Block copolymer compositions, prepregs, and laminates made therefrom

1. A curable resin composition comprising:

(a) 5 to 99 wt. % of a block copolymer, wherein the block copolymer contains at least an A block and at least one of B, B′, and C block;

wherein each A block is a non hydrogenated poly(acyclic conjugated diene) polymer comprising polymerized units of at least one acyclic conjugated diene;

each B block is a poly(1,3-cyclodiene) homopolymer with a GPC block molecular weight Mp of <25 kg/mol,

each B′ block is a poly(1,3-cyclodiene-co-monoalkenyl arene) copolymer with a GPC block molecular weight Mp of <30 kg/mol,

each C block is a poly(alkenyl arene) polymer or copolymer containing at least one high Tg alkenyl arene unit having a Tg of >100° C., and

the block copolymer has a GPC peak molecular weight Mp of <50 kg/mol before coupling;

the block copolymer has a GPC peak molecular weight Mp multiplied by the A block content weight fraction of >500 g/mol;

(b) from 0.1 to 10 wt. % of a cure initiator; and

c) up to 95 wt. % of one or more additives selected from a multi-functional co-curable additive, a diene based rubber, a halogenated or non halogenated flame retardant, an inorganic or organic filler or fiber, an antioxidant, a adhesion promotor, and a film forming polymer;

wherein the curable resin composition after curing has a gel content of >15%.

2. The curable resin composition of claim 1 , wherein the block copolymer has a GPC peak molecular weight Mp of <35 kg/mol before coupling.

3. The curable resin composition of claim 1 , wherein the block copolymer (a) contains less than 5 wt. % of atoms different from carbon and hydrogen.

4. The curable resin composition of claim 1 , wherein the block copolymer (a) has a DSC Tg>100° C.; and a solution viscosity at 25 wt. % in toluene at 25° C. of <2000 mPa·s.

5. The curable resin composition of claim 1 , wherein

each A block is a polybutadiene block with <50 wt. % of 1, 4 polymerized units;

the B and B′ blocks each independently has a GPC block molecular weight Mp of <9 kg/mol; and

the C block has a GPC block molecular weight Mp of <20 kg/mol.

6. The curable resin composition of claim 1 , wherein:

the cure initiator (b) is a peroxide having a 1-hour half-life temperature of >120° C.; and

the one or more additives is a multi-functional co-curable selected from DVB, BVPE, TAC, TAIC, vinyl functionalized PPE resin, bismaleimide resin, diene-based polymer in liquid state or solid state at room temperature;

wherein the diene-based polymer is selected from polybutadienes, polyisoprenes, butadiene-styrene copolymers, isoprene-styrene copolymers, tri-block copolymers of butadiene-styrene-methacrylate, butadiene-styrene-divinylbenzene, butadiene-styrene-acrylonitrile copolymers, butadiene-styrene-maleic anhydride copolymers and combinations thereof.

7. The curable resin composition of claim 1 , wherein the block copolymer (a) has a solution viscosity at 25° C. at 50 wt. % in xylene of less than 10,000 mPa·s, a dielectric constant Dk at 1 gigahertz of <2.6, and a dielectric loss factor Df at 1 gigahertz of <0.003.

8. The curable resin composition of claim 1 , further comprising up to 15 wt. % of an adhesion promoting polymer selected from a poly(arylene ether), a carboxy-functionalized poly(arylene ether), and a styrene-ethylene/butylene-styrene (SEBS) functionalized with maleic anhydride.

9. A prepreg formed by:

(A) coating a substrate with a solution obtained by dissolving from 5 wt. % to up to 90 wt. % of the curable resin composition to of claim 1 in a solvent, and evaporating the solvent forming a coated substrate;

or

(B) impregnating the curable resin composition of claim 1 , into a substrate forming an impregnated substrate, and heat-pressing the impregnated substrate with or without additional curable resin composition; and

forming the prepreg.

10. The prepreg of claim 9 , wherein in the step (A) the solvent is selected from toluene, xylene, MEK, and mixtures thereof, and wherein the solvent is evaporated from the coated substrate at a temperatures below the activating temperature of the cure initiator (b) in the curable resin composition, or for a sufficient amount of time to limit the curing at a level not reaching gel time, forming the coated substrate.

11. A laminated sheet prepared by layering the prepreg of claim 9 with at least a layer of copper foil on at least a surface of the prepreg under heat-pressing conditions.

12. A copper clad laminate comprising the laminated sheet of claim 11 .

13. A printed circuit board comprising the copper clad laminate of claim 12 .

14. A product comprising the curable resin of claim 1 .

15. A curable resin composition comprising:

(a) 5 to 99 wt. % of a block copolymer, wherein the block copolymer contains at least an A block and at least one of B, B′, and C block;

wherein each A block is a non hydrogenated poly(acyclic conjugated diene) polymer comprising polymerized units of at least one acyclic conjugated diene;

each B block is a poly(1,3-cyclodiene) homopolymer with a GPC block molecular weight Mp of <25 kg/mol,

each B′ block is a poly(1,3-cyclodiene-co-monoalkenyl arene) copolymer with a GPC block molecular weight Mp of <30 kg/mol,

each C block is a poly(alkenyl arene) polymer or copolymer containing at least one high Tg alkenyl arene unit having a Tg of >100° C., and

the block copolymer has a GPC peak molecular weight Mp of <50 kg/mol before coupling;

the block copolymer has a GPC peak molecular weight Mp multiplied by the A block content weight fraction of >500 g/mol;

(b) from 0.1 to 10 wt. % of a cure initiator; and

(c) up to 95 wt. % of one or more additives selected from a multi-functional co-curable additive, a diene based rubber, a halogenated or non halogenated flame retardant, an inorganic or organic filler or fiber, an antioxidant, a adhesion promotor, and a film forming polymer;

wherein the block copolymer has a structure selected from any of: A-B, (A-B-) n X, A-B′, (A-B′-) n X, A-B-A, A-B′-A, A-B-C, A-B′-C, A-C-B, A-C-B′, (B-A-) n X, (B′-A-) n X, B-A-B, B′-A-B′, (A-C-B-) n X, (A-C-B′-) n X, A-C-B-A, A-C-B′-A, A-C, A-C-A, and (A-C-) n X;

n is an integer from 2 to 50 and X is a coupling agent residue.

16. A circuit subassembly, comprising:

a conductive metal layer,

a substrate coated with a curable resin composition, wherein the curable resin composition comprises:

(a) 5 to 99 wt. % of a block copolymer, wherein the block copolymer contains at least an A block and at least one of B or B′ or C block;

wherein each A block is a non hydrogenated poly(acyclic conjugated diene) polymer comprising polymerized units of at least one acyclic conjugated diene;

each B block is a poly(1,3-cyclodiene) homopolymer with a GPC block molecular weight Mp of <25 kg/mol,

each B′ block is a poly(1,3-cyclodiene-co-monoalkenyl arene) copolymer with a GPC block molecular weight Mp of <30 kg/mol,

each C block is a poly(alkenyl arene) polymer or copolymer containing at least one high Tg alkenyl arene unit having a Tg of >100° C., and

the block copolymer has a GPC peak molecular weight Mp of <50 kg/mol before coupling;

the block copolymer has a GPC peak molecular weight Mp multiplied by the A block content weight fraction of >500 g/mol;

(b) from 0.1 to 10 wt. % of a cure initiator; and

(c) up to 95 wt. % of one or more additives selected from a multi-functional co-curable additive, a diene based rubber, a halogenated or non halogenated flame retardant, an inorganic or organic filler or fiber, an antioxidant, a adhesion promotor, and a film forming polymer;

wherein the curable resin composition after curing has a gel content of >15%; and

wherein the circuit subassembly has a dissipation factor (Df) of less than 0.006 at 10 GHz and a dielectric constant (Dk) of less than 3.8 at 10 GHz.

17. The circuit subassembly of claim 16 , wherein the block copolymer (a) in the curable resin has a structure selected from any of: A-B, (A-B-) n X, A-B′, (A-B′-) n X, A-B-A, A-B′-A, A-B-C, A-B′-C, A-C-B, A-C-B′, (B-A-) n X, (B′-A-) n X, B-A-B, B′-A-B′, (A-C-B-) n X, (A-C-B′-) n X, A-C-B-A, A-C-B′-A, A-C, A-C-A, and (A-C-) n X; n is an integer from 2 to 50 and X is a coupling agent residue.

18. The circuit subassembly of claim 16 , wherein the block copolymer (a) in the curable resin has a DSC Tg>100° C.; and a solution viscosity at 25 wt. % in toluene at 25° C. of <2000 cP.