Wet lap composition and related processes

a technology of fibers and compositions, applied in the field of waterdispersible fibers and fibrous articles, can solve the problems of not producing articles that are readily disintegrated, not providing fibrous articles, and difficult disposal of personal care products made from conventional thermoplastic polymers, so as to reduce the blocking and fusion of fibers

Inactive Publication Date: 2011-06-16
EASTMAN CHEM CO
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0033]The sulfopolyester has a glass transition temperature of at least 57° C. which

Problems solved by technology

Unfortunately, the personal care products made from conventional thermoplastic polymers are difficult to dispose of and are usually placed in landfills.
The various thermoplastic polymers now used in personal care products are not inherently water-dispersible or soluble and, hence, do not produce articles that readily disintegrate and can be disposed of in a sewerage system or recycled easily.
These approaches, however, suffer from a number of disadvantages and do not provide a fibrous article, such as a fiber or nonwoven fabric, that possesses a satisfactory balance of performance properties, such as tensile strength, absorptivity, flexibility, and fabric integrity under both wet or dry conditions.
The resulting assemblies, however, generally have poor water-responsivity and are not suitable for flushable applications.
The presence of binder also may result in undesirable properties in the final product, such as reduced sheet wettability, increased stiffness, stickiness, and higher production costs.
It is also difficult to produce a binder that will exhibit adequate wet strength during use and yet disperse quickly upon disposal.
Thus, nonwoven assemblies using these binders may either disintegrate slowly under ambient conditions or have less than adequate wet strength properties in the presence of body fluids.
Ion concentrations and pH levels in public sewerage and residential septic systems, however, can vary widely among geographical locations and may not be sufficient for the binder to become soluble and disperse.
Polymers which have good water dispersibility, however, often impart tackiness to the resulting multicomponent fibers, which causes the fiber to stick together, block, or fuse during winding or storage after several days, especially under hot, humid conditions.
Such oil finishes, pigments, and fillers require additional processing steps and can impart undesirable properties to the final fiber.
Many water-dispe

Method used

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  • Wet lap composition and related processes

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0285]A sulfopolyester containing 76 mole %, isophthalic acid, 24 mole % of sodio-sulfoisophthalic acid, 76 mole % diethylene glycol, and 24 mole % 1,4-cyclohexane-dimethanol with an Ih.V. of 0.29 and a Tg of 48° C. was meltblown through a nominal 6-inch die (30 holes / inch in the nosepiece) onto a cylindrical collector using the conditions shown in Table 1. Interleafing paper was not required. A soft, handleable, flexible web was obtained that did not block during the roll winding operation. Physical properties are provided in Table 2. A small piece (1″×3″) of the nonwoven fabric was easily dispersed in both room temperature (RT) and 50° C. water with slight agitation as shown by data in Table 3.

TABLE 1Melt Blowing ConditionsOperating ConditionTypical ValueDie ConfigurationDie tip hole diameter0.0185inchesNumber of holes120Air gap0.060inchesSet back0.060inchesExtruder Barrel Temperatures (° F.)Zone 1350Zone 2510Zone 3510Die Temperatures (° F.)Zone 4510Zone 5510Zone 6510Zone 7510Zone...

example 2

[0286]A sulfopolyester containing 89 mole %, isophthalic acid, 11 mole % of sodiosulfoisophthalic acid, 72 mole % diethylene glycol, and 28 mole % ethylene glycol with an Ih.V. of 0.4 and a Tg of 35° C. was meltblown through a 6-inch die using conditions similar to those in Table 1. A soft, handleable, flexible web was obtained that did not block during a roll winding operation. Physical properties are provided in Table 2. A small piece (1″×2″) of the nonwoven fabric was easily and completely dispersed at 50° C. and 80° C.; at RT (23° C.), the fabric required a longer period of time for complete dispersion as shown by the data in Table 3.

[0287]It was found that the compositions in Examples 1 and 2 can be overblown onto other nonwoven substrates. It is also possible to condense and wrap shaped or contoured forms that are used instead of conventional web collectors. Thus, it is possible to obtain circular “roving” or plug forms of the webs.

example 3

[0293]A circular piece (4″ diameter) of the nonwoven produced in Example 2 was used as an adhesive layer between two sheets of cotton fabric. A Hannifin melt press was used to fuse the two sheets of cotton together by applying a pressure 35 psig at 200° C. for 30 seconds. The resultant assembly exhibited exceptionally strong bond strength. The cotton substrate shredded before adhesive or bond failure. Similar results have also been obtained with other cellulosics and with PET polyester substrates. Strong bonds were also produced by ultrasonic bonding techniques.

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Abstract

A microfiber-containing wet lap composition is provided. The wet lap composition comprises a mixture of a sulfopolyester dispersion and a plurality of water nondispersible synthetic polymer microfibers. The microfibers have an equivalent diameter of less than 5 microns and a length of less than 25 millimeters. The sulfopolyester dispersion comprises at least one sulfopolyester and water.

Description

CROSS REFERENCES TO RELATED APPLICATIONS[0001]This application is a continuation-in-part application claiming priority to application Ser. No. 12 / 199,304, filed Aug. 27, 2008, which is a continuation in part of Provisional Application Ser. No. 61 / 041,699, filed Apr. 2, 2008 and continuation-in-part application application Ser. No. 11 / 648,955 filed Jan. 3, 2007, which is a continuation-in-part of application Ser. No. 11 / 344,320 filed Jan. 31, 2006, which is a continuation-in-part of application Ser. No. 11 / 204,868, filed Aug. 16, 2005, which is a divisional of application Ser. No. 10 / 850,548, filed May 20, 2004, now issued as U.S. Pat. No. 6,989,193, which is a continuation-in-part of application Ser. No. 10 / 465,698, filed Jun. 19, 2003. The foregoing applications are hereby incorporated by reference.FIELD OF THE INVENTION[0002]The present invention pertains to water-dispersible fibers and fibrous articles comprising a sulfopolyester. The invention further pertains to multicomponent ...

Claims

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Application Information

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IPC IPC(8): D21H13/24
CPCD01D5/0985D01D5/36D01F6/84D01F8/14D04H1/4291D21H15/10D04H13/002D21H13/20D21H13/24D21H13/40D04H1/435D21H5/207
Inventor GUPTA, RAKESH KUMARMITCHELL, MELVIN GLENNKLOSIEWICZ, DANIEL WILLIAMCLARK, MARK DWIGHTANDERSON, CHRIS DELBERTMITCHELL, MARVIN LYNNMITCHELL, PAULA HINESWOLFE, AMBER LAYNE
Owner EASTMAN CHEM CO
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