Heat-curable polymer paste

1. An article comprising a substrate, an electrode formed on the substrate, a LED chip placed on the electrode, and a sealant covering the LED chip, wherein the sealant is made from a heat-curable polymer paste comprising:

(i) 100 parts by weight of a polyester resin having a hydroxyl value of 1 to 10 mgKOH/g and a glass transition point (Tg) of 40 to 120° C.;

(ii) 1 to 30 parts by weight of a crosslinking agent comprising methoxymethyl imino melamine selected from the group consisting of the following (a), (b), (c) and mixture therefore:

and

(iii) 50 to 200 parts by weight an organic solvent,

wherein the heat-curable polymer paste has been heated to form the sealant and wherein the article is a LED device.

2. An article comprising a substrate, a light reflector formed on the substrate, an electrode formed on the light reflector, a LED chip placed on the electrode, and a sealant covering the LED chip, wherein the light reflector is made from the heat-curable polymer paste comprising:

(i) 100 parts by weight of a polyester resin having a hydroxyl value of 1 to 10 mgKOH/g and a glass transition point (Tg) of 40 to 120° C.;

(ii) 1 to 30 parts by weight of a crosslinking agent comprising methoxymethyl imino melamine selected from the group consisting of the following (a), (b), (c) and mixtures thereof:

and

(iii) 50 to 200 parts by weight of an organic solvent; and

(iv) 10 to 65 vol. %, based on the volume of the heat-curable polymer paste, of a white pigment selected from the group consisting of titanium oxide (TiO 2 ), silicon oxide (SiO 2 ), aluminum oxide (Al 2 O 3 ), zirconium oxide (ZrO 2 ), magnesium oxide (MgO), zinc oxide (ZnO), barium sulfate (BaSO 4 ) and mixtures thereof; wherein the heat-curable polymer paste has been heated to form the light reflector and wherein the article is a LED device.

3. The article of claim 2 , wherein the sealant is formed from a heat-curable polymer paste comprising:

(i) 100 parts by weight of a polyester resin having a hydroxyl value of 1 to 10 mgKOH/g and a glass transition point (Tg) of 40 to 120° C.;

(ii) 1 to 30 parts by weight of a crosslinking agent comprising methoxymethyl imino melamine selected from the group consisting of the following (a), (b), (c) and mixtures thereof:

and

(iii) 50 to 200 parts by weight an organic solvent,

wherein the heat-curable polymer paste has been heated to form the sealant.

4. A method of manufacturing a LED device comprising the steps of:

providing a substrate;

forming an electrode on the substrate;

placing a LED chip on the electrode;

applying a heat-curable polymer paste to cover the LED chip; and

heating the applied heat-curable polymer paste to form a sealant;

wherein the heat-curable polymer paste comprises:

(i) 100 parts by weight of a polyester resin having hydroxyl value of 1 to 10 mgKOH/g and glass transition point (Tg) of 40 to 120° C.,

(ii) 1 to 30 parts by weight of a crosslinking agent comprising methoxymethyl imino melamine selected from the group consisting of the following (a), (b), (c) and a mixture thereof

 and

(iii) 50 to 200 parts by weight an organic solvent.

5. The method of manufacturing a LED of claim 4 , wherein molecular weight of the polyester resin is 5,000 to 50,000.

6. The method of manufacturing the LED device of claim 4 , wherein the methoxymethyl imino melamine is (c):

7. The method of manufacturing a polymer layer of claim 4 , wherein the substrate comprises at least glass, ceramic or metal on its surface where the heat-curable polymer paste is applied on.

8. A method of manufacturing a LED device comprising steps of:

preparing a substrate;

applying a heat-curable polymer paste on the substrate;

heating the applied heat-curable polymer paste to form a light reflector;

forming an electrode on the light reflector;

placing a LED chip on the electrode;

forming a sealant to cover the LED chip; and

wherein the heat-curable polymer paste comprises:

(i) 100 parts by weight of a polyester resin having hydroxyl value of 1 to 10 mgKOH/g and glass transition point (Tg) of 40 to 120° C.,

(ii) 1 to 30 parts by weight of a crosslinking agent comprising methoxymethyl imino melamine selected from the group consisting of the following (a), (b), (c) and a mixture thereof

 and

(iii) 50 to 200 parts by weight of an organic solvent; and

(iv) 10 to 65 vol. %, based on the volume of the heat-curable polymer paste, of a white pigment selected from the group consisting of titanium oxide (TiO 2 ), silicon oxide (SiO 2 ), aluminum oxide (Al 2 O 3 ), zirconium oxide (ZrO 2 ), magnesium oxide (MgO), zinc oxide (ZnO), barium sulfate (BaSO 4 ) and mixtures thereof.

9. The method of manufacturing the LED device of claim 8 , wherein the molecular weight of the polyester resin is 5,000 to 50,000.

10. The method of manufacturing the LED device of claim 8 , wherein the methoxymethyl imino melamine is (c):

11. The method of manufacturing the LED device of claim 8 , wherein the substrate comprises at least glass, ceramic or metal on its surface on which the heat-curable polymer paste is applied.