Abstract: Biaxially oriented films from high molecular weight polyethylene are characterized by a gas permeable structure formed from random-arranged microfibrils. The films have coefficients of static friction and kinetic friction of not more than 1.0. The biaxially oriented films are further characterized by service smoothness as well as tensile (tangent) modulus and tensile strength. The films may be used for lamination, filter, or for packaging for moisture absorbers. The biaxially oriented films may be obtained by extracting a hydrocarbon plasticizer from a sheet formed from the high molecular weight polyethylene and a hydrocarbon plasticizer, stretching the resulting sheet to obtain an oriented film having a specific surface area of at least 70 m.sup.2 /g and a fibril structure, and heating the oriented film under a standard length constraint to reduce the oriented film in specific area by at least 20 m.sup.2 /g.

Abstract: Biaxially oriented films from high molecular weight polyethylene are characterized by a gas permeable structure formed from random-arranged microfibrils. The films have coefficients of static friction and kinetic friction of not more than 1.0. The biaxially oriented films are further characterized by service smoothness as well as tensile (tangent) modulus and tensile strength. The films may be used for lamination, filter, or for packaging for moisture absorbers. The biaxially oriented films may be obtained by extracting a hydrocarbon plasticizer from a sheet formed from the high molecular weight polyethylene and a hydrocarbon plasticizer, stretching the resulting sheet to obtain an oriented film having a specific surface area of at least 70 m.sup.2 /g and a fibril structure, and heating the oriented film under a standard length constraint to reduce the oriented film in specific area by at least 20 m.sup.2 /g.

Abstract: Biaxially oriented films from high molecular weight polyethylene are characterized by a gas permeable structure formed from random-arranged microfibrils. The films have coefficients of static friction and kinetic friction of not more than 1.0. The biaxially oriented films are further characterized by service smoothness as well as tensile (tangent) modulus and tensile strength. The films may be used for lamination, filter, or for packaging for moisture absorbers. The biaxially oriented films may be obtained by extracting a hydrocarbon plasticizer from a sheet formed from the high molecular weight polyethylene and a hydrocarbon plasticizer, stretching the resulting sheet to obtain an oriented film having a specific surface area of at least 70 m.sup.2 /g and a fibril structure, and heating the oriented film under a standard length constraint to reduce the oriented film in specific area by at least 20 m.sup.2 /g.

Abstract: The biaxially oriented films of high molecular weight polyethylene is formed and its surface modified to provide a hydrophilic property to the resulting film. The film is prepared by melt-kneading the high molecular weight polyethylene with an ordinarily solid hydrocarbon plasticizer and a raw fabric sheet is formed from the resulting molten mixture. After the hydrocarbon plasticizer is extracted the resulting unstretched sheet is stretched under conditions providing a stretched film having a specific surface area of 70 m.sup.2 /g or more and a fibril structure. This stretched film is then heated under standard length constraint conditions to reduce the specific surface area of the stretched film by at least 20 m.sup.2 /g to obtain a biaxially oriented film of high molecular weight polyethylene.

Abstract: A film-forming and thermocurable vinyl alcohol-substituted acrylamide copolymer consisting essentially of(1) 0 to 20 mole% of a unit of the formula ##STR1## wherein R represents a group selected from the class consisting of alkyl groups with 1 to 7 carbon atoms and aryl groups with 6 to 7 carbon atoms, and n is 0 or 1,(2) 30 to 70 mole% of a unit of the formula ##STR2## wherein n is as defined above, (3) 0 TO 20 MOLE% OF A UNIT OF THE FORMULA ##STR3## wherein R' represents a hydrogen atom or a lower alkyl group, and R is as defined above, and(4) 30 to 70 mole% of a unit of the formula ##STR4## wherein R' is as defined above, R" represents a group selected from the class consisting of alkyl groups with 1 to 18 carbon atoms, cycloalkyl groups with 5 to 6 carbon atoms, hydroxyalkyl groups with 2 to 4 carbon atoms and aryl groups with 6 to 7 carbon atoms, and R"' represents a group selected from the class consisting of a hydrogen atom and the group R",the amount of each unit being based on the total amount in mol