Phenolic resin foam and method for producing the same

1. A phenolic resin foam comprising a hydrocarbon component, and having a density of 10kg/m 3 to 150kg/m 3 , wherein

in the phenolic resin foam, the hydrocarbon component comprises 40 mol % to 90 mol % of cyclopentane and 60 mol % to 10 mol % of one or more types selected from hydrocarbons different than cyclopentane that have a carbon number of 6 or less and a boiling point of −50° C. to 5° C.,

the average boiling point X of the hydrocarbon component is 5° C. to 44° C. and the content Y of the hydrocarbon component in the phenolic resin foam is 0.25 mol to 0.70 mol per 22.4×10 −3 m 3 of space volume contained within the phenolic resin foam, and

the thermal conductivity measured at 10° C. and the thermal conductivity measured at 23° C. of the phenolic resin foam are less than 0.0205W/m·K.

2. The phenolic resin foam according to claim 1 , wherein a coefficient Z is a number from 0.4 to 1.10 when calculated using the following equation (1):

Z =0.0063 X+Y   (1).

3. The phenolic resin foam according to claim 1 , having:

a closed cell ratio of 90% or more;

an average cell diameter of 40 μm to 300 μm; and

a void area ratio of 0.2% or less.

4. The phenolic resin foam according to claim 1 , wherein the hydrocarbon having a boiling point of −50° C. to 5° C. contains isobutane.

5. The phenolic resin foam according to claim 1 , wherein the total amount of cyclopentane and the hydrocarbon having a boiling point of −50° C. to 5° C. among substances having a boiling point of −100° C. to 81° C. contained in the phenolic resin foam is 70 mol % to 100 mol %.

6. The phenolic resin foam according to claim 1 , wherein the total content of compounds having reactivity with an acid curing catalyst or compounds which are altered by the acid curing catalyst is 0.5% by weight or less relative to the phenolic resin foam.

7. A method for producing the phenolic resin foam according to claim 1 , comprising:

mixing a foamable phenolic resin composition containing a phenolic resin, a surfactant, a foaming agent including cyclopentane and a hydrocarbon having a boiling point of −50° C. to 5° C., and an acid curing catalyst with a mixing machine;

discharging the foamable phenolic resin composition from a distribution part of the mixing machine; and then

pressurizing an upper surface and a lower surface of the foamable phenolic resin composition while foaming and curing the foamable phenolic resin composition by heating to produce a phenolic resin foam molded in the form of a plate.

8. The method according to claim 7 , wherein the pressure in the distribution part is 0.3 MPa or more and 10 MPa or less.

9. The method according to claim 7 , wherein

water is contained in the foamable phenolic resin composition to be mixed with the mixing machine in an amount of 2% by weight to 20% by weight, and foaming and curing is performed in a double conveyor at a temperature of 60° C. to 100° C.

10. The method according to claim 9 , wherein

a coefficient R is a number from 20 to 36 when calculated from the content of water P in percentage by weight of the foamable phenolic resin composition and the temperature Q in ° C. in the double conveyor using the following equation (2):

R=P+ 0.2286 Q   (2).

11. The phenolic resin foam according to claim 1 , wherein the average boiling point X of the hydrocarbon component is 15 to 37° C.