A PROCESS FOR PRODUCING A POLYURETHANE ELASTOMER

Abstract

The present invention relates to a process for producing a polyurethane elastomer, a polyurethane elastomer produced by the process, and the use of the polyurethane elastomer in a glass encapsulation/elastic gasket or the like. The process mainly includes adding a hindered amine light stabilizer to the isocyanate-containing component A. Its reaction with the organotin catalyst in the isocyanate reactive component (i.e. component B), which may cause a loss of the catalytic performance of the catalyst, is avoided. The curing speed of the polyurethane elastomer is increased, thereby the production efficiency is improved and costs are reduced.

Claims

1. A process for producing a polyurethane elastomer, comprising producing the polyurethane elastomer by reacting a reaction system comprising the following components: a component A, comprising: A1) one or more isocyanates; A2) at least one hindered amine light stabilizer in a content of 0.25-8.0 pbw, based on a total weight of the component A; a component B, comprising: B1) an EO-terminated long-chain polyether polyol having a functionality of 3, a hydroxyl value of 17.5-35.5 mgKOH/g, and a weight average molecular weight of 4800-10000 g/mol as determined according to GB/T 21863-2008 in a content of 30-85 pbw, based on a total weight of the component B; B2) optionally an EO-terminated long-chain polyether polyol having a functionality of 2, a hydroxyl value of 14.0-62.0 mgKOH/g, and a weight average molecular weight of 1800-8000 g/mol as determined according to GB/T 21863-2008 in a content of 0-55 pbw, based on a total weight of the component B; B3) a catalyst, comprising B3-1) at least one organotin catalyst.

2. The process as claimed in claim 1, wherein the hindered amine light stabilizer is selected from one, two or more of the group consisting of (2,2,6,6-tetramethyl-4-hydroxypiperidyl) benzoate, bis(2,2,6,6-tetramethyl-4-hydroxypiperidyl) sebacate, nitrilo-tris[(2,2,6,6-tetramethyl-4-hydroxypiperidyl) acetate] and N, N′-bis(2,2,6,6-tetramethylpiperidyl) hexamethylenediamine, tris(1,2,2,6,6-pentamethyl-4-hydroxypiperidyl) phosphite, bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidyl) 2-ethyl-2-(4-hydroxy-3,5-di-tert-butylbenzyl)malonate, and combinations thereof.

3. The process as claimed in claim 1, wherein the B3-1) organotin catalyst is selected from one, two or more of the group consisting of an alkyltin thiolates, an alkyltin mercaptoacetate, a long-chain alkyltin carboxylates, and combinations thereof.

4. The process as claimed in claim 1, wherein the component B further comprises B4) at least one low-molecular-weight polyol/alcohol amine chain extender, which has a content of 2.0-15.0 pbw, based on the total weight of the component B.

5. The process as claimed in claim 1, wherein the component B further comprises B5) a polyether polyol started with ethylene diamine having a hydroxyl value of 330-800 mgKOH/g, a molecular weight of 250-800 g/mol as determined according to GB/T 21863-2008 in a content of 0.5-7.5 pbw, based on the total weight of the component B.

6. The process as claimed in claim 1, wherein the component B further comprises B6) a color paste in a content of 0.1-5.0 pbw, based on the total weight of the component B.

7. The process as claimed in claim 1, wherein a mass ratio of the component A to the component B in the reaction system is 35-80:100.

8. The process as claimed in claim 1, wherein the process is a reaction injection molding process.

Description

EXAMPLES

[0093] The raw materials (including sources), production and test methods of the examples are as follows:

[0094] Raw material 1: Arcol-1362 highly active polyether, Mw=6000, hydroxyl value 26.5 mgKOH/g, Covestro Polymers (China) Co., Ltd.

[0095] Raw material 2: Arcol-3553 highly active polyether polyol, Mw=5000, hydroxyl value 34.5 mgKOH/g, Covestro Polymers (China) Co., Ltd.

[0096] Raw material 3: Arcol-1026 highly active polyether polyol, Mw=4000, f=2, hydroxyl value 28 mgKOH/g, Covestro Polymers (China) Co., Ltd.

[0097] Raw material 4: 1,6-hexanediol, Japan Ube Chemical Co., Ltd.

[0098] Raw material 5: Desmophen4050E, polyether polyol with a diamine as a starter, Mw=350, f=4, hydroxyl value 630 mgKOH/g, Covestro Polymers Co., Ltd.

[0099] Raw material 6: diethyltoluenediamine, Albemarle Chemical Raw material 7: Color paste, BOMEX Chemical Co., Ltd.

[0100] Raw material 8: DC193 Surfactant, Air Product

[0101] Raw Material 9: NIAX UL-6 polyurethane catalyst of organotin type, Momentive

[0102] Raw Material 10: NIAX UL-29 polyurethane catalyst of organotin type, Momentive

[0103] Raw Material 11: NIAX UL-32 polyurethane catalyst of organotin type, Momentive

[0104] Raw Material 12: NIAX UL-38 polyurethane catalyst of organotin type, Momentive

[0105] Raw material 13: ZE-5 polyurethane catalyst of tertiary amine type, EVONIK

[0106] Raw material 14: Tinuvin B75 UV Stabilizer of hindered amine type, BASF (China) Co., Ltd.

[0107] Raw material 15: Desmodur 48IF46 Isocyanate, Covestro Polymers (China) Co., Ltd.

Production of Examples and Comparative Examples (“Comp. Ex.”)

[0108] The isocyanate (plus the corresponding hindered amine light stabilizer in the case of Examples) was placed in a clean vessel, and stirred at 1000 rpm for 3 minutes with a stirrer to be homogeneously mixed, resulting in the component A. The polyether polyol, chain extender, surfactant, catalyst and other additives (plus the corresponding hindered amine light stabilizer in the case of Comparative Examples) were added to a clean vessel and stirred at 1000 rpm for 3 minutes with a stirrer to be homogeneously mixed, resulting in the component B. After mixing the components A and B by mechanical stirring at a temperature of about 40° C., the mixture was poured into a mold controlled to a temperature of about 100° C., and was cured and formed to give a polyurethane elastomer.

Test Method for Performance:

[0109] After the components A and B of the polyurethane reaction system were prepared, they were sealed and placed in an oven at 50° C. for 7 days for a heat aging. After 7 days of heat aging, the components A and B were mixed in proportion and then cured and formed in a heating mold. Whether the mixture of the components A and B can be cured in the heating mold within 1 minute is used as a basis for evaluation of its storage stability.

TABLE-US-00001 Raw Comp. Comp. Comp. Comp. material Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Isocyanate Raw 66.5 64.5 62.5 60.5 66.85 66.85 66.85 66.85 reactive material 1 component B Raw 10 10 10 10 11 11 11 11 material 2 Raw 5 5 5 5 5 5 5 5 material 3 Raw 10 10 10 10 10 10 10 10 material 4 Raw 2 2 2 2 2 2 2 2 material 5 Raw 2 2 2 2 2 2 2 2 material 6 Raw 2 2 2 2 2 2 2 2 material 7 Raw 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 material 8 Raw 0.12 0 0 0 0.12 0 0 0 material 9 Raw 0 0.12 0 0 0 0.12 0 0 material 10 Raw 0 0 0.15 0 0 0 0.15 0 material 11 Raw 0 0 0 0.15 0 0 0 0.15 material 12 Raw 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 material 13 Raw 1.35 3.35 5.35 7.35 0 0 0 0 material 14 The component B is stored in a sealed glass bottle and placed in an oven at 50° C. for 7 × 24 hours to be used later. Isocyanate Raw 0 0 0 0 2.47 3.47 3.47 3.75 component A material 14 Raw 47.0 47.0 47.0 47.0 48.1 48.4 48.1 48.1 material 15 The component A is stored in a sealed glass bottle and placed in an oven at 50° C. for 7 × 24 hours to be used later. Process and Temp. of raw 40 ± 3° C. performance materials stirrer 7 cm turbo mixer, 2500 rpm, stirring time 7 seconds Mold Temp. 95° C. Cured in 1 No No No No Yes Yes Yes Yes minute

[0110] It was found from the above experimental results that in Comparative Examples 1 to 4, both the organotin catalyst and the hindered amine light stabilizer were added to the component B. The catalytic activity of the organotin catalyst was partly or completely lost after a heat aging at 50° C. for 7 days. The polyurethane reaction system could not be cured rapidly, and was not cured even after a long period of time. However, in Examples 1 to 4, the hindered amine light stabilizer was added to the component A. The catalytic activity of the organotin catalyst is not affected after the component B containing the organotin catalyst but without the hindered amine light stabilizer was subjected to a heat aging at 50° C. for 7 days. The polyurethane reaction system could be cured rapidly.

[0111] While the present invention has been described with its preferred embodiments as above, these embodiments are not intended to limit the present invention. It is obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention should be determined by the scope of the claims of the present patent application.