A method of preparing a reinforced separator comprising the steps of:—providing a porous support (6) on a pre-wetted casting drum (23);—applying a dope solution (3) including a polymer resin and hydrophilic inorganic particles on a side of the porous support other than the side of the porous support in contact with the pre-wetted casting drum;—performing phase inversion (9, 1) of the applied polymer solution thereby obtaining a reinforced separator; and—removing the reinforced separator (7) from the casting drum; wherein the casting drum is pre-wetted with a non-solvent for the polymer resin.

A method for manufacturing a molded surface fastener may include using, as a synthetic resin forming the molded surface fastener, a thermoplastic resin having a melt flow rate of 20 g/10 min or more and 60 g/10 min or less and a flexural modulus of 1000 MPa or more and 2300 MPa or less. Consequently, an engaging element in which a top end surface of an engaging head portion is flat, and at least a part of a back-side proximal end surface of the engaging head portion has an angle of 70° or more and 110° or less with respect to a height direction of the stem portion can be stably molded, and thus the molded surface fastener that has a high peel strength and a good texture can be obtained.

A method for manufacturing a molded surface fastener may include using, as a synthetic resin forming the molded surface fastener, a thermoplastic resin having a melt flow rate of 20 g/10 min or more and 60 g/10 min or less and a flexural modulus of 1000 MPa or more and 2300 MPa or less. Consequently, an engaging element in which a top end surface of an engaging head portion is flat, and at least a part of a back-side proximal end surface of the engaging head portion has an angle of 70° or more and 110° or less with respect to a height direction of the stem portion can be stably molded, and thus the molded surface fastener that has a high peel strength and a good texture can be obtained.

A method of electrospinning (40) is provided, and an electrospinning device (1; 30). The method comprises (i) holding (41) a liquid comprising a polymer melt or a polymer solution in a container (2), (ii) letting out (42) a stream of the liquid from the container through at least one nozzle (3), (iii) creating (43) a voltage difference between the nozzle (3) and a collecting surface (4), (iv) collecting (44) electro spun material coming from the nozzle (3) so as to form a fibrous structure (8) on the collecting surface (4), and (v) directing (45) a laser beam (13) towards the collecting surface (4) so as to locally remove a part of the fibrous structure (8).

An embodiment can provide a polyamide-imide film and a method for producing same, the film comprising a polyamide-imide polymer formed by polymerizing an aromatic diamine compound, an aromatic dianhydride compound and a dicarbonyl compound, wherein, in an XRD graph with a section in which 2θ=8° to 32° as a baseline, the film shows a peak area of 50% or above around 2θ=23° with respect to a peak area seen around 2θ=15°.

An object is to smoothly obtain, through coating of the surface of a metal roll, a polyvinyl alcohol-based resin film that contains a polyvinyl alcohol-based resin and can be used in a water sealing process, and/or to lower the adhesion force of such film on metal seal bar, etc., during heat sealing. As a solution, a polyvinyl alcohol-based resin film containing components A to C below is provided: A. a polyvinyl alcohol-based resin; B. a plasticizer; and C. one or more types selected from sodium polyoxyethylene alkyl ether acetate, disodium polyoxyethylene alkyl sulfosuccinate salt, N-alkyl-N-methyl-ß-alanine sodium salt, and sodium alkane-1,2-diol acetate salt.

One embodiment may provide a polyamide-imide film which is colorless and transparent while having an adequate level of solubility and excellent mechanical properties, the polyamide-imide film comprising a polyamide-imide polymer formed by polymerizing an aromatic diamine compound, an aromatic dianhydride compound and a dicarbonyl compound, wherein, for a square cross-section of 1 cm×1 cm and a thickness of 30 um to 100 mm, the polyamide-imide film has a dissolution time of 5-60 minutes in 10 ml of dimethylacetamide (DMAc), and for a thickness of 50 mm, the polyamide-imide film has a yellowness of at most 5, a haze of at most 2%, a permeability of at least 85% and a modulus of at least 5.0 GPa.

Provided are a water-soluble film having excellent solubility in water and capable of reducing the stickiness of the contact surfaces to each other at the edges during storage in rolls, a production method thereof, and a package using the water-soluble film. A water-soluble film of the present invention includes a polyvinyl alcohol resin. The water-soluble film satisfies a formula (1) below when amounts of crystalline component are respectively (A1).sub.0, (A1).sub.60, and (A1).sub.180, the amounts being obtained from a spin-spin relaxation curve by .sup.1H pulse NMR measurement of the water-soluble film immediately after, 60 seconds after, and 180 seconds after the water-soluble film is immersed in a mixed solution of deuterated water and deuterated methanol mixed at a volume ratio of 1:1 at 5° C.

[00001]$\begin{array}{cc}\left(\mathrm{Math}1\right)& \\ 0.2<{\left(A1\right)}_{60}/{\left(A1\right)}_0<0.6\mathrm{and}{\left(A1\right)}_{180}/{\left(A1\right)}_0<{\left(A1\right)}_{60}/{\left(A1\right)}_0& \left(1\right)\end{array}$

A water-soluble film is provided that is capable of achieving deformation resistance during pouch storage as well as excellent water solubility of the film and excellent reduction in undissolved residues. A water-soluble film includes a polyvinyl alcohol-based resin, wherein a crystal long period Ds obtained from an X-ray profile obtained by small-angle X-ray scattering measurement in a water/methanol mixed solvent (volume ratio: 2/8) is from 10.0 to 30.0 nm and a rate of increase (DS−Da)/Da of the crystal long period Ds to a crystal long period Da obtained by small-angle X-ray scattering measurement before immersion in the solvent is 30% or more and 130% or less.

Provided are a water-soluble film that causes less deformation of the package during storage, while maintaining excellent solubility in water, and is capable of suppressing the occurrence of tears and the like, a production method thereof, and a package using the water-soluble film. A water-soluble film of the present invention includes a polyvinyl alcohol resin. The water-soluble film has an amount (A1) of crystalline component of 60% or less and an amount (A2) of constrained amorphous component from 10% to 50%, the amounts being obtained from a spin-spin relaxation curve by .sup.1H pulse NMR measurement of the water-soluble film in deuterated methanol. A ratio (A1/A2) of the amount (A1) of crystalline component to the amount (A2) of constrained amorphous component is preferably from 0.1 to 5.