Pressure-sensitive adhesive tape
A pressure-sensitive adhesive tape that uses, as a plasticizer, an alternative compound to bis(2-ethylhexyl) phthalate (DOP) and dibutyl phthalate (DBP), having excellent tackiness, and can be unwound satisfactorily, where DOP and DBP are to be restricted under the REACH regulation. The pressure-sensitive adhesive tape includes a poly(vinyl chloride) substrate and a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer is disposed on or over one side of the substrate. The poly(vinyl chloride) substrate contains 10 to 40 percent by weight of bis(2-ethylhexyl) terephthalate. The pressure-sensitive adhesive tape preferably has an unwinding force of 0.4 N/20 mm or less at a tensile speed of 0.3 m/min and an unwinding force of 1.2 N/20 mm or less at a tensile speed of 30 m/min.
1. A pressure-sensitive adhesive tape comprising:
a poly(vinyl chloride) substrate comprising 10 to 40 percent by weight of bis(2-ethylhexyl) terephthalate;
a pressure-sensitive adhesive layer disposed on or over one side of the substrate; and
a backing-agent layer on or over the other side of the poly(vinyl chloride) substrate opposite to the pressure-sensitive adhesive layer,
wherein the pressure-sensitive adhesive tape has an unwinding force of 0.4 N/20 mm or less at a tensile speed of 0.3 m/min and an unwinding force of 1.2 N/20 mm or less at a tensile speed of 30 m/min, as measured in conformity to Japanese Industrial Standard (JIS) Z 0237:2000.
2. The pressure-sensitive adhesive tape according to claim 1 , wherein the poly(vinyl chloride) substrate has a total content of bis(2-ethylhexyl) phthalate and dibutyl phthalate of 5000 ppm or less.
3. The pressure-sensitive adhesive tape according to claim 2 , wherein the poly(vinyl chloride) substrate comprises 20 to 30 percent by weight of bis(2-ethylhexyl)terephthalate;
the pressure-sensitive adhesive layer comprises a (meth)acrylic pressure-sensitive adhesive comprising a (meth)acrylic polymer B having a solubility parameter (SP) of from 8.9 to 9.4 (cal/cm 3 ) 0.5 as determined by Small's formula as a base polymer;
a monomer component B constituting the (meth)acrylic polymer B includes at least one of methyl methacrylate, acrylic acid, vinyl acetate or acrylonitrile;
a total content of methyl methacrylate, acrylic acid, vinyl acetate and acrylonitrile is from 1 to 50 percent by weight based on 100 percent by weight of the monomer component B;
the backing-agent layer includes a release agent and a resin;
the release agent includes at least one of a silicone resin or a long-chain alkyl acrylate (co-)polymer, and the resin includes at least one of a (meth)acrylic polymer or an ethylene-vinyl acetate copolymer; and
the pressure-sensitive adhesive tape has an unwinding force of 0.32 N/20 mm or less at a tensile speed of 0.3 m/min and an unwinding force of 1.0 N/20 mm or less at a tensile speed of 30 m/min, as measured in conformity to Japanese Industrial Standard (JIS) Z 0237:2000.
4. The pressure-sensitive adhesive tape according to claim 1 , wherein the pressure-sensitive adhesive layer comprises
a (meth)acrylic pressure-sensitive adhesive comprising, a (meth)acrylic polymer B as a base polymer, the (meth)acrylic polymer B having a solubility parameter (SP) of from 8.8 to 9.7 (cal/cm 3 ) 0.5 as determined by Small's formula.
5. The pressure-sensitive adhesive tape according to claim 4 , wherein the (meth)acrylic polymer B comprises, as a monomer component, a monomer capable of forming a homopolymer having a glass transition temperature of 20° C. or higher.
6. The pressure-sensitive adhesive tape according to claim 4 , wherein the (meth)acrylic polymer B in the pressure-sensitive adhesive layer has a solubility parameter (SP) of 8.9 to 9.4 (cal/cm 3 ) 0.5 .
7. The pressure-sensitive adhesive tape according to claim 6 , wherein the pressure-sensitive adhesive layer includes bis(2-ethylhexyl)terephthalate.
8. The pressure-sensitive adhesive tape according to claim 1 , further comprising a separator on or over the pressure-sensitive adhesive layer.
9. The pressure-sensitive adhesive tape according to claim 1 , wherein the pressure-sensitive adhesive layer includes bis(2-ethylhexyl)terephthalate.
10. The pressure-sensitive adhesive tape according to claim 9 , wherein the backing-agent layer includes a release agent and a resin.
11. The pressure-sensitive adhesive tape according to claim 9 , wherein the backing-agent layer includes a silicone resin and a (meth)acrylic polymer.
12. The pressure-sensitive adhesive tape according to claim 9 , wherein the backing-agent layer includes an ethylene-vinyl acetate copolymer and a long-chain alkyl acrylate (co-)polymer.
13. The pressure-sensitive adhesive tape according to claim 9 , wherein a weight ratio of the release agent to the resin is from 1:5 to 3:1.
14. The pressure-sensitive adhesive tape according to claim 9 , wherein the backing-agent layer has an arithmetic mean surface roughness Ra of from 0.5 to 2.0 μm.
15. The pressure-sensitive adhesive tape according to claim 1 , wherein the backing-agent layer includes a release agent and a resin.
16. The pressure-sensitive adhesive tape according to claim 1 , wherein the backing-agent layer includes a silicone resin and a (meth)acrylic polymer.
17. The pressure-sensitive adhesive tape according to claim 1 , wherein the backing-agent layer includes an ethylene-vinyl acetate copolymer and a long-chain alkyl acrylate (co-)polymer.
18. The pressure-sensitive adhesive tape according to claim 1 , wherein a weight ratio of the release agent to the resin is from 1:5 to 3:1.
19. The pressure-sensitive adhesive tape according to claim 1 , wherein the backing-agent layer has an arithmetic mean surface roughness Ra of from 0.5 to 2.0 μm.
20. A pressure-sensitive adhesive tape roll comprising the pressure-sensitive adhesive tape according to claim 1 , the pressure-sensitive adhesive tape being wound as a roll.