Vibration damping and sound absorbing material and production process thereof
It is an object of the invention to provide a vibration damping and sound absorbing material containing a plant-derived polyol which material largely contributes a decrease of environmental load and has excellent vibration damping and sound absorbing properties, and it is another object of the invention to provide a production process of the material. Specifically, disclosed is a vibration damping and sound absorbing material which is suitably used for cars. A vibration damping and sound absorbing material comprises a polyurethane foam which comprises, as raw materials, a polyol and/or a polymer-dispersed polyol in which polymer fine particles obtainable by polymerizing an unsaturated bond-containing compound are dispersed in a polyol, and water, a catalyst and a polyisocyanate, wherein the polyol comprises (A) a plant-derived polyol produced using a raw material obtainable by a plant.
1. A vibration damping and sound absorbing material comprising a polyurethane foam which comprises, as raw materials, a polyol, water, a catalyst and a polyisocyanate,
wherein the polyol comprises:
(A) a plant-derived polyol having a hydroxyl group value of from 65 to 170 mgKOH/g,
a polyoxyalkylene polyol having a hydroxyl group value of from 15 to 60 mgKOH/g, and
a polymer-dispersed polyol in which polymer fine particles obtained by polymerizing an unsaturated bond-containing compound are dispersed in a polyol,
wherein the plant-derived polyol (A) comprises at least one plant-derived polyol selected from the group consisting of:
(A4) a plant-derived polyester polyol at least having a structure such that a hydroxycarboxylic acid, which comprises a castor oil aliphatic acid containing, as a main component, recinoleic acid obtained from castor oil and/or a hydrogenated castor oil aliphatic acid containing, as a main component, 12-hydroxystearic acid obtained by saturating carbon-carbon double bond in the castor oil aliphatic acid, is condensed in a polyhydric alcohol having 2 to 6 hydroxyl groups in one molecule,
(A5) a polyol obtained by, further, adding lactone to the plant-derived polyester polyol (A4), and
(A6) a polyol obtained by, further, adding a hydroxy carboxylic acid having a primary hydroxyl group to the plant-derived polyester polyol (A4),
wherein a test piece having a thickness of 20 mm obtained by the vibration damping and sound absorbing material has a maximum sound absorbing coefficient, as measured in accordance with a 2 microphone method by ISO10534-2, of from 0.80 to 1.0.
2. The vibration damping and sound absorbing material according to claim 1 wherein the vibration damping and sound absorbing material is used for cars.
3. A process for producing a vibration damping and sound absorbing material comprising a polyurethane foam, which process comprises:
injecting a mixed solution which comprises a polyol, water, a catalyst and a polyisocyanate, into a mold,
reacting and expanding,
curing and releasing from the mold,
wherein the polyol comprises:
(A) a plant-derived polyol having a hydroxyl group value of from 65 to 170 mgKOH/g,
a polyoxyalkylene polyol having a hydroxyl group value of from 15 to 60 mgKOH/g, and
a polymer-dispersed polyol in which polymer fine particles obtained by polymerizing an unsaturated bond-containing compound are dispersed in a polyol,
wherein the plant-derived polyol (A) comprises at least one plant-derived polyol selected from the group consisting of:
(A4) a plant-derived polyester polyol at least having a structure such that a hydroxycarboxylic acid, which comprises a castor oil aliphatic acid containing, as a main component, recinoleic acid obtained from castor oil and/or a hydrogenated castor oil aliphatic acid containing, as a main component, 12-hydroxystearic acid obtained by saturating carbon-carbon double bond in the castor oil aliphatic acid, is condensed in a polyhydric alcohol having 2 to 6 hydroxyl groups in one molecule,
(A5) a polyol obtained by, further, adding lactone to the plant-derived polyester polyol (A4), and
(A6) a polyol obtained by, further, adding a hydroxy carboxylic acid having a primary hydroxyl group to the plant-derived polyester polyol (A4),
wherein a test piece having a thickness of 20 mm obtained by the vibration damping and sound absorbing material has a maximum sound absorbing coefficient, as measured in accordance with a 2 microphone method by ISO10534-2, of from 0.80 to 1.0.
4. The process for producing a vibration damping and sound absorbing material according to claim 3 , wherein the mixed solution is prepared by:
[1] preparing a resin premix by mixing the polyol, water and a catalyst, and
[2] mixing the resin premix prepared in the step [1] with a polyisocyanate.