WO1995018883A1

WO1995018883A1 - Low sling fiber lubricant containing a shear reduced mixture of high and low molecular weight polymers

Info

Publication number: WO1995018883A1
Application number: PCT/US1993/012370
Authority: WO
Inventors: John T. Childers
Original assignee: Henkel Corporation
Priority date: 1993-12-29
Filing date: 1993-12-29
Publication date: 1995-07-13

Abstract

A low-sling, high tack fiber lubricant having a final viscosity of from 50 SUS to 200 SUS characterized in that the lubricant contains: a mineral oil-vehicle; a high molecular weight oil-soluble polymer having a number average molecular weight in the range of from 3,500,000 to 7,500,000 selected from: (i) polyisobutylene homopolymer; (ii) a polymer of straight chain alpha-monoolefins/having 4 to 20 carbon atoms; and (iii) a copolymer of isabutylene and straight chain alpha-monoolefin; a low molecular weight oil-soluble polyisobutylene homopolymer having a number average molecular weight in the range of from 500,000 to 3,000,000 and an emulsifier or mixture of emulsifiers wherein the ratio by weight of component (b) to component (c) is from 9:1 to 1:9, wherein said lubricant is prepared by a process comprising selecting a mineral oil vehicle having a viscosity from about 5 to 50 SUS lower than the final viscosity of the lubricant; admixing components (b), (c) and (d) into the mineral oil vehicle to provide an admixture having viscosity of from 5 to 30 SUS above the final viscosity of the lubricant, and applying controlled low shear force to the admixture containing the polyisobutylene additive to reduce viscosity of the admixture to the final viscosity of the lubricant.

Description

LOW SLING FIBER LUBRICANT CONTAINING A SHEAR REDUCED MIXTURE OF HIGH AND LOW MOLECULAR WEIGHT POLYMERS

This- invention relates to low sling fiber lubricants for use in the textile industry. Low-sling additives for fiber lubricants, especially coning oil type lubricants, are well-known in the art as protective coatings for fibers in a variety of textile operations. Many of these additives, particularly relatively low molecular weight polymers such as polyisobutylene, are in common use to improve adherence of the lubricant to the fiber and reduce lubricant "sling-off" during yarn winding operations.

While these additives have proved generally useful in lubricants for low-to-mediuir speed fiber winding operations (for example, for yarn speeds up to about 300 meters/minute) , in ultra high speed winding operations conventional low molecular weight polyisobutylene and comparable low-sling polymer additives have not sufficed to reduce lubricant slign-off to acceptable levels. Further, these known additives are not uniformly reliable and tend to perform erratically under varying process parameters, particularly with respect to fiber type, yarn speed, machinery characteristics, processing temperatures, and recirculation conditions. For general commercial acceptability, it is important that fiber lubricants for man-made fibers reduce friction between the yarn and contact surfaces, for example surfaces of processing machinery or interfaces with other fibers; adhere to the yarn to reduce sling-off during processing; and be scourable to permit substantially complete removal before downstream operations such as dyeing and finishing, with which lubricant residue would substantially interfere. It is particularly important that lubricant compositions consistently function well to perform these tasks under a variety of operating conditions, in order to obviate the necessity of reevaluating and reformulating each lubricant composition on an ad hoc basis. Improved yarn processing lubricants are disclosed in U.S. Patent No. 4,400,281. These lubricants are based on polymeric additives which are homopolymers and copolymers of straight chain alpha-monoolefins containing from 4 to 20 carbon atoms. A significant improvement in high-tack fiber lubricants is disclosed in U.S. Patent No. 4,767,556. The high-tack fiber lubricants of that invention have broad applicability and exhibit low-sling characteristics over a broad range of fiber types, lubricant add-on requirements, and yarn processing conditions. Lubricants according to that invention are especially useful in ultra high speed winding operations, particularly those involving yarn speeds in excess of about 700 meters/minute, wherein lubricant sling-off is minimized while adequate fiber lubrication and scourability are maintained. The lubricants disclosed in U.S. 4,767,556 utilize high molecular weight polyisobutylene additives compounded with mineral oil vehicles under very low shear conditions. While the above high-tack fiber lubricants are highly effective, coning oil misting and droplet formation will still occur to some extent at very high winding speeds.

The present invention is directed to high-tack fiber lubricants that exhibit even more reduced coning oil misting and droplet formation, even when very high winding speeds are utilized, including yarn speeds of 900 meters/minute or faster. In addition, the high-tack fiber lubricants of the invention have broad applicability and exhibit low-sling characteristics over a broad range of fiber types, lubricant add-on requirements, and yarn processing conditions.

The lubricant compositions of the invention comprise: a) a high molecular weight oil-soluble polymer having a number average molecular weight in the range of from

3,500,000 to 7,500,000 selected from one or more of the following:

(i) polyisobutylene homopolymer, (ii) a homopolymer of a straight chain alpha- onoolefin having 4 to 20 carbon atoms, or a copolymer of two or more of such onoolefins, and

(iii) a copolymer of isobutylene and a straight chain alpha-monoolefin having 4 to 20 carbon atoms in which the isobutylene is present in from 10 to 99% by weight; b) a low molecular weight oil-soluble polyisobutylene homopolymer having a number average molecular weight in the range of from 500,000 to 3,000,000; c) an emulsifier; and d) a mineral oil vehicle.

The ratio by weight of component a) to component b) is from 9:1 to 1:9. This ratio is preferably from 1:2 to 2:1 when component a) is a polyisobutylene homopolymer and is preferably from 1:2 to 1:5 when component a) is a component a) (ii) or a) (iii) .

The molecular weight of component a) is preferably in the range of from 5,000,000 to 6,000,000.

The molecular weight of component b) is preferably in the range of from 1,000,000 to 2,000,000.

For use in the compositions of the invention, the polymers (components a) and b) ) are generally employed in oil solutions; typically the polymer additives are incorporated into the lubricant as solutions comprising 90 to 95% mineral oil, with the balance polymer additives. Conveniently, the polymer additives are predissolved in a portion of the oil vehicle to form an additive solution by processes known in the art for dissolving solid polymers of this type in oil, as by heating for the required period of time. Alternatively, a commercially available product comprising a solution of polymer in oil is employed. The polymer "additive solutions" referred to herein are additive solutions comprising 5% polymer (components a) plus b) ) and 95% oil by weight; equivalent fiber lubricants according to the invention are prepared by using additive solutions containing more or less polymer by proportion, and adjusting the amount of additive solution employed in the lubricant to give an equivalent concentration of polymer.

The polymer additives are incorporated into component d) -the oil vehicle, conveniently mineral oil characterized by a viscosity of from 40 to 200 SUS at 100°F (37.8°C - all viscosity measurements recited herein are in SUS at 37.8°C), in an amount sufficient to obtain the requisite level of lubricant tackiness for the particular application, with particular reference to fiber type, yarn speeds, yarn travel conditions (e.g., yarn jerking on slack take-up), incidence of yarn contact points (e.g., yarn bumping) , and the range of lubricant add-on employed to achieve fiber protection. Generally, as previously noted, additive content of the lubricant is adjustable within a narrow range according to the invention to achieve optimally reduced oil sling under a variety of fiber processing parameters, thereby obviating the extensive experimentation necessary to achieve good results under some prior art guidelines.

The polymer additives are incorporated into the mineral oil vehicle in conjunction with one or more emulsifiers in sufficient quantities to stabilize and homogenize the formulation and afford scourability of the lubricant from the synthetic material. The emulsifiers are added in amounts typically ranging from 5% to 20% by weight of the total product and more typically from 10 to 18% by weight. In high speed applications of the type described supra, employing component a) plus component b) in total quantity of from 0.003 to 0.15% by weight based on weight of product, an amount of emulsifier of 15% by weight, + 5% based on the combined weight of vehicle and additives, will generally be effective, depending on the particular emulsifiers employed and operation parameters. Useful emulsifiers include those well-known in the art for use with fiber lubricants, especially alkoxylated (usually ethoxylated) C₈-C₁₈-fatty acids, C₈-C₁₈-alcohols, and C₈-C₁₈- alkyl phenols.

The low-sling lubricant of the invention advantageously (and preferably, in many applications) includes a minor amount of additional optional ingredients, particularly antistatic agents to reduce static charge build-up on fibers during processing, corrosion inhibitors to protect vulnerable machine component parts, perfumes, and wetting agents, all of which are selected from conventional fiber lubricant additives known to perform such functions; additives which promote lubricant distribution on the fiber substrate are particularly useful. A small percentage (usually below 1%) water may be present in the formulation.

Typical lubricant products according to the invention are those having the following concentrations (percentages are expressed in percent by weight based on total weight of composition) : RANGE OF

CONCENTRATION

INGREDIENTS (Wt %)

Mineral Oil (80-100 SUS) 78-90

Polymer components a) + b) 0.003-0.15

Emulsifiers 5.0-20

Water 0-1.0

Optional ingredients 0-7.0 (perfume, wetting agent, corrosion inhibitor, antistatic agent, or comparable ingredient)

Preferably at least 80% of the lubricant by weight comprises the mineral oil vehicle.

Lubricant viscosity is chosen to optimize lubricant characteristics in the particular application contemplated; excessively low lubricant tackiness, which exacerbates misting and oil sling tendencies, and excessively high lubricant tackiness, which tends to increase friction and fiber drag, are to be avoided. After the appropriate lubricant viscosity for the application is determined (usually over a range of 10 SUS) the oil vehicle is selected accordingly. In usual practice, a vehicle comprising a single oil or a blend of oils having a vehicle viscosity of from 5 to 50 SUS lower than the desired product viscosity is initially selected; incorporation of the polymer additives then substantially increases the viscosity of this admixture above the desired product viscosity, with the degree of increase dependent upon the amount of additives and polymer number average molecular weight. Admixture viscosities of from 5 to 30 SUS above final product viscosities are typical. Viscosity of the admixture is then reduced by the controlled application of gentle shear forces to the shear-sensitive admixture until the desired final product viscosity is obtained. This controlled-shear method surprisingly provides a product having oil sling characteristics superior to products obtained by customary processes wherein an oil vehicle and polymer additive are merely randomly combined to provide a predetermined product viscosity. Tackiness of the product and accompanying oil sling characteristics are thus primarily a function of vehicle viscosity, polymer number average molecular weight and concentration, and amount of shear applied to the shear-sensitive lubricant ingredients. It is generally advisable to start with a polymer concentration at the low end of the specified range, and increase polymer content as necessary to improve tack and compensate for adverse processing conditions; vehicle viscosity and application of shear forces can then also be adjusted, if necessary, to improve tack. A useful laboratory tack test, albeit subjective, is to obverse lubricant droplets sliding off the end of a glass stirring rod, and to increase or decrease tackiness of the lubricant, as conditions dictate, by increasing or decreasing concentration of the polymers. Generally, a final product viscosity of from 50 to 200 SUS at 100°F, preferably 60 to 100 SUS, will prove satisfactory in combination with the disclosed parameters of polymer types and amounts and vehicle viscosity for a broad range of applications.

The lubricants according to the invention are strictly compounded under low shear conditions to substantially maintain polymer integrity and thereby preserve product characteristics. In particular, it has been found to be critical to avoid shear of sufficient force to disrupt polymer integrity during product handling, especially during formulation of the composition. Mechanical pumping of the product, including pumping in process recirculation systems, is to be avoided after addition of the polyisobutylene components. In an exemplary procedure, the emulsifier is added to the mineral oil under normal agitation, followed by addition of optional ingredients and water while continuing agitation. After mixing is complete (several minutes are usually required, depending upon bulk quantity rate of agitation, and mixing equipment) , agitation is stopped pending charging of the isobutylene polymer or copolymer additives (pre-dissolved in oil vehicle) . Agitation is then restarted and the ingredients mixed under mild agitation for another several minutes until properly combined and the desired viscosity achieved. The viscosity of the batch is periodically checked to ensure conformance to specification. As previously noted, a final viscosity of from 50 SUS to 200 SUS, preferably 60 to 100 SUS is generally acceptable for most applications. The product is shipped, critically without application of substantial shear forces, such as by filtration or mechanical pumping, after additive compounding. Exemplary mixing times (based on 5500 gallon quantities, standard equipment, mild agitation) are 10 minutes for the initial agitation (before isobutylene polymers addition) , and 30 minutes (after isobutylene polymers addition) . The low-sling lubricant product is particularly suitable for use on man-made fibers, especially nylon and polyester, in textile operations involving yarn speeds in excess of 700 meters/minute, and particularly in excess of 800 meters/minute. Textured yarns are particularly contemplated. The lubricant is formulated to a tackiness which optimizes lubricant characteristics in a particular application, and is applied to the fiber or other substrate by usual means (for example, by air pump) while avoiding shear forces on the lubricant. The product permits a broad range of applications of lubricant in textile operations without tedious extensive trial-and-error adjustments for each process, and permits maximization of equipment use by allowing high yarn velocities without concomitant oil splash and workplace hazards. Under the ultra high speed winding operations contemplated according to the invention, the present fiber lubricants will function to reduce lubricant sling to very low levels over a broad range of conditions.

The invention will be illustrated but not limited by the following examples. Example 1

A. Composition

CONCENTRATION (wt % based on

INGREDIENTS total weight) mineral oil (50 SUS) 86.22 polyisobutylene (M.W. 5,000,000)' 1.00 polyisobutylene (M.W. 1,500,000)^* 0.50

Cg.,₀ alcohol phosphate 0.50

C₁₂.₁₄ alcohol ^• 3E0 7.00 monyl phenol ^• 6E0 2.50

PEG 400 monooleate 1.50

50 cs silicone 0.10 perfume 0.04

45% KOH 0.32 water 0.32

¹ 5% polyisobutylene in 95% 50 SUS mineral oil.

A mixer was cleaned and dried, and charged with the mineral oil vehicle. After agitation was begun, each of the remaining ingredients was charged in the sequence listed, except for the water and polyisobutylene additives. The mix was then heated to 100° to 105°F, and then carefully weighed water was then added. This initial mix was continued for 15 minutes, and then agitation stopped. The polyisobutylene additives were then charged, and mild agitation restarted and continued for 30 minutes at 100° to 105°F. The product was removed to shipping containers.

B. The product lubricant from Example IA was applied to a textured polyester yarn which was processed on equipment wherein yarn spends of 870 m/minute were employed. Typical lubricant add-on levels for the yarn were 4.0 ± 0.5%. The results were rated as superior, with almost no oil sling being observed. Example 2

The composition of Example 1 was compounded as described in Example IA except that 0.50% of polyisobutylene (M.W. 5,000,000) and 1.00% of polyisobutylene (M.W. 1,500,000) was used (5% polyisobutylene solutions in 95% SUS mineral oil) .

The results obtained in accordance with Example IB were rated as good, with very little oil sling observed. Example 3

The composition of Example 1 was compounded as described in Example IA except that 0.1% of a copolymer of

75% by wt. isobutylene and 25% by wt. of 1-decene (M.W.

5,000,000) was used instead of the 1.00% polyisobutylene

(M.W. 5,000,000) additive.

The results obtained in accordance with Example IB were rated as superior, with almost no oil sling being observed. Comparative Example 1

The composition of Example 1 was compounded as described in Example IA except that no polyisobutylene (M.W. 1,500,000) was used in the composition.

The results obtained in accordance with Example IB were rated as moderate, i.e. moderate oil sling was observed. Comparative Example 2

The composition of Example 1 was compounded as described in Example IA except that no polyisobutylene (M.W. 5,000,000) additive was present, and 1.00% of polyisobutylene (M.W. 1,500,000) additive was used instead of 0.50%.

The results obtained in accordance with Example IB were rated as poor, with a large and unacceptable quantity of oil sling being observed.

Claims

Claims 1. A low-sling, high tack fiber lubricant having a final viscosity of from 50 SUS to 200 SUS characterized in that the lubricant contains: (a) a mineral oil vehicle having a viscosity of from 40 to 200 SUS in an amount of from 78 to 90% by weight based on the weight of the lubricant;

(b) a high molecular weight oil-soluble polymer having a number average molecular weight in the range of from 3,500,000 to 7,500,000, preferably from 5,000,000 to 6,000,000, selected from one or more of the following:

(i) polyisobutylene homopolymer, (ii) a homopolymer of a straight chain alpha- monoolefin having 4 to 20 carbon atoms, or a copolymer of two or more of such monoolefins, and

(iii) a copolymer of isobutylene and a straight chain alpha-monoolefin having 4 to 20 carbon atoms in which the isobutylene is present in from 10 to 99% by weight;

(c) a low molecular weight oil soluble polyisobutylene homopolymer having a number average molecular weight in the range of from 500,000 to 3,000,000, preferably from 1,000,000 to 2,000,000;

(d) an emulsifier or mixture of emulsifiers in an amount sufficient to stabilize and homogenize the lubricant and to render the lubricant scourable; wherein the ratio by weight of component (b) to component (c) is from 9:1 to 1:9, preferably from 1:2 to 2:1; wherein said lubricant is prepared by a process comprising steps (a) , (b) , and (c) ; (a) selecting a mineral oil vehicle having a viscosity from about 5 to 50 SUS lower than the final viscosity of the lubricant, (b) admixing components (b) , (c) and (d) into the mineral oil vehicle to provide an admixture having a viscosity of from about 5 to 30 SUS above the final viscosity of the lubricant, and (c) applying controlled low shear force to the admixture containing the polyisobutylene additive to reduce viscosity of the admixture to the final viscosity of the lubricant while substantially maintaining polymer integrity; and wherein all viscosity measurements are in SUS at 37.8°C.

2. The lubricant of claim 1 wherein the em"lsifier or emulsifiers is present in an amount of fr 5 to 20%, preferably 10 to 18% by weight based on tts weight of the lubricant.

3. The lubricant of claim 1 or 2 wherein the mineral oil vehicle comprises at least 80% by weight of the composition.

4. The lubricant of claim 1, 2 or 3 wherein from 0.003% to 0.15% of components (b) plus (c) are present therein.

5. In a textile operation method of the type wherein a yarn attains a speed of at least about 700 meters/minute during processing, the improvement characterized by applying a fiber lubricant according to claim 1 to the yarn before it is moved at said speed to substantially reduce lubricant sling from the yarn.

6. The method of claim 5 wherein the yarn comprises one or more synthetic fibers, preferably polyester or nylon.

7. A method for preparing the low-sling, high-tack fiber lubricant of claim 1 characterized in that the process is carried out by:

(a) admixing (i) a mineral oil vehicle having a viscosity from about 40 to 200 SUS and from about 5 to 50 SUS lower than the final viscosity of the lubricant, (ii) an emulsifier or mixture of emulsifiers in an amount sufficient to stabilize and homogenize the lubricant and render it scourable, and (iii) components (b) and (c) of claim 1 to provide an admixture having a viscosity of from about 5 to 30 SUS above the final viscosity of the lubricant; and

(b) applying controlled low shear forces to the admixture containing the polymer additives to reduce the viscosity thereof to the final viscosity of the lubricant and provide a lubricant containing from about 78% to 90% by weight mineral oil vehicle, from about 0.003% to

0.15% by weight of components (b) plus (c) , and having a final viscosity of from about 50 to 200 SUS; wherein the percentages are based on the weight of the lubricants and the viscosities are in SUS at 37.8°C.

8. The method of claim 7 wherein the mineral oil vehicle and emulsifier are first admixed under normal shear conditions, and the polymer additives are admixed with the mineral oil vehicle and emulsifier admixture under said controlled low-shear conditions.