High Performance Reactive Pressure Sensitive Adhesive Composition
Provided herein is a high performance reactive pressure sensitive adhesive (HPR-PSA) formulation which can be compounded and coated on facestock at ambient temperatures. Upon curing by exposing to a high temperature, the HPR-PSA becomes a structural adhesive with superior mechanical performance. This HPR-PSA formulation comprises the unique mixture of the SIS and SB rubber, hydrocarbon and rosin resins tackifiers, and a phenolic derivative curing agent.
1 . An adhesive comprising:
a first rubber comprising a styrene-isoprene-styrene (“SIS”) copolymer,
a second rubber comprising a styrene-butadiene (“SB”) copolymer,
a tackifier comprising a compound selected from the group consisting of a hydrocarbon resin, a rosin resin, and mixtures thereof; and
a curing agent comprising a phenolic resin.
2 . The adhesive of claim 1 , wherein the weight ratio of SIS to SB ranges from 4:1 to 0.25:1.
3 . The adhesive of claim 1 , wherein the curing agent comprises a phenolic derivative and is essentially free of sulfur.
4 . The adhesive of claim 2 , wherein the phenolic derivative comprises bromized phenol formaldehyde.
5 . The adhesive of claim 4 , wherein the bromized phenol formaldehyde is bromized alkyl phenol formaldehyde.
6 . The adhesive of claim 1 , wherein the adhesive comprises from 10 to 50 wt % SIS, based on the total weight of the adhesive.
7 . The adhesive of claim 1 , wherein the adhesive comprises from 10 to 50 wt % SB, based on the total weight of the adhesive.
8 . The adhesive of claim 1 , wherein the weight ratio of the tackifier to the combined SIS and SB copolymers ranges from 0.11:1 to 4:1.
9 . The adhesive of claim 1 , wherein the amount of rosin resin in the adhesive ranges from 0 to 50 wt % based on the total weight of the adhesive.
10 . The adhesive of claim 1 , wherein the amount of hydrocarbon resin in the adhesive ranges from 0 to 50 wt % based on the total weight of the adhesive.
11 . The adhesive of claim 1 , wherein the weight ratio of hydrocarbon resin to rosin resin ranges from 1:0 to 0:1.
12 . The adhesive of claim 1 , wherein the total amount of tackifier ranges from 10 to 75 wt % based on the total weight of the adhesive.
13 . The adhesive of claim 1 , wherein the hydrocarbon resin is selected from the group consisting of aliphatic hydrocarbon having 5 carbon atoms, aromatic hydrocarbon having 9 carbon atoms, dicyclopentadiene, and mixtures thereof.
14 . The adhesive of claim 1 , wherein the rosin resin is selected from the group consisting of glycerol ester, pentaerythritol ester, and mixtures thereof.
15 . The adhesive of claim 1 , wherein the curing agent is a mixture of alkyl phenol formaldehyde and bromized alkyl phenol formaldehyde.
16 . The adhesive of claim 1 , any wherein the amount of curing agent ranges from 1 to 15 wt % based on the total weight of the adhesive.
17 . The adhesive of claim 1 , wherein the curing agent has a methylol content that ranges from 5 wt % to 18 wt % based on the weight of the curing agent.
18 . The adhesive of claim 1 , wherein the adhesive demonstrates a storage modulus of at least 300 Pa at 170° C. before being cured.
19 . The adhesive of claim 1 , wherein the adhesive demonstrates a storage modulus of at least 1800 Pa at 170° C. after being cured at 170° C. for 10 minutes, or the adhesive demonstrates at least a 5-fold increase as compared to the storage modulus before curing.
20 . The adhesive of claim 1 , wherein the adhesive demonstrates a peel strength of at least 8 Newton/inch on stainless steel according to the FINAT-1 (2016) method before curing.
21 . The adhesive of claim 1 , wherein the adhesive demonstrates a shear strength of at least 10,000 minutes on stainless steel according to the FINAT-8 (2016) method before curing.
22 . The adhesive of claim 1 , wherein the adhesive demonstrates a lap shear ranging from 0.05 MPa to 2 MPa on stainless steel before curing.
23 . The adhesive of claim 1 , wherein the adhesive demonstrates a lap shear of at least 1 Mpa on stainless steel after curing.
24 . The adhesive of claim 1 , wherein the adhesive demonstrates a D-shear ranging from 5 to 300 Newton/inch before curing.
25 . The adhesive of claim 1 , wherein the adhesive demonstrates a D-shear ranging from 100-2,000 Newton/inch after curing.
26 . An adhesive solution for coating a facestock comprising:
a first rubber comprising a styrene-isoprene-styrene (“SIS”) copolymer,
a second rubber comprising a styrene-butadiene (“SB”) copolymer,
a tackifier comprising a compound selected from the group consisting of a hydrocarbon resin, a rosin resin, and combinations thereof,
a solvent, and
a curing agent, wherein the curing agent is phenolic resin.
27 . A method of producing an adhesive solution comprising
dissolving in a solvent at a temperature of less than 50° C.
i) a first rubber comprising SIS copolymer, a second rubber comprising a SB copolymer,
ii) a tackifier comprising a compound selected from the group consisting of a hydrocarbon resin, a rosin resin, and combinations thereof,
iii) a curing agent, wherein the curing agent is phenolic resin.
to form an adhesive solution.
28 . The adhesive solution of claim 26 , wherein the adhesive solution comprises between 25 wt % and 75 wt % solvent based on the total weight of the adhesive solution.
29 . The adhesive solution of claim 26 , wherein the adhesive solution demonstrates a viscosity of 100-5000 cps.
30 . The method of claim 27 , further comprising coating a facestock with the adhesive solution and drying the adhesive solution at a temperature of less than 110° C. to produce an adhesive layer on the facestock.
31 . The adhesive solution of claim 26 , wherein the adhesive solution has a solid content ranging from 30 wt % to 75 wt %.
32 . The adhesive solution of claim 26 , wherein the solvent is an aromatic solvent.
33 . A method for producing an adhesive, wherein the method comprises
a) dissolving in a solvent at ambient temperature
i) a first rubber comprising SIS copolymer, a second rubber comprising a SB copolymer,
ii) a tackifier comprising a compound selected from the group consisting of a hydrocarbon resin, a rosin resin, and combinations thereof,
iii) a curing agent, wherein the curing agent is phenolic resin.
to form an adhesive solution,
b) coating a facestock with the adhesive solution, and
c) drying the adhesive solution at a temperature of less than 110° C.,
wherein the SIS and SB copolymers are substantially uncrosslinked.
34 . A label comprising a facestock and an adhesive, wherein the adhesive is coated on the facestock and the adhesive comprises:
a) a first rubber comprising a styrene-isoprene-styrene (“SIS”) copolymer,
b) a second rubber comprising a styrene-butadiene (“SB”) copolymer,
c) a tackifier comprising a compound selected from the group consisting of a hydrocarbon resin, a rosin resin, and combinations thereof, and
d) a curing agent comprising a phenolic resin, and
wherein the SIS and the SB copolymers are substantially uncrosslinked.
35 . The label of claim 33 , wherein the SIS and the SB copolymers are crosslinked to a degree of between 10% to 45% after being cured at 170° C. for 10 min.
36 . A tire label comprising the adhesive of claim 1 , wherein the label is attached to a tire.
37 . A labeled tire comprising a tire and a label comprising the adhesive of claim 1 .