adducts, many compounds or catalysts can be used.

Currently, urea/formaldehyde and urea/glyoxal resins (ie the ethylene-urea compounds) are used in large volume. However, glyoxal is a high-cost raw material and it would be advantageous to use the more economical urea/formaldehyde resin. Other products commonly used to provide curl resistance include cellulose binders, such as carbamates, triazones, melamines and methylolmelamines.

All these products present a different problem ie.

that they result in residual free aldehyde, for example formaldehyde, on the cloth or on another object, which is

boring because it tends to pollute the environment. Likewise, many other industries that use formaldehyde-based resins are faced with attendant health problems involving formaldehyde.

It is an object of the invention to provide an improved process for treating cellulose fibers and other fibers, and to provide a urea/aldehyde resin mixture which is particularly useful for treating textiles and non-woven cellulose products.

Accordingly, the invention provides a preparation comprising a cross-linking agent and a nitroalkane with 1-3 carbon atoms or a nitroalkanol or a mixture thereof in a molar ratio of from 0.25 to 3.0 per moles of urea..

The nitroalkanol is represented by the following formula:

where R and R"'" are hydrogen, methyl, ethyl or hydroxymethyl and can be the same. or different. Preferably, but not necessarily, the composition is provided as an aqueous dispersion or solution. It is also intended that the mixture can be prepared by the user immediately before application to the textile or fabric.

Instead of the nitroalkanol, a nitroalkane with 1-3 carbon atoms can be used in an amount that is equimolar with the amount of nitroalkanol used. Furthermore, a mixture in any ratio between nitroalkane and nitroalkanol of the above formula can be used.

It is an embodiment of the invention that the remaining free aldehyde in an aldehyde-containing resin, for example urea/formaldehyde or urea/glyoxal, or an aldehyde-based cross-linking agent or a product containing the same, can be significantly reduced by using a nitroalkane or a nitroalkanol together with the resin, for example a urea/aldehyde resin, or a cross-linking agent. The term "aldehyde-based" shall mean that the resin or cross-linking agent has an aldehyde, usually formaldehyde, as one of the reactants in its manufacture.

It is not intended to limit the invention to textile processing. Rather, it is contemplated that nitroalkanols are useful in conjunction with all aldehyde-based resins, monomers, cross-linking agents, and methods and products that an- . reverses them, such as phenol/formaldehyde resins etc.

It is another embodiment of the invention to provide a method for improving the grip on wrinkle-resistant textiles and non-woven fabrics by treating these with a nitroalkanol of the previously stated formula.

The invention will be discussed in detail below. The preparation according to the invention is a mixture of

a resin, monomer or other cross-linking agent, generally but not necessarily adapted to impart crease resistance and durable pressing properties to textiles, such as a curable urea/aldehyde or other aldehyde-containing resin or monomer thereof, many of which are known, and a nitroalkanol or a nitroalkane or a mixture thereof. The term "curable" shall mean that the cross-linking agent, monomer or resin is incompletely polymerized and is capable of further reaction with cross-linking agents and the like. In the following, the term "crosslinking agent" shall include aldehyde-based monomers, resins and binders.

The urea/aldehyde resins according to the invention are

either a urea/formaldehyde resin or a urea/glyoxal resin (ie ethylene urea), preferably urea/formaldehyde. Substituted urea can also be used when forming the resin. Instead of resins, many aldehyde-based monomeric substances are used as cross-linking agents for the molecules in the textile. Commonly used ones include, but are not limited to, carbonates, for example 2-methylethyl carbarnate; modified

.melamines, for example methylated methylolmelamines; the ethyleneurea compounds; and triazones, for example as disclosed in US Patent 2,917,411. More particularly are the following compounds, all of which are prepared using an aldehyde, namely formaldehyde, which. raw material, usually: dimethylolurea; dimethoxymethylurea; methoxymethylmel.amine (trimethoxymethyl to hexamethoxy); dimethylolalkanediol diurethane; dimethylolethylene urea; dimethyloldihydroxyethylene urea; dimethylolpropylene urea; dimethylol-4-methoxy-5,5-dimethylpropyleneurea; dimethylol-5-hydroxy-propyleneurea; dimethylohexa hydrotriazinones; dimethoxy-rne ty lur eo n ; tetramethylolacetylenediurea; dimethylocarbarnates

with the following formula:

where R is alkyl, hydroxyalkyl or alkoxyalkyl; methylol acrylamide; dimethylolalcanediols.

The method according to the invention for strong reduction or removal of free formaldehyde, as well as other embodiments, can be used in processes that use the above-mentioned cross-linking agents.

The amount of nitroalkane or nitroalkanol used is not critical, but if urea/formaldehyde is the relevant resin, then the amount used is in the range from 0.25 to 3.0 mol per moles of urea used in the production of the resin. For example, urea/formaldehyde resin is generally produced, as is known in the field, in a molar ratio of approx. 1 to 1-5. Consequently, the amount of nitroalkane, for example nitromethane, which is used would be in the range of from approx. 5 to 90 g per 100 g of resin, if the urea/forrnaldehyde is in a respective Is ratio; or if the urea/formaldehyde is in a ratio of 1:1, the amount of nitromethane would be in the range of from approx. 15-200 g of resin. If the nitroalkanol is 2-nitro-2-methyl-1-propanol (NMP), then an amount of from approx. 115 to 350 g per 100 g of resin if the urea/formaldehyde is in a 1:1 ratio. If the ratio is 1:5, then the NMP used is in: the range from approx. 50 to 150 g per 100 g of resin. If other nitroalkanes and/or nitroalkanols are used, the amounts are proportional to the nitromethane and/or NMP. If the resin is of the urea/glyoxal type, comparable amounts of nitroalkane and/or nitroalkanol are used.

If other permanent press resins or aldehyde-containing cross-linking agents are used, then the amount of nitroalkanol or a nitroalkane to be used is in the general range of 18-142 parts per 100 parts by weight of the resin. However, the area is not critical.

It is another embodiment of the invention to react the urea/formaldehyde resin with up to 1.5 mol of glyoxal per moles of urea before mixing with the nitroalkanol or nitroalkane or mixture thereof. It is also within the framework of the invention that melamine can be used as a cross-linking agent instead

glyoxan.

The nitroalkanols useful in the practice of the present invention are commercially available and include, but are not limited to, tris(hydroxymethyl)nitromethane; 2-nitro-2-methyl-1,3-propanediol; 2-nitro-2-ethyl-1,3-propanediol; 2-nitro-1-butanol and, preferably, 2-nitro-2-methyl-1-propanol. Mixtures of these nitroicanols are also used. It can be understood that the invention is not limited to these nitroalkanols. Other nitroalkanols are known in the art and are considered to be the close equivalents of the above.

The nitroalkanes useful in the practice of the present invention are commercially available and include nitromethane, nitroethane, 1-nitropropane, 2-nitropropane and mixtures thereof. The total nitroalkane is preferably used in a proportion of approx. 0.5-1.0 mol, and 0.75 mol is particularly preferred, per moles of urea. It should be understood that the invention is not limited to these nitroalkanes. Others are known in the field and are considered to be close equivalents of the foregoing.

If nitromethane is used as the nitroalkane, it is also preferred to add 3 mol of formaldehyde per moles of nitromethane. If chifroethane or 1-nitropropane is used, it is preferred

to add 2 moles of formaldehyde per moles of nitroalkane. If 2-nitropropane is used, it is preferred to add 1 mol of formaldehyde per moles of nitroalkane.

The urea/aldehyde resins and other cross-linking agents such as

are useful in the practice of the present invention are known in the field and are commercially available for the production of wrinkle-resistant textiles and non-woven cellulose products. The resins and other cross-linking agents are incompletely polymerized so that when they are impregnated, for example as an aqueous dispersion, on the textile, further polymerisation, or curing, takes place by heating.

Urea/formaldehyde resins used for this purpose are generally produced by reacting formaldehyde and urea under alkaline conditions, for example at a pI-I value of approx. 7-11, preferably 8.0-10.5 and especially approx. 10.0-10.5. The pH can be provided by any alkaline reagent, many of which are known, namely inorganic carbonates, bicarbonates, oxides or hydroxides, including those of sodium, potassium and lithium. Sodium hydroxide is preferred.

The preferred urea/formaldehyde resins used in the practice of the present invention are produced in a molar ratio of 4-6 moles of formaldehyde per moles of urea. Such resins are generally known to those skilled in the art as uronic resins, in contrast to those which form at an rnol ratio of up to 3:1. Analysis by means of nuclear magnetic resonance on a sample (without nitroalkane or nitroalkanol) of the product according to the invention indicated the following:

The conversion of formaldehyde and urea is preferably, but not necessarily, carried out under alkaline conditions at elevated temperatures of from approx. 40°C to reflux temperature at ambient pressure, preferably at reflux temperature. When the reaction is finished, the reaction mixture is cooled to approx. 55-65°C, and the pH value is adjusted to approx. 5.0-7.0. The pH adjustment can be performed with any water-soluble mineral or organic acid. In general, a dilute acid, for example dilute hydrochloric acid, phosphoric acid, sulfuric acid, p-toluenesulfonic acid, will be used. The heating period is then continued at 55-60°C

for about. 1 more hour to ensure complete turnover. The reaction product is then allowed to cool, and if desired, it can be diluted to approx. 25-45% solids, which speeds up the cooling process.

The urea/glyoxal resins useful in the practice of the present invention are known in the art. They are commercially available from, for example, Sun Chemical Corporation, Chester, South Carolina, under the trade name "Permafresh". Any of the urea/glyoxal resins may be used in the practice of the present invention.

A 25% dispersion or solution of the resin mixture is preferred in the field for treating the textile product or another non-woven, cellulosic product. Preferably, it is used together with a catalyst, for example magnesium chloride or zinc nitrate. It is convenient to prepare the catalyst as a 25% aqueous solution and mix 1 part of the catalyst solution with 4 parts of the 25% resin solution. The product of textile or other non-woven cellulosic material is then saturated with the mixture, pressed to approx. 60% wet absorption and is heated at, for example, approx. 177°C for curing the resin.

It is within the scope of the invention that the products and articles that will benefit from the wrinkle resistance imparted by the resin according to the invention will include, but not be limited to, those made from natural fibers, principally wool and cellulose, both woven and non-woven. Of the woven fibers, cotton fibers are expected to benefit the most. Nonwovens are usually made from cellulose fibers, such as wood fibers, and are widely used. Although much of it goes to disposable items where wrinkle resistance does not need to be of great importance, the market for durable prints is constantly growing, especially when it comes to clothing, bedding, carpets, curtains, etc., where wrinkle resistance is important . The term "substance" as used herein is intended to include such a cellulosic product. In fact, it is within the scope of the invention that any cellulosic product, including, but not limited to, textiles, paper goods, particle board, laminated veneer and the like, to be treated with a cross-linking agent, such as a urea/aldehyde resin, will benefit from treatment with a nitroalkane or a nitroalkanol.

Significant advantages derive from the use of nitro- . alkanes and nitroalkanols when treating textiles and non-woven cellulose products with urea/aldehyde resins.

The treated substances have greatly improved "grip" when the treatment is carried out in the presence of nitroalkanes or nitroalkanols, and the remaining aldehyde is greatly reduced, thereby improving the environment. Furthermore, the present invention makes it possible to use cheap urea/formaldehyde (uron) resins in the anti-crease process and still give results which are comparable to, or better than, the expensive resins such as, for example, the urea/glyoxal resins. Furthermore, the nitroalkanols cause faster curing of the resins at the temperatures usually used, or at lower temperatures, and they give better curing, which gives a better recovery angle. Thus, they tend towards conservation of energy. Other advantages will also be apparent to the person skilled in the art.

The invention will be better understood by reference to the following examples. It is to be understood that the examples are intended for illustration only, and the invention is not intended to be limited by them.

Example 1

324 g (4 mol) formaldehyde, 37% solution, and 60 g (1 mol) urea were placed in a reaction vessel equipped with a cooler and agitator. The pH was adjusted to 10.8 with 50% NaOH. The mixture was heated to 60°C for 5 hours, thereby forming a solution of a conventional urea/formaldehyde prepolymer.

The mixture was divided into two parts, 192 g each. One part was set aside and designated solution A. To the other part, solution B, was added 76.2 g of a 65% aqueous solution of 2-nitro-2-methyl-1-propanol (4 9.53 g dry matter basis,

0.48 mole) and 41', 54 g of water to provide 45% total solids. This solution was further diluted to 25% solids by adding 44.5 parts of water per 55.5 parts of solution B. To 100 parts of this solution was added 25 parts of magnesium chloride, 25% aqueous solution.

The creep recovery was determined by Test Method 66-1968

.from the American Association of Textile Colorists and Chemists. A piece of cotton cloth, without finishing, bee dipped in the resin solution, patted dry and stretched and then placed in

an oven at 180°C for 90 seconds. ■ Ten test pieces, 40 mm long and 15 mm wide, were cut out of the fabric, five pieces with their longitudinal dimension parallel to the warp and five with their longitudinal dimension parallel to the islet. The recovery angle was then measured, as indicated in the test method for the test pieces. The values were averaged, and these were expressed as total recovery angle. Similar test pieces were treated with the same resin solution (A), but without the addition of NMP. The obtained results are reproduced in the table. Reduction in residual free formaldehyde was remarkable. The fabric treated with solution (B) had much better grip than that treated with solution (A).

A sample of non-woven cellulose material is treated with this resin. It has high wet strength and good dimensional stability.

Oak sample 2

910 g (11.2 mol) of formaldehyde, 36% aqueous solution, was dropped into a round bottom flask and the pH was adjusted to 7.5. 120 g (2 mol) of urea were added. Stirrers, cooler and thermometer were connected. The reaction mixture was heated for 2 hours at reflux with stirring. It was then allowed to cool, and the solution, 45.16% solids, was divided into two parts, designated A and B respectively.

Part A was diluted to approx. 2 5% by adding 44.5 parts water. to 55.5 parts of A. Then 25 parts of a 25% solution of magnesium chloride id. were added. This solution was used as a control for the treatment of cloth as described in example 1.

Part B, 465 g, was mixed with 152.4 parts of a 64.8% solution of NMP, giving a total of 617.4 g of a 50% solution. Then 68.55 g of water was added so that. a 25% solution was obtained. To 55.5 parts of this solution was then added

■44.5 parts water so that a 25 l solution was obtained, and finally 25 g of a 25% solution of magnesium chloride was added. This solution was then used for the treatment of cloth. The results are reproduced in the table. That cloth. which was treated with NMP and resin showed good grip - smooth and soft.

The control fabric was smooth but stiff. A sample of non-woven cellulosic material is treated with

this resin. It has high wet strength and good dimensional stability.

Example 3

The experiment from example 2 was repeated in all essential details, with the exception that urea and formaldehyde were reacted in a molar ratio of 1:1.6 respectively. The control fabric had a poor grip - it felt stiff and rough. The fabric treated with NMP had good grip, was smooth and flexible. The data is reproduced in the table.

A sample of non-woven cellulose material is treated with this resin. It has high wet strength and good dimensional stability.

Ek sample A

The experiment from Example 1 is repeated in all essential details, with the exception that 2-nitro-l-butanol is used instead of NMP. Cotton cloth treated in this way shows a high recovery angle. A sample of non-woven cellulose material treated in this way has high wet strength and good dimensional stability.

Example 5

The experiment from Example 1 is repeated in all essential details, with the exception that tris(hydroxymethyl)nitromethane is used instead of NMP in equimolar amounts. Cotton cloth treated in this way shows a high recovery angle. A sample of non-woven cellulosic material treated in this way has high wet strength and good dimensional stability.

Oak sample 6

The experiment from Example 1 is repeated in significant detail, with the exception that 2-nitro-2-methyl-1,3-propanediol is used instead of NMP. Cotton fabric treated in this way shows a high recovery angle. A sample of non-woven cellulosic material treated in this way has high wet strength and good dimensional stability.

Example 7

The experiment from example .1 is repeated in all essential details, with the exception that 2-nitro-2-ethyl-1,3-propanediol is used instead of NMP. Cotton fabric treated in this way shows a high recovery angle. A sample of non-woven cellulosic material treated in this way has high wet strength and good dimensional

Example 8

The experiment from Example 1 is repeated in all essential details, with the exception that nitromethane is used instead of NMP on

equimolar basis and that 3 mol of formaldehyde per moles of nitromethane are added. Cotton cloth treated in this way shows a high recovery angle. A sample of non-woven cellulosic material treated in this way has high wet strength and good dimensional stability.

Oak sample 9

The experiment from example 1 is repeated in all essential details, with the exception that nitroethane is used instead of NMP on an equimolar basis and that 2 mol of formaldehyde per moles of nitroethane are added. Cotton cloth treated in this way shows a high recovery angle. A sample of non-woven cellulosic material treated in this way has high wet strength and good dimensional stability.

Example 10

The experiment from example 1 is repeated in all essential details, with the exception that nitropropane is used instead of NMP on an equimolar basis and that 2 mol of formaldehyde per moles of nitropropane are added. Cotton cloth treated in this way shows a high recovery angle. A sample of non-woven cellulosic material treated in this way has high wet strength and good dimensional stability.

Oak sample 11

The experiment from example 1 is repeated in all essential details, with the exception that after the urea/formaldehyde resin has been prepared, it is further heated at 50°C for 2 hours with 0.5 mol of glyoxal per moles of urea. The pH is adjusted to 9.2, and 2-nitro-2-methyl-1-propanol (0.75 mol) is added. This mixture is used for the treatment of cotton fabric and a sample of non-woven cellulose material.

Example 12

A. To 55.5 ml of a 45% aqueous solution of a urea/glyoxal resin was added 44.5 ml of water. The resin was supplied by Sun Chemical Company and was designated "Permafresh LF". To this solution was added 22 g of a 65% solution of NMP and 25 ml of a 25% magnesium chloride solution, giving a total of 150 ml. The pH value was adjusted to approx. 5 with 1% sodium hydroxide solution. A fabric sample was treated with this solution and tested with consideration of curl recovery, as described in example 1. The results are reproduced in the table.

B. The above experiment was repeated in all essential details, with the exception that 25 ml of water was used instead of NMP. The results are reproduced in the table.

Example 13

The experiment from Example 12A is repeated in all essential details, with the exception that 1-nitropropane is used instead of NMP on an equimolar basis and that 2 moles of formaldehyde are added. A wrinkle-resistant fabric is obtained.

Example 14

The experiment from Example 13 is repeated in all essential details, with the exception that nitromethane is used instead of NMP on an equimolar basis and that 3 moles of formaldehyde are added.

A wrinkle-resistant fabric is obtained.

Example 15

The experiment from Example 13 is repeated in all essential details, with the exception that 1 mol of 2-nitropropane and 1 mol of formaldehyde are used instead of NMP. A crease-resistant finish is achieved. fabric.

Example 16

The experiment of Example 1 is repeated in all essential details, except that Superez AVG, a carbamate resin manufactured by Proctor Chemical Company, is used instead of urea/formaldehyde. The substance that had been treated with NMP,

has very good grip compared to that which had not been treated with NMP.

Oak sample 17

The experiment of Example 1 is repeated in all essential details, with the exception that Resimenl 842, a methylated methylolmelamine manufactured by Monsanto Chemical Company,

is used instead of urea/formaldehyde. The fabric that was treated with NMP has very good grip compared to that which was not treated with NMP.

Example 18

The experiment from Example 1 is repeated in all essential details, with the exception that Reactant-4 75, a triazone resin manufactured by Quaker Chemical Company, is used instead of urea/formaldehyde. The substance that had been treated with NMP

has very good grip compared to that which had not been treated with NMP.

The crosslinking agent was a 43% buffered solution of 4,5-dihydroxy-1,3-dimethylolethyleneurea (Protocol C), marketed by Proctor Chemical Company). The catalyst was a 50% solution of zinc nitrate.

Samples of cotton fabric were treated with the above preparations and were dried for 90 seconds at 132°C. They were then cured by heating at 177°C for 60, 120 and 240 sec., respectively. The rest of free formaldehyde on the cloth was then determined. The results were as follows.

Example 2 0

■The experiment from Example 19 was repeated in all essential details, with the exception that the concentration of cross-linking agent was doubled, and this gave the following recipes:

Residual formaldehyde on the cloth after curing was as follows:

Claims (17)

1. Preparation for decreasing textiles, characterized in that it comprises a cross-linking agent and a nitroalkanol with the following formula: where R and R are hydrogen, methyl, ethyl or hydroxymethyl and may be the same or different, or a mixture thereof. 2. Preparation as stated in claim 1, characterized in that the nitroalkanol is present in an amount of from 0.18 to 1.4 2 parts per part of resin, by weight. 3. Preparation as stated in claim 1, characterized in that the cross-linking agent is an ethylene urea, a carbamate, methylated methylolmelamine or a triazone. 4. Preparation as stated in claim 3, characterized in that the cross-linking agent is ethylene urea. 5. Preparation as stated in claim 3, characterized in that the cross-linking agent is a carbamate. 6. Preparation as stated in claim 3, characterized in that the cross-linking agent is a triazone. 7. Preparation as stated in claim 3, characterized in that the cross-linking agent is methylated methylolmelamine. 8. Preparation as stated in claim 1, characterized in that the nitroalkanol is 2-nitro-.2-methyl-1^propanol. 9. Preparation as stated in claim 1, characterized in that the nitroalkanol is tris(hydroxymethyl)nitromethane. 10. Preparation as stated in claim 1, characterized in that the nitroalkanol is 2-nitro-2-methyl-1,3-propanediol. 11. Preparation as stated in claim 1, characterized in that the nitroalkanol is 2-nitro-2-ethyl-1,3-propanediol. 12. Preparation as stated in claim 1, characterized in that the nitroalkanol is 2-nitro-1-butanol. 13. Method for producing a wrinkle-resistant fabric, characterized in that the fabric is impregnated with the preparation according to claim 1, and that it is then heated to 107-177°C for curing. 14. Preparation, adapted for the treatment of a textile product or a non-woven cellulose product, characterized in that it comprises a cross-linking agent which is adapted to transfer crease resistance and lasting pressing properties, and a nitroalkane with 1-3 carbon atoms, or a mixture thereof. 15. Preparation as stated in claim 14, characterized in that the nitroalkane is present in an amount of 18-142 parts per 100 parts resin, by weight. 16. Preparation as stated in claim 14, characterized in that the resin is ethylene urea, et. carbamate, methylated methylolmelamine, or a triazone. 17. Method for producing a wrinkle-resistant fabric, characterized in that the fabric is impregnated with the preparation according to requirements. 14, after which it is heated to 107-177°C to cure the resin.