This is to provide a multilayer tube excellent in interlayer adhesiveness and durability thereof while maintaining various characteristics such as low temperature impact resistance, bursting pressure strength and flexibility.

In a multilayer tube having at least two kinds of layers and the both layers are adjacent to each other, an aliphatic polyamide composition constituting one of the layers contains an aliphatic polyamide having a ratio of a number of methylene groups to a number of amide groups of a specific value or more and a copolymerized polyamide having a specific unit, and an elastomeric polymer which may contain a constitutional unit derived from an unsaturated compound having a carboxyl group(s) and/or an acid anhydride group(s).

An object of the present invention is to provide a radio wave absorber that has excellent radio wave absorption against oblique incidence, particularly against oblique incidence of radio waves at around 60 GHz. The object can be achieved by a radio wave absorber that has an absorption range with absorption performance of 15 dB or more within the frequency band of 55 to 65 GHz of 4 GHz or more in a circular polarization measurement at 45° incidence.

An object of the present invention is to provide a radio wave absorber having excellent radio wave absorption against oblique incidence, particularly against oblique incidence of radio waves at around 79 GHz. The object can be achieved by a radio wave absorber having characteristic A: an absorption range with absorption performance of 15 dB or more within the frequency band of 75 to 85 GHz of 4 GHz or more in a TM polarization measurement at 45° incidence and/or characteristic B: an absorption range with absorption performance of 15 dB or more within the frequency band of 75 to 85 GHz of 4 GHz or more in a TB polarization measurement at 45° incidence.

Provided is a method for preparing a PSA composition for protecting Low-E glass plates from degradation and corrosion. A PSA composition preparation method is provided for Low-E glass plate protection. The method comprises a step of obtaining an aqueous liquid, and a step of obtaining a polymer-containing liquid comprising the aqueous liquid and a polymer. Here, the aqueous liquid satisfies at least (a) having an electrical conductivity below 300 μS/cm or (b) having a chloride ion concentration below 35 μg/mL.

Provided is a Low-E glass plate protective sheet that can have protective properties for a Low-E glass plate as an object to be protected and can maintain good removability while preventing or inhibiting surface contamination of the object to be protected even when prolongedly adhered thereto. The Low-E glass plate protective sheet is provided. The protective sheet has a PSA layer. The PSA layer comprises at least 95% base polymer by weight.

Provided is a Low-E glass plate protective sheet having excellent long-term reliability. A Low-E glass plate protective sheet is provided. The protective sheet has a PSA layer. The PSA layer has a chloride ion amount of 105 μg or less per gram of PSA, determined by hot water extraction.

Provided is a PSA sheet capable of suitably preventing bubble formation caused by outgassing. This invention provides a PSA sheet comprising a PSA layer that forms an adhesive face. In an aging test where the adhesive face is press-bonded to a glass plate and stored at 50° C. for 24 hours, the PSA sheet has at least 5% post-aging non-bonding area Sa, with Sa defined as the ratio of all areas non-bonding to the glass plate relative to the total area of the adhesive face. The non-bonding areas have parts linearly extending along the adhesive face.

The present invention provides a decorative sheet having excellent work characteristics, weather resistance, and scratch resistance and a decorative material using the same. Disclosed are a decorative sheet including a base material and a surface-protecting layer, wherein at least one of the base material and the surface-protecting layer contains a white pigment, the surface-protecting layer is a cured product of a curable resin composition, and a Martens hardness of the decorative sheet is 9 N/mm.sup.2 or more and 25 N/mm.sup.2 or less; and a decorative material using the same.

A multilayer structure comprising solid layers and defining at least one gap that separates the solid layers to form an alternating pattern of the solid layers and the at least one gap in the structure.

Provided is a PSA sheet capable of suitably preventing bubble formation caused by outgassing. This invention provides a PSA sheet comprising a PSA layer that forms an adhesive face. In an aging test where the adhesive face is press-bonded to a glass plate and stored at 50° C. for 24 hours, the PSA sheet has at least 5% post-aging non-bonding area Sa, with Sa defined as the ratio of all areas non-bonding to the glass plate relative to the total area of the adhesive face. The non-bonding areas have parts linearly extending along the adhesive face.