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US4655877A Expired / Lapsed US ⏱️ 0.0 years remaining

Absorbent web structure

Assignee: Mitsui Chemicals Inc
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Filing: 1985-12-23
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Granted: 1987-04-07
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Expires: 2005-12-23
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Abstract

Abstract An absorbent web structure composed of a mixture of 5 to 50% by weight of short fibers of a thermoplastic resin rendered hydrophilic with a surface-active agent and 95 to 50% by weight of cellulosic fibers, said thermoplastic short fibers being melt-bonded to impart self-supporting property to the web structure; characterized in that (i) said thermoplastic short fibers are rendered hydrophilic by forming an aqueous slurry of the fibers containing a nonionic surface-active agent and then dehydrating the slurry, and (ii) said nonionic surface-active agent has (a) an HLB value of from 2 to 20 and (b) a melting point equal to, or higher than, the temperature of the slurry at the time of the dehydrating treatment described in (i) above.

Inventors

  • 👤 Koji Horimoto
  • 👤 Yoshinori Morita

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 18:40
CPC Classifications
D; D21; D21H; D21H5/00; D21H5/12; D21H5/20; D21H5/202; D21H13/00; D21H13/10; D21H13/12; D21H13/14; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2904; Y10T428/2907; Y10T428/2913; Y10T428/2933; Y10T428/2964; Y10T428/2967; Y10T442/00; Y10T442/60; Y10T442/681

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 185 words
An absorbent web structure obtained by a dry sheet forming process composed of a mixutre of 5 to 50% by weight of short fibers of a thermoplastic resin rendered hydrophilic with a surface acting agent and 95 to 50% by weight by cellulosic fibers, said thermoplastic short fibers being melt-bonded to impart self-supporting property to the web structure; characterized in that (i) said thermoplastic short fibers are composed of flash-spun fibers of an olefin resin and are rendered hydrophilic by forming an aqueous slurry of the fibers containing a nonionic surface-active agent and then dehydrating the slurry at a temperature of the slurry of not more than about 50° C., and (ii) said nonionic surface-active agent has (a) an HLB value of from 2 to 20 and (b) a melting point equal to, or higher than, the temperature of the slurry at the time of the dehydrating treatment in (i) above, and (iii) the time required for water absorption, as determined by J. TAPPI testing methods of said absorbent web structure, is 5 seconds or less after melt-bonding treatment at 140° C. for 5 minutes.
Claim 2
Dependent Claim 185 words
An absorbent web structure obtained by a dry sheet forming process composed of a mixutre of 5 to 50% by weight of short fibers of a thermoplastic resin rendered hydrophilic with a surface acting agent and 95 to 50% by weight by cellulosic fibers, said thermoplastic short fibers being melt-bonded to impart self-supporting property to the web structure; characterized in that (i) said thermoplastic short fibers are composed of flash-spun fibers of an olefin resin and are rendered hydrophilic by forming an aqueous slurry of the fibers containing a nonionic surface-active agent and then dehydrating the slurry at a temperature of the slurry of not more than about 50° C., and (ii) said nonionic surface-active agent has (a) an HLB value of from 2 to 20 and (b) a melting point equal to, or higher than, the temperature of the slurry at the time of the dehydrating treatment in (i) above, and (iii) the time required for water absorption, as determined by J. TAPPI testing methods of said absorbent web structure, is 5 seconds or less after melt-bonding treatment at 140° C. for 5 minutes.
Claim 3
Dependent Claim 33 words
The structure of claim 1 wherein the take-up of the nonionic surface-active agent in the thermoplastic short fibers is about 0.1 to about 5% by weight based on the weight of the fibers.
Claim 4
Dependent Claim 20 words
The structure of claim 1 wherein the nonionic surface-active agent has a melting point of at least about 50° C.
Claim 5
Dependent Claim 15 words
The structure of claim 1 wherein the flash spun fibers are treated with polyvinyl alcohol.

References Cited (Backward Citations)

US3920508A Cited
JPS49109606A Cited
JPS49134903A Cited
JPS5191333A Cited
US4179543A Cited
JPS5388266A Cited
JPS56169900A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-04-06 1990-10-06 1991-04-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-04-06 1994-10-06 1995-04-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-04-06 1998-10-06 1999-04-07 $7700.00 Window Closed / Lapsed

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