A protective film 10 of the present invention includes a base material layer and a pressure sensitive adhesive layer, and is used by being attached to a resin substrate 21 at the time of performing heat bending on the resin substrate 21. The pressure sensitive adhesive layer contains a polyolefin having a melting point of lower than 125° C. The base material layer has a first layer which contains a polyolefin having a melting point of 150° C. or higher, and a second layer which contains an adhesive resin. In a case of heating the protective film 100 having such a configuration, in a state of being interposed between two attaching substrates which are formed of polycarbonate, at 145° C. for 30 minutes, peeling off one attaching substrate on the side of the pressure sensitive adhesive layer at 25° C., and then viewing a surface of the one attaching substrate in a plan view, a residual ratio of an area where the pressure sensitive adhesive layer remains is 5% or less.

An adhesive composition made from an elastomer and a tackifying resin. The tackifying resin includes a farnesene polymer or copolymer having the following properties: i) less than 10 weight percent of volatile organic compounds; ii) Mn between 300 Da and 1000 Da; iii) Mw between 400 Da and 3000 Da; iv) Mw/Mn between 1.00 and 3.00; v) Tg between −50° C. and 20° C.; and vi) viscosity between 400,000 cP and 1,000,000 cP at 25° C. A method of making the farnesene-based polymer or copolymer includes combining a farnesene monomer and a solvent and optionally adding one or more co-monomers selected from dienes, branched mono-olefins, and vinyl aromatics, to provide a monomer feed, and polymerizing the monomer feed by combining it with a Friedel-Crafts initiator in a vessel. The farnesene-based polymer or copolymer tackifier may be combined with one or more elastomers and one or more other tackifiers to form an adhesive composition.

An adhesive composition made from an elastomer and a tackifying resin. The tackifying resin includes a farnesene polymer or copolymer having the following properties: i) less than 10 weight percent of volatile organic compounds; ii) Mn between 300 Da and 1000 Da; iii) Mw between 400 Da and 3000 Da; iv) Mw/Mn between 1.00 and 3.00; v) Tg between −50° C. and 20° C.; and vi) viscosity between 400,000 cP and 1,000,000 cP at 25° C. A method of making the farnesene-based polymer or copolymer includes combining a farnesene monomer and a solvent and optionally adding one or more co-monomers selected from dienes, branched mono-olefins, and vinyl aromatics, to provide a monomer feed, and polymerizing the monomer feed by combining it with a Friedel-Crafts initiator in a vessel. The farnesene-based polymer or copolymer tackifier may be combined with one or more elastomers and one or more other tackifiers to form an adhesive composition.

One aspect of the present invention relates to a method for producing a hot-melt adhesive, comprising: introducing a fluid into a heating kneader while or after kneading a hot-melt adhesive material in a liquid state, at an amount of 0.3 parts by mass or more with respect to 100 parts by mass of the hot-melt adhesive material; and performing vacuuming while heating stirring or dispersing the hot-melt adhesive material and the fluid so as to come into contact with each other.

The object of the present invention is to provide an alkali-dispersible hot melt pressure-sensitive adhesive which (i) has a high alkali-dispersibility, (ii) is excellent in strength to retain the label, (iii) hardly causes an adhesive residue problem and (iv) is capable of reducing stringing. The present invention relates to an alkali-dispersible hot melt pressure-sensitive adhesive comprising: (A) a thermoplastic block copolymer which is a copolymer of a vinyl-based aromatic hydrocarbon and a conjugated diene compound, (B) a tackifier resin and (C) at least one selected from the group consisting of a fatty acid and a derivative thereof, wherein the thermoplastic block copolymer (A) comprises (A1) a styrene-based block copolymer having a styrene content of less than 40 mass % and the tackifier resin (B) comprises an α-methylstyrene-based resin.

The object of the present invention is to provide an alkali-dispersible hot melt pressure-sensitive adhesive which (i) has a high alkali-dispersibility, (ii) is excellent in strength to retain the label, (iii) hardly causes an adhesive residue problem and (iv) is capable of reducing stringing. The present invention relates to an alkali-dispersible hot melt pressure-sensitive adhesive comprising: (A) a thermoplastic block copolymer which is a copolymer of a vinyl-based aromatic hydrocarbon and a conjugated diene compound, (B) a tackifier resin and (C) at least one selected from the group consisting of a fatty acid and a derivative thereof, wherein the thermoplastic block copolymer (A) comprises (A1) a styrene-based block copolymer having a styrene content of less than 40 mass % and the tackifier resin (B) comprises an α-methylstyrene-based resin.

A protective film of the present invention is used at the time of performing heat bending on the resin substrate, and includes a base material layer and a pressure sensitive adhesive layer adhered to a resin substrate, in which the base material layer includes a first layer which is positioned on an opposite side of the pressure sensitive adhesive layer and has a melting point of 150° C. or higher, and includes a second layer which is positioned on a pressure sensitive adhesive layer side and has a melting point of lower than 150° C., the pressure sensitive adhesive layer has a melting point of lower than 150° C., and MFR of a thermoplastic resin contained in the second layer, which is measured in conformity with JIS K7210, is in a range of 0.5 g/10 min to 4.0 g/10 min.

A block copolymer including a polymer block (A) containing more than 70 mol % of a unit derived from an aromatic vinyl compound, and a polymer block (B) containing 30 mol % or more of a unit derived from a conjugated diene compound is provided. The block copolymer satisfies the conditions: (1): a content of the polymer block (A) in the block copolymer is 1 to 70% by mass; (2): a maximum width of a series of temperature regions where tan δ measured in accordance with JIS K7244-10 (2005), under conditions including a strain amount of 0.1%, a frequency of 1 a measurement temperature of −70 to 100° C., and a temperature rise rate of 3° C./min, is 1.0 or more is less than 16° C.; (3): a temperature at a peak position of tan δ in the condition (2) is 0° C. to +50° C.; and (4): a mobility parameter M indicating a mobility of the polymer block (B) is 0.01 to 0.25 sec.

A block copolymer including a polymer block (A) containing more than 70 mol % of a unit derived from an aromatic vinyl compound, and a polymer block (B) containing 30 mol % or more of a unit derived from a conjugated diene compound is provided. The block copolymer satisfies the conditions: (1): a content of the polymer block (A) in the block copolymer is 1 to 70% by mass; (2): a maximum width of a series of temperature regions where tan δ measured in accordance with JIS K7244-10 (2005), under conditions including a strain amount of 0.1%, a frequency of 1 a measurement temperature of −70 to 100° C., and a temperature rise rate of 3° C./min, is 1.0 or more is less than 16° C.; (3): a temperature at a peak position of tan δ in the condition (2) is 0° C. to +50° C.; and (4): a mobility parameter M indicating a mobility of the polymer block (B) is 0.01 to 0.25 sec.

A tackifier composition comprising at least one thermoplastic hydrocarbon resin and an antioxidant composition is provided; wherein a portion of the volatile organic compounds in the thermoplastic hydrocarbon resin has been removed; wherein the antioxidant composition comprises at least one primary antioxidant and at least one secondary antioxidant; and wherein the levels of individual volatile organic compound monitored in the tackifier composition are less than about 0.5 ppm as measured by GC/MS headspace analysis. Processes for producing the tackifier composition are also provided as well as adhesives comprising the tackifier compositions.