Abstract: A lightweight helmet shell includes an inner shell formed from a porous expanded plastic layer, and an outer shell, in which the outer shell is formed from a compressed fiber sheet having an apparent density of 0.15 to 0.7 g/cc and an impact absorbability of less than 300 G. The lightweight helmet shell has excellent breathability, is lightweight, and has improved impact absorbability.

Abstract: The present invention provides an adhesion enhancer and a polymer composition containing the adhesion enhancer for enhancing the adhesion performance of polymer composition substrates to a primer. The adhesion enhancer of the present invention includes an alcohol, a phenol or another organic compound having a hydroxyl group of the alcohol or phenol and another functional group as supported by a porous material, or a master batch prepared by mixing a polymer with the above organic compound as supported on a porous material. The polymer composition substrate obtained by adding more than 0.5 part by weight of the adhesion enhancer based on 100 parts by weight of the polymer to a normal polymer composition shows good adhesion to a primer having an isocyanate group without a separate process of making a coarse surface of the substrate or an abrasion process using an organic solvent.

Abstract: The present invention provides an adhesion enhancer and a polymer composition containing the adhesion enhancer for enhancing the adhesion performance of polymer composition substrates to a primer. The adhesion enhancer of the present invention includes an alcohol, a phenol or another organic compound having a hydroxyl group of the alcohol or phenol and another functional group as supported by a porous material, or a master batch prepared by mixing a polymer with the above organic compound as supported on a porous material. The polymer composition substrate obtained by adding more than 0.5 part by weight of the adhesion enhancer based on 100 parts by weight of the polymer to a normal polymer composition shows good adhesion to a primer having an isocyanate group without a separate process of making a coarse surface of the substrate or an abrasion process using an organic solvent.