Solid surface materials with polyurethane matrix

Abstract

The present invention relates to polyurethane based solid surface materials with improved dimensional stability which can be made using conventional inorganic fillers without pre-treatment of the fillers.

Claims

1. A polymerizable composition comprising (i) at least one polyol A1 having an OH-content of at least 25 wt.-%, wherein the at least one polyol A1 is selected from the group consisting of glycerol, propanediol, butanediol, 1,2,10-decanetriol, 1,2,8-octanetriol, 1,2,3-trihydroxybenzene, 1,1,1-trimethylolpropane, 1,1,1-trimethylolethane, penthaerythrol and sugar polyols; (ii) at least one polyisocyanate A2 comprising at least 60 wt.-% of aliphatic polyisocyanates; (iii) at least one organic filler B1; (iv) at least one inorganic filler B2, wherein the inorganic filler B2 is not dried and comprises a water content of at least 0.15 wt.-%; and (v) expandable microspheres; wherein the polyol A1 makes up at least 95 wt.-% of all hydroxyl-functional compounds in the polymerizable composition, and wherein the polymerizable composition is for reaction injection molding.

2. The polymerizable composition according to claim 1, wherein the polymerizable composition comprises at least 25 wt.-% inorganic filler B2 based on the total mass of the total mass of the polymerizable composition.

3. The polymerizable composition according to claim 1, wherein the polymerizable composition comprises at least 5 wt.-% organic filler B1 based on the total mass of the polymerizable composition.

4. The polymerizable composition according to claim 1, wherein the polyisocyanate A2 comprises at least 5 wt.-% oligomeric polyisocyanates.

5. The polymerizable composition according to claim 1, wherein the inorganic filler is selected from the group consisting of alumina trihydrate, quartz and dolomite.

6. The polymerizable composition according to claim 1, wherein an upper limit of the water content of the inorganic filler is 5 wt.-%.

7. The polymerizable composition according to claim 1, wherein the organic filler B1 is selected from the group consisting of polyethylene, high density polyethylene, polyvinyl chloride, silicone, polycarbonate, polyamide 11, polyamide 12, thermoplastic polyurethane, polyurea powder and polypropylene.

8. A method comprising utilizing the polymerizable composition according to claim 1 for manufacturing a solid surface material.

9. A solid surface material comprising a) a polyurethane matrix comprising as building blocks (i) at least one polyol A1 having an OH-content of at least 25 wt.-%, wherein the at least one polyol A1 is selected from the group consisting of glycerol, propanediol, butanediol, 1,2,10-decanetriol, 1,2,8-octanetriol, 1,2,3-trihydroxybenzene, 1,1,1-trimethylolpropane, 1,1,1-trimethylolethane, penthaerythrol and sugar polyols; and (ii) at least one polyisocyanate A2 comprising at least 60 wt.-% of aliphatic polyisocyanates; wherein the polyol A1 makes up at least 95 wt.-% of all hydroxyl-functional compounds in the polyurethane matrix; and b) at least one organic filler B1, at least one inorganic filler B2, wherein the inorganic filler B2 is not dried and comprises a water content of at least 0.15 wt.-%, and expandable microspheres, wherein the solid surface material is formed by a reaction molding process.

10. The solid surface material of claim 9, having a density of at least 1000 kg/m.sup.3.

11. A method for manufacturing a solid surface material comprising the steps of a) mixing of (i) at least one polyol A1 having an OH-content of at least 25 wt.-%, wherein the at least one polyol A1 is selected from the group consisting of glycerol, propanediol, butanediol, 1,2,10-decanetriol, 1,2,8-octanetriol, 1,2,3-trihydroxybenzene, 1,1,1-trimethylolpropane, 1,1,1-trimethylolethane, penthaerythrol and sugar polyols, (ii) at least one polyisocyanate A2 comprising at least 60 wt.-% of aliphatic and cycloaliphatic polyisocyanates, (iii) at least one organic filler B1, (iv) at least one inorganic filler B2, wherein the inorganic filler B2 is not dried and comprises a water content of at least 0.15 wt.-%, and (v) expandable microspheres; wherein the polyol A1 makes up at least 80 wt.-% of all hydroxyl-functional compounds in the reaction mixture obtained in method step a); b) filling of the reaction mixture obtained in method step a) into a closed mold; and c) curing of the reaction mixture, wherein the method is a reaction molding process.

12. A solid surface material obtained by the method according to claim 11.

Description

EXAMPLES

(1) Materials:

(2) Desmodur N3600: solvent free HDI based isocyanurate Desmodur XP2489 solvent free HDI/IPDI polyisocyanate

(3) The technical data sheet for alumina trihydride mentions a water content of 0.25% at 105 C. The sample was stored at RT in the laboratory.

Example 1 (Inventive)

(4) 1A Solid Surface Material with Inorganic Fillers

(5) Matrix with Standard Tg:

(6) Desmodur N3600 and glycerol (NCO:OH=1) were mixed with alumina trihydrate with standard mixing equipment to yield a weight ratio of resin to filler of 70:30.0.005 wt.-% of dibutyltin laurate as catalyst were added.

(7) The reaction mixture was injected into a mold (1 cm15 cm10 cm) at a pressure of 5 bar and demolded after 20 minutes.

(8) The reacted solid surface material displayed a glass transition temperature of 103 C.

(9) Matrix with High Tg

(10) Desmodur XP2489 and glycerol (NCO:OH=1) were warmed to 50 C. and mixed with alumina trihydrate with standard mixing equipment to yield a ratio of resin to filler of 70:30.0.005 wt.-% of dibutyltin laurate as catalyst were added.

(11) The reaction mixture was injected into a mold (1 cm15 cm10 cm) at a pressure of 5 bar and demolded after 20 minutes.

(12) The reacted solid surface material displayed a glass transition temperature of 160 C.

(13) The optical evaluation of both products showed an even and homogeneous surface without defects. A cut across the surface showed an homogeneous material without visible bubbles.

Example 2 (Comparative)

(14) Desmodur XP2489, glycerol (NCO:OH=1) and alumina trihydrate were mixed in a speed mixer for 30 seconds at 3500 rpm to yield a ratio of resin to filler of 70:30. The reaction mixture was then filled into an open mold at room temperature.

(15) After curing for 8 hours at 130 C., the material was tested for its optical and mechanical properties. The result was an uneven surface which does not suffice the aesthetics of a common solid surface material. There were open and closed bubbles present in the surface.