Process of manufacturing a water-based adhesive bonded, solvent resistant protective laminate

A process of manufacturing a water-based adhesive bonded, solvent resistant protective laminate comprising:

• providing a temperature-sensitive polyolefin-based, microporous film having a first surface and a second surface, said microporous film having an areal shrinkage of greater than about 5 percent at temperatures greater than about 80 degrees Centigrade;
• depositing a discontinuous coating of a water-based, crosslinkable, carboxylated styrene-butadiene rubber latex adhesive on the first surface of the temperature-sensitive, microporous film, the latex adhesive containing an effective amount of a crosslinking agent;
• joining a fibrous nonwoven web selected from the group consisting of bonded carded webs, spunbonded webs, meltblown fiber webs and combinations thereof, into intimate bonding contact with the temperature-sensitive, microporous film and adhesive to form a laminate;
• and
• removing water from the adhesive to cause crosslinking at reactive sites at temperatures less than about 80 degrees Centigrade;
• resulting in an adhesive bonded, solvent resistant protective laminate having a dry adhesion strength greater than about 120 grams per two inches, measured using ASTM D1876-72.

A nonwoven composite fabric comprising:

• a breathable thermoplastic polyolefin-based film having at least one film surface adhesively bonded to a layer of nonwoven thermoplastic polyolefin material;
• the bonding occurring at multiple spaced apart locations through the agency of a water-based crosslinkable, carboxylated styrene-butadiene latex adhesive material which has been dried at not more than about 100.degree. C. to yield a dry adhesion strength greater than about 120 grams per two inches, measured using ATM D1876-72;
• the breathable film having a thickness of at least about 1.0 mil and an MVTR of greater than about 500 grams/m.sup.2 -24 hours;
• the nonwoven layer including a nonwoven fibrous polyolefin web having a basis weight of about 15-150 grams/m.sup.2.

A nonwoven composite fabric, comprising:

• a microporous thermoplastic polyolefin-based film having at least one film surface adhesively bonded to a layer of nonwoven thermoplastic material;
• the bonding occurring at multiple spaced apart locations through the agency of a water-based crosslinkable, carboxylated styrene-butadiene latex adhesive material which has been dried at not more than about 100.degree. C. to yield a dry adhesion strength greater than about 120 grams per two inches, measured using ASTM D1876-72;
• the microporous film having a thickness of at least about 1 mil and an MVTR of greater than about 500 grams/m.sup.2 -24 hours;
• the nonwoven layer including a spunbond web having a basis weight of at least about 40 grams/m.sup.2.

A process for forming an adhesive bonded nonwoven composite fabric including a continuous thermoplastic breathable polyolefin-based film having a thickness of at least about 1 mil and an MVTR of greater than about 500 grams/m.sup.2 -24 hours, and a continuous thermoplastic polyolefin nonwoven web having a basis weight of about 15-150 grams/m.sup.2, the process comprising:

• unwinding the continuous thermoplastic polyolefin web and the continuous thermoplastic breathable polyolefin-based film;
• inserting a water-based, crosslinkable, carboxylated styrene-butadiene latex adhesive bonding material at multiple spaced apart locations between the continuous thermoplastic polyolefin web and the continuous thermoplastic polyolefin-based film;
• contacting a side of the continuous thermoplastic polyolefin web adjacent to the adhesive bonding material with a side of the continuous thermoplastic polyolefin-based film;
• and
• curing the adhesive by drying it at not more than about 100.degree. C., to yield a dry adhesion strength greater than about 120 grams per two inches, measured using ASTM D1876-72.

A process for forming an adhesive-bonded composite nonwoven fabric including a continuous thermoplastic microporous polyolefin-based film having a thickness of at least about 1 mil and an MVTR of greater than about 500 grams/m.sup.2 -24 hours, and a continuous thermoplastic spunbond web having a basis weight of at least about 40 grams/m.sup.2, the process comprising:

• unwinding the continuous thermoplastic spunbond web and the continuous thermoplastic microporous polyolefin-based film;
• inserting a water-based, crosslinkable, carboxylated styrene-butadiene latex adhesive bonding material at multiple spaced apart locations between the continuous thermoplastic spunbond web and the continuous thermoplastic polyolefin-based film;
• contacting a side of the continuous thermoplastic spunbond web adjacent to the adhesive bonding material with a side of the continuous thermoplastic polyolefin-based film;
• and
• curing the adhesive by drying it at not more than about 100.degree. C., to yield a dry adhesion strength greater than about 120 grams per two inches, measured using ASTM D1876-72.

A nonwoven composite fabric comprising:

• a microporous thermoplastic polyolefin-based film having at least one film surface adhesively bonded to a layer of nonwoven thermoplastic material, the bonding occurring at multiple spaced-apart locations through the agency of a water-based crosslinkable, carboxylated styrene-butadiene rubber latex adhesive material which has been dried at not more than about 100.degree. C. to yield a dry adhesion strength greater than about 120 grams per two inches measured using ASTM D1876-72;
• said composite fabric having a barrier to passage of biological liquid when the composite fabric is subjected to contact with synthetic blood at zero psi for 5 minutes followed by synthetic blood contact at 2 psi (13.6 kPa) for one minute followed by synthetic blood contact at zero psi for fifty-four minutes, said composite fabric exhibiting no visible penetration of synthetic blood;
• said nonwoven composite fabric having a moisture vapor transmission rate of greater than about 450 grams per square meter for twenty-four hours at about 75.degree. F. and about 65% relative humidity;
• and
• said nonwoven composite fabric having a breaking strength of at least about 14 pounds per inch.

A process for forming an adhesive bonded nonwoven composite fabric having a moisture vapor transmission rate of greater than about 240 grams per square meter for 24 hours at about 75.degree. F. and about 65% relative humidity, said fabric providing a barrier to passage of biological liquid when the composite fabric is subjected to contact with synthetic blood at 0 psi for 5 minutes followed by synthetic blood contact at 2 psi (13.6 kPa) for 1 minute followed by synthetic blood contact at 0 psi for 54 minutes, said composite fabric exhibiting no visible penetration of the synthetic blood;

• said composite fabric having a breaking strength of at least 14 pounds per inch;
• said process comprising:
• unwinding at least one continuous thermoplastic nonwoven web and at least one continuous thermoplastic microporous polyolefin-based film;
• inserting a water-based, crosslinkable, carboxylated styrene-butadiene rubber latex adhesive bonding material at multiple spaced-apart locations between the continuous thermoplastic nonwoven web and the continuous thermoplastic microporous film;
• contacting a side of the at least one thermoplastic nonwoven web adjacent to said adhesive bonding material with a side of the continuous thermoplastic microporous film;
• and
• continuously transporting said contacted web and film adjacent to said adhesive bonding material through an adhesive curing zone, said curing zone providing a drying temperature not greater than about 100.degree. C. and dwell time sufficient to cure said adhesive without degrading either the film or web, to yield a dry adhesion strength greater than about 120 grams per two inches, measured using ASTM D1876-72.

A nonwoven composite fabric comprising:

• a microporous thermoplastic polyolefin-based film having at least one film surface adhesively bonded to a layer of nonwoven thermoplastic material, the bonding occurring at multiple spaced-apart locations through the agency of a water-based, crosslinkable, carboxylated styrene-butadiene rubber latex adhesive material which has been dried at not more than about 100.degree. C. to yield a dry adhesion strength greater than about 120 grams per two inches, measured using ASTM D1876-72;
• said composite fabric having a barrier to passage of biological liquid when the composite fabric is subjected to contact with synthetic blood at zero psi for 5 minutes followed by synthetic blood contact at 2 psi (13.6 kPa) for one minute followed by synthetic blood contact at zero psi for fifty-four minutes, said composite fabric exhibiting no visible penetration of synthetic blood;
• the composite fabric providing a barrier to viral penetration when the composite fabric is subject to contact with .O slashed.X174 bacteriophage suspension at a titer of 10.sup.8 PFU/mL for 5 minutes with no applied pressure, 1 minute at 2 psi and 54 minutes with no applied pressure;
• and
• said nonwoven composite fabric having a moisture vapor transmission rate of greater than about 450 grams per square meter for twenty-four hours at about 75.degree. F. and about 65% relative humidity.

A process for forming an adhesively bonded nonwoven composite fabric having a moisture vapor transmission rate of greater than 450 grams per square meter for 24 hours at about 75.degree. F. and about 65% relative humidity, said fabric providing a barrier to passage of biological liquid when the composite fabric is subjected to contact with synthetic blood at 0 psi for five minutes followed by synthetic blood contact of 2 psi (13.6 kPa) for 1 minute followed by synthetic blood at 0 psi for 54 minutes, said composite fabric exhibiting no visible penetration of the synthetic blood;

• said composite fabric providing a barrier to viral penetration when the composite is subject to contact with .O slashed.X174 bacteriophage suspension at a titer of 10.sup.8 PFU/mL for five minutes with no applied pressure, one minute at 2 psi and fifty-four minutes with no applied pressure;
• said process comprising:
• unwinding at least one continuous thermoplastic non-woven web and at least one continuous thermoplastic microporous polyolefin-based film;
• inserting a water-based, crosslinkable, carboxylated styrene-butadiene rubber latex adhesive bonding material at multiple spaced apart locations between the continuous thermoplastic nonwoven web and the continuous thermoplastic microporous film;
• contacting a side of the at least one thermoplastic nonwoven web adjacent to said adhesive bonding material with a side of the continuous thermoplastic microporous film adjacent to said adhesive bonding material;
• and
• continuously transporting said contacting web and film adjacent to said adhesive bonding material through an adhesive bonding zone providing a drying temperature not greater than about 100.degree. C. and a dwell-time sufficient to cure said adhesive without degrading either the film or web, to yield a dry adhesion strength greater than about 120 grams per two inches, measured using ASTM D1876-72.