POWDER COATING USED FOR HOUSEHOLD APPLIANCE COILED MATERIAL AND PREPARATION METHOD THEREOF

Abstract

Provided are a powder coating material for household appliance coiled material and a preparation method thereof. The powder coating material comprises: a polyester resin, a curing agent, a silicate, a filler, a pigment, and an auxiliary agent. The powder coating material for the household appliance coiled material not only can meet the requirements of coating processes of the coiled material, but also has excellent performances such as flexibility, T-bend performance, impact resistance and solvent resistance, while satisfying the requirement for the thick coatings of the household appliance coiled material.

Claims

1. A powder coating material for household appliance coiled material, comprising, in parts by weight: 55 to 85 parts of modified polyester resin, 5 to 15 parts of curing agent, 1 to 20 parts of modified silicate, 0 to 35 parts of filler, 0 to 10 parts of pigment, and 0 to 8 parts of auxiliary agent.

2. The powder coating material according to claim 1, wherein the powder coating material comprises: 60 to 85 parts of the modified polyester resin, 7 to 10 parts of the curing agent, 5 to 20 parts of the modified silicate, 15 to 35 parts of the filler, 0.5 to 10 parts of the pigment, and 1 to 8 parts of the auxiliary agent.

3. The powder coating material according to claim 1, wherein the modified polyester resin is an organosilicon modified carboxyl-terminated polyester resin which has an acid value of 35 to 65 mgKOH/g, and an ICI melt viscosity of 3,000 to 6000 mPa.Math.s at a temperature of 200° C.

4. The powder coating material according to claim 1, wherein the modified silicate is a silicate modified by an amino silane coupling agent and maleic anhydride.

5. The powder coating material according to claim 4, wherein the modified silicate is selected from modified porous silicate.

6. The powder coating material according to claim 1, wherein the curing agent comprises at least one selected from beta-hydroxyalkylamide and blocked isocyanate.

7. The powder coating material according to claim 6, wherein the curing agent comprises beta-hydroxyalkylamide and blocked isocyanate.

8. The powder coating material according to claim 1, wherein the filler comprises at least one selected from barium sulfate, silica powder, mica powder, and rutile titanium dioxide: the pigment is selected from outdoor general-purpose pigments; and the auxiliary agent comprises at least one selected from a leveling agent, an antioxidant, a degassing agent, and an air-permeabilizing agent.

9. A method for preparing the powder coating material according to claim 1, comprising: 1) weighing each ingredient in proportion, mixing and crushing, to obtain a mixed material; and 2) extruding the mixed material in an extruder, tableting and crushing, to obtain the powder coating material.

10. The method according to claim 9, wherein the powder coating material has a D50 particle size of 35 to 45 μm.

11. The method according to claim 9, wherein the powder coating material comprises: 60 to 85 parts of the modified polyester resin, 7 to 10 parts of the curing agent, 5 to 20 parts of the modified silicate, 15 to 35 parts of the filler, 0.5 to 10 parts of the pigment, and 1 to 8 parts of the auxiliary agent.

12. The method according to claim 9, wherein the modified polyester resin is an organosilicon modified carboxyl-terminated polyester resin which has an acid value of 35 to 65 mgKOH/g, and an ICI melt viscosity of 3,000 to 6000 mPa.Math.s at a temperature of 200° C.

13. The powder coating material according to claim 9, wherein the modified silicate is a silicate modified by an amino silane coupling agent and maleic anhydride.

14. The powder coating material according to claim 13, wherein the modified silicate is selected from modified porous silicate.

15. The powder coating material according to claim 9, wherein the curing agent comprises at least one selected from beta-hydroxyalkylamide and blocked isocyanate.

16. The powder coating material according to claim 15, wherein the curing agent comprises beta-hydroxyalkylamide and blocked isocyanate.

17. The powder coating material according to claim 9, wherein the filler comprises at least one selected from barium sulfate, silica powder, mica powder, and rutile titanium dioxide; the pigment is selected from outdoor general-purpose pigments; and the auxiliary agent comprises at least one selected from a leveling agent, an antioxidant, a degassing agent, and an air-permeabilizing agent.

Description

DETAILED DESCRIPTION

[0042] The present disclosure is further illustrated with reference to the following examples. It should also be understood that the following examples are only intended to further illustrate the present disclosure, and cannot be construed as limiting the protection scope of the present disclosure. Those non-essential improvements and modifications made by those skilled in the art according to the principles of the present disclosure all fall into the protection scope of the present disclosure. The specific process parameters used in the following examples are only one example in an appropriate range. Those skilled in the art can make choices in the appropriate range based on the illustration herein. The present disclosure is not limited to the specific data of the following examples.

[0043] The present disclosure will be described in details with reference to the examples and comparative examples. The ingredients of the powder coating material of each example and comparative example are as shown in Table 2 below.

TABLE-US-00002 TABLE 2 No. Comparative Ingredients Example 1 Example 2 Example 3 Example 4 Example 1 Organosilicon modified polyester resin 75 70 75 80 75 (with an acid value of 35-65 mgKOH/g, and an ICI melt viscosity of 3,000-5,000 mPa .Math. s at a temperature of 200° C.) Curing agent Beta-hydroxyalkylamide 7.3 6.7 7.3 8.9 7.3 Blocked isocyanate 1 1 1 1 1 Modified porous calcium silicate 5 10 15 20 0 Filler Barium sulfate — — 10 — — Rutile titanium dioxide 30 28 5 1 10 Silica powder — — — 15 25 Pigment Phthalocyanine blue 2 — 2 — — Ultramarine 5 0.5 — — — Carbon black 0.1 0.2 0.8 0.5 0.3 Iron oxide red — 0.5 0.4 — 0.4 Ciba phthalocyanine green — — — 0.5 — Iron oxide yellow — — — 2 2 Leveling agent Acrylate leveling agent 1.2 1.5 1.2 1.5 1.5 Degassing agent Benzoin 0.5 0.5 0.5 0.7 0.7 Micronized 0.8 — 0.8 — 0.4 polyethylene wax Micronized — 0.8 — 0.8 0.4 polytetrafluoroethylene wax

[0044] The process for preparing the powder coating material for the household appliance coiled material of Examples 1 to 4 and Comparative Example 1 comprised:

[0045] 1) weighing each ingredient according to Table 2, fully mixing in a mixing cylinder and crushing, to obtain a mixed material; and

[0046] 2) melting, mixing, uniformly dispersing and extruding the mixed material in a twin-screw extruder, in which area I had a temperature of 95-105° C. and area II had a temperature of 100-105° C.; then tabletting, cooling and crushing by a tableting machine; grinding by a special grinder and sieving, to obtain powder coating material having a D50 particle size of 25-45 μm.

[0047] The process for preparing the organosilicon modified polyester resin and modified porous calcium silicate of Examples 1 to 4 comprised:

[0048] 1. The polyester resin of the present disclosure was an organosilicon modified carboxyl-terminated polyester resin with an acid value of 35-65 mgKOH/g and a viscosity of 3,000-5,000 (ICI, mPa.Math.s/200° C.), which was mainly obtained by melt poly condensation of the following monomer components, by weight:

[0049] 35-45% of diol,

[0050] 42-52% of aromatic diacid,

[0051] 1.8-11.5% of aliphatic diacid,

[0052] 1.5-3.0% of polyol, and

[0053] 4-6% of organosilicon resin.

[0054] Add the proportion of the diol, polyol and organosilicon resin into a reaction vessel; heat until the material was melted: then sequentially add the proportion of aromatic diacid, an esterification catalyst, and dibutyltin laurate; introduce nitrogen and continue to heat up, until esterified water started to be generated and distilled out at 185° C.; gradually heat up to 240° C. and react for 10-13 h, until 95% of the esterified water was discharged and the acid value reached 20-24 mgKOH/g; then add an acid dissolution reagent to react for 1.5-2.5 h, until the acid value reached 45-75 mgKOH/g; carry out vacuum polycondensation for 2-3 h, until the acid value reached 35-65 mgKOH/g: stop the reaction, resulting in the organosilicon modified polyester resin.

[0055] 2. The process for preparing the modified porous calcium silicate:

[0056] 1) putting porous calcium silicate powder into a high-speed mixer for rotary drying, at a drying temperature of 110-130° C. for 40-120 min, to obtain the porous calcium silicate powder with a moisture content lower than 3%:

[0057] 2) to the obtained porous calcium silicate powder, adding 1% of maleic anhydride, 1% of hydrogen peroxide and 1% of an antioxidant, accounting for the weight of the porous calcium silicate powder; then mixing in the high-speed mixer at 75° C. for 1 hour, to obtain maleic anhydride modified porous calcium silicate;

[0058] 3) to the obtained maleic anhydride modified porous calcium silicate, adding 1% of an amino silane coupling agent (accounting for the weight of the maleic anhydride modified porous calcium silicate); and reacting in the high-speed mixer at 100-120° C. for 20-30 min, to obtain the porous calcium silicate modified by the amino silane coupling agent and maleic anhydride: and

[0059] 4) to the obtained porous calcium silicate modified by the amino silane coupling agent and maleic anhydride, adding 1% of a titanate coupling agent and 1% of an aluminate coupling agent (accounting for the weight of the porous calcium silicate modified by the amino silane coupling agent and the maleic anhydride); mixing in the high-speed mixer at 95-105° C. for 15-20 min; then adding a butyl stearate at 75° C. and mixing for 5-10 minutes, to obtain the modified calcium silicate with good surface wettability.

Performance Tests

[0060] The powder coating materials prepared in Examples 1 to 4 and Comparative Example 1, commercially available coiled building materials were used for the following performance tests:

[0061] 1. Gloss tested according to GB/T 9754;

[0062] 2. Pencil hardness tested according to GB/T 6739-2006:

[0063] 3. Impact performance tested according to GB/T 1732-1993;

[0064] 4. Xenon lamp ageing (1,000 hours) tested according to GB/T 1865-2009:

[0065] 5. Solvent resistance (MEK) tested according to GB/T 12754-2006;

[0066] 6. T-bend performance tested according to GB/T 12754-2006;

[0067] 7. Acid- and alkali resistance test according to GB 9274-1988; and

[0068] 8. Appearance evaluated according to visual observation.

[0069] The results were shown in Table 3.

TABLE-US-00003 TABLE 3 Powder coating material for Comparison Comparative building items Example 1 Example 2 Example 3 Example 4 Example materials Coating 2C1B 2C1B 2C1B 2C1B 2C1B 2C1B process Curing time 30 seconds 30 seconds 30 seconds 30 seconds 30 seconds 30 seconds Line speed 60 m/min 60 m/min 60 m/min 60 m/min 60 m/min 60 m/min Gloss 75 GU 82 GU 85 GU 87 GU 85 GU 40-60 GU Appearance Smooth and Smooth and Smooth and Smooth and Smooth and Smooth and flat flat flat flat flat flat Film 45-80 μm 45-80 μm 45-80 μm 45-80 μm 45-80 μm 45-80 μm thickness Pencil 3 H 3 H 3 H 3 H 2 H 2 H hardness Impact 50 kg .Math. cm 50 kg .Math. cm 50 kg .Math. cm 50 kg .Math. cm 50 kg .Math. cm 50 kg .Math. cm Cracked Xenon lamp aging Gloss Gloss Gloss Gloss Gloss Gloss (1,000 hours) retention ≥82% retention ≥85% retention ≥87% retention ≥90% retention ≥90% retention 82% MEK 188 times 182 times 180 times 175 times 155 times 120 times T-bend 0 T 0 T 0 T 0 T 1 T 1 T-2 T Acid- and No foaming No foaming No foaming No foaming No foaming or Foaming and alkali or peeling off or peeling off or peeling off or peeling off peeling off peeling off resistance within 240 within 240 within 240 within 240 within 240 within 240 hours hours hours hours hours hours