Paint film protection sheet

Patent metadata

Field	Value
Publication number	US-9902876-B2
Application number	US-201313939457-A
Country	US
Kind code	B2
Filing date	Jul 11, 2013
Priority date	Jul 18, 2012
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

The present invention provides a paint film protection sheet comprising a support substrate and a PSA layer placed on the support substrate. The PSA constituting the PSA layer comprises a non-crosslinked rubber-based polymer as a base polymer, a tackifier resin (T H ) having a softening point of 120° C. or above, and a tackifier resin (T L ) having a softening point below 120° C. The mass ratio (T L /T H ) of the tackifier resin (T L ) content relative to the tackifier resin (T H ) content has a value of 1.0 or larger and 30 or less.

First claim

What is claimed is:

1. A paint film protection sheet comprising a support substrate and a pressure-sensitive adhesive layer placed on the support substrate, wherein
the pressure-sensitive adhesive layer is constituted with a pressure-sensitive adhesive comprising a non-crosslinked rubber-based polymer as a base polymer, at least one tackifier resin (T H ) selected from the group consisting of rosin-based resins, terpene-based resins, petroleum resins, phenol resins, alkylphenol resins, xylene resins, alkyd resins, epoxy resins, and hydrogenation products thereof, and having a softening point of 120° C. or above, and a tackifier resin (T L ) having a softening point of 70° C. to below 120° C.,
the mass ratio (T L /T H ) of the tackifier resin (T L ) content relative to the tackifier resin (T H ) content has a value of 1.0 or larger and 30 or less, and
the base polymer is at least one polymer selected from the group consisting of a homopolyisobutylene, a copolymer of isobutylene and normal butylene, and a copolymer of isobutylene and isoprene,
wherein the tackifier resin (T L ) has an SP value of 8.5 or larger.

2. The paint film protection sheet according to claim 1 , wherein the amount of the tackifier resin (T H ) is 0.05 parts by mass or greater relative to 100 parts by mass of the base polymer, the amount of the tackifier resin (T L ) is 0.05 parts by mass or greater relative to 100 parts by mass of the base polymer, and the total amount of the tackifier resin (T H ) and the tackifier resin (T L ) is 1.0 part by mass or less relative to 100 parts by mass of the base polymer.

3. The paint film protection sheet according to claim 2 , wherein a softening point difference between the tackifier resin (T H ) and the tackifier resin (T L ) is 30° C. or more.

4. The paint film protection sheet according to claim 2 , wherein the tackifier resin (T H ) is a rosin-based resin.

5. The paint film protection sheet according to claim 2 , wherein the tackifier resin (T L ) has an SP value of 8.5 or larger.

6. The paint film protection sheet according to claim 2 , wherein the pressure-sensitive adhesive layer has a thickness of 1 μm or larger, but smaller than 10 μm.

7. The paint film protection sheet according to claim 2 exhibiting a holding time of 200 seconds or more in a constant load peel test.

8. The paint film protection sheet according to claim 1 , wherein a softening point difference between the tackifier resin (T H ) and the tackifier resin (T L ) is 30° C. or more.

9. The paint film protection sheet according to claim 8 , wherein the tackifier resin (T H ) is a rosin-based resin.

10. The paint film protection sheet according to claim 8 , wherein the tackifier resin (T L ) has an SP value of 8.5 or larger.

11. The paint film protection sheet according to claim 8 , wherein the pressure-sensitive adhesive layer has a thickness of 1 μm or larger, but smaller than 10 μm.

12. The paint film protection sheet according to claim 8 exhibiting a holding time of 200 seconds or more in a constant load peel test.

13. The paint film protection sheet according to claim 1 , wherein the tackifier resin (T H ) is a rosin-based resin.

14. The paint film protection sheet according to claim 1 , wherein the pressure-sensitive adhesive layer has a thickness of 1 μm or larger, but smaller than 10 μm.

15. The paint film protection sheet according to claim 1 exhibiting a holding time of 200 seconds or more in a constant load peel test.

16. The paint film protection sheet according to claim 1 , wherein a softening point difference between the tackifier resin (TH) and the tackifier resin (TL) is 30° C. or more.

17. The paint film protection sheet according to claim 1 , wherein 70% by mass or greater of a polymeric component in the pressure-sensitive adhesive is an isobutylene-based polymer.

Assignees

• Nitto Denko Corp
• Kansai Paint Co Ltd

Inventors

• Igarashi Takeshi
• Suzuki Toshitaka
• Wakayama Nao
• Hirano Yoshikuni

Classifications

• C09J123/22 Primary

  Copolymers of isobutene; Butyl rubber {; Homo- or copolymers of other iso-olefines} · CPC title

• C09J2203/306

  for protecting painted surfaces, e.g. of cars · CPC title

• C09J7/0214

  Chemistry & Metallurgy · mapped topic

• C08L23/0815

  with aliphatic 1-olefins containing one carbon-to-carbon double bond · CPC title

• Y10T428/265

  1 mil or less · CPC title