CN1401680A - Hard polyurethane casting material - Google Patents

Abstract

The invention relates to a rigid polyurethane pouring material, which includes three components A, R and F, wherein component A is composed of 65-90% polyisocyanate with a functionality of 2-2.7 and a molecular weight of 400- 10000 semi-prepolymers synthesized by 10-35% polyether polyols, the content of free isocyanate groups in the semi-prepolymers is between 18-35%; the R component includes 10-40% chain extenders, 30 ～60% polyether polyol, 1～5% additives; F component is reinforcing fiber. The material has wear resistance, corrosion resistance, shock resistance, impact resistance, dimensional stability, etc. It is suitable for the production of structural parts and replaces some metal materials.

Description

A hard polyurethane casting material

technical field

The invention relates to a polyurethane polymer material, in particular to a rigid polyurethane pouring material, which is suitable for making structural parts and replaces some metal materials.

Background technique

Commonly used polymer composite materials include epoxy resin, unsaturated polyester resin, phenolic resin, polyvinyl resin, etc., but the above materials all have different shortcomings, such as poor toughness of epoxy resin, and thermal shrinkage of unsaturated polyester resin. High rate, poor curing behavior of phenolic resin and polyvinyl resin, poor wear resistance, etc. As a new type of polymer material, polyurethane has high mechanical strength, excellent fatigue strength, thermal shock resistance, wear resistance, tear resistance, etc., and is very suitable for the production of structural parts.

In US Patent No. 5,234,975, fiber-reinforced rigid polyurethane pouring material is reported, but the disadvantage of the invention is that it needs to be poured at about 40-60°C, and the castable period is about 2-3 minutes, which is not conducive to manual operation. In US Pat. No. 5,234,975, it is reported that fiber-reinforced polyurethane material is used as the outer layer of football, and the hardness is at Shore A40-80, but the hardness of this material is too low to be used as a structural material.

The object of the present invention is to provide a hard polyurethane casting composite material, which has low viscosity, long pouring period, can be cured at room temperature and cast at normal pressure, and the cured product has high mechanical strength, excellent fatigue strength, heat resistance Impact, wear resistance, tear resistance, etc., can be processed by turning, milling, planing, grinding, etc., suitable for making various mechanical parts as a structural material.

Contents of the invention

The rigid polyurethane casting material of the present invention comprises three components of A, R and F;

Among them, component A is synthesized by 65-90% (based on the total weight of component A) of polyisocyanate with a functionality of 2-2.7 and 10-35% of polyether polyol with a molecular weight of 400-10000 A semi-prepolymer, the content of free isocyanate groups in the semi-prepolymer is between 18% and 35%;

The R component (based on the total weight of the R component) includes 10-40% chain extender, 30-60% polyether polyol, and 1-5% auxiliary agent;

Component F is a reinforcing fiber.

The preparation method of component A is as follows: add accurately measured polyisocyanate into the reaction kettle, stir at a constant speed, heat to 50-80°C, add dropwise accurately measured polyol compound into the kettle, keep warm while stirring, and the dropwise addition is completed Then gradually raise the temperature to 85±2°C and keep it warm for 3 hours. After sampling and measuring the NCO content reaches the theoretical value, cool and discharge the material to obtain a semi-prepolymer with excess isocyanate. Generally, the free isocyanate group content in the semi-prepolymer is between 18 and 35%.

The free isocyanate group content in the above-mentioned semi-prepolymer is preferably between 25% and 35%.

The preparation method of the R component is: add accurately measured polyether polyols, chain extenders, and additives into the reaction kettle, mix well, and heat up to 100°C for about 2 hours of vacuum dehydration. 0.05% can be discharged to get the R component.

The polyisocyanate in the semi-prepolymer is preferably one or more of the following: carbodiimide-uretonimine modified 4,4'-diphenylmethane diisocyanate (LMDI), polymethyl polyphenyl poly Isocyanate (PAPI), 4,4'-diphenylmethane diisocyanate (MDI), 2,4'-diphenylmethane diisocyanate (2,4-MDI), toluene diisocyanate (TDI), etc.

The polyether polyol in the above-mentioned semi-prepolymer and the polyether polyol in the R component are usually propylene oxide or ethylene oxide polyether, and its functionality is between 2 and 4. Its molecular weight is between 400 and 10,000, preferably between 500 and 5,000, preferably one or more of the following: polyethylene glycol ether, polypropylene glycol ether, polyglycerol ether, polypentaerythritol ether, polytetrahydrofuran ether glycol And the copolymers with the above structures also include polyether polyols with low unsaturation, such as Acclaim3201 of Acro Company.

The chain extenders in the R component include amine chain extenders and alcohol chain extenders.

Among them, the functionality of the amine chain extender is most typically between 2 and 3. Preferred are diethyltoluenediamine (DETDA), dimethylthiotoluenediamine (DADMT), N,N'-di-sec-butylmethylenediphenyldiamine, 4,4'-diaminodiphenyl Methane (MDA), 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA), aliphatic polyamines.

Alcohol chain extenders are preferably 1,4-butanediol (BDO), 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, trimethylolpropane (TMP), Glycerol, triethanolamine, etc.

The additives in the R component include: catalysts, antioxidants, ultraviolet light absorbers, and anti-precipitation agents. The catalysts include organic metals, such as organic tin, organic mercury, organic bismuth; organic amines such as: triethylenediamine, triethylamine, the best selection of organic metals, such as T-12, T-9, etc.;

Antioxidants such as IRGANOX 1010 and 1076 from CIBA GEIGY, YOSHINOX BHT, BB, GSY-930 from YOSHITOMSEIYAKU; UV absorbers such as TINUVIN P, 327, 328 from CIBA GEIGY; anti-sedimentation agents such as BYK- 203, BYK-401.

Component F is composed of chopped or hammer-milled fibers, which mainly play a reinforcing role, including glass fibers, carbon fibers, graphite fibers, nylon fibers, etc. The length of the fibers is between 1.5 and 5 mm, and the diameter is between 10 and 40 microns. . It is best to be treated with a coupling agent, such as A-187, A-186, and A-1230 from Witco. The amount of fiber added is controlled so that the mixed solution has better fluidity, and the mixture has sufficient viscosity to ensure the suspension of the fibers, thereby ensuring the uniformity of the cured product. The oil absorption of different fibers is different, generally the amount added is 20-60% (weight) of the total amount of the mixture of A and R.

The synthesis method of the rigid polyurethane pouring material of the present invention is as follows: after mixing A and R components uniformly at a weight ratio of 1:1, adding reinforcing fibers, mixing uniformly again, and pouring into a mould. Curing and demoulding in a short period of time to form a rigid structural material with high hardness and strong toughness.

The rigid structural part exhibits excellent properties, such as wear resistance, corrosion resistance, shock resistance, impact resistance, dimensional stability, etc., and can be machined by turning, milling, planing, grinding, etc., and is suitable as a structural material Make various mechanical parts such as gears, wind turbine blades, bases, etc.

Detailed ways

Several typical examples are given below, but the present invention is not limited to the following examples. Example 1:

Preparation of component A: Add 600g polymethyl polyphenyl polyisocyanate (PAPI) and 200g carbodiimide-uretonimine modified 4,4'-diphenylmethane diisocyanate (LMDI) to the reaction In the kettle, stir at a constant speed, heat to 50-80°C, add 200g of polypropylene oxide diol (molecular weight: 1000, functionality: 2) dropwise into the kettle, keep warm while stirring, and gradually raise the temperature to 85 ±2°C and keep it warm for 3 hours, take a sample to test that the NCO content reaches the theoretical value, then cool and discharge the material to obtain a semi-prepolymer with excess isocyanate. Tested by di-n-butylamine method, the free isocyanate content of component A was 23.5%.

Preparation of R component: 174g 330N (polyether polyol, molecular weight 4950, functionality 3, Shandong Dongda Chemical Group), 500g 210 (polyether polyol, molecular weight 1000, functionality 2, Shandong Dong Big Chemical Industry Group), 100g trimethylolpropane TMP and 200g dimethylthiotoluenediamine (Albemarle, the United States), 10g antioxidant (CIBA GEIGY, Irganox1076) and 10g ultraviolet light absorber (CIBA GEIGY, Tinuvin 328), 1g of catalyst (American Gas Company, T-12), 5g of anti-settling agent (BYK Company, BYK-203) were added to the reactor and mixed well, heated to 100°C and dehydrated for 2 hours, and the moisture content of the sample test was 0.03%, the R component is obtained immediately after discharge.

Mix 100g of A and 100g of R thoroughly, add 80g of glass fiber (length 3mm, diameter 20 microns) and stir evenly again, pour the above materials into the mold, and the mold can be released after 40 minutes. After the cured product was placed at room temperature for a week, the performance test was performed, and the results are as follows:

Viscosity (25°C, cps) A 250

R 800

A, R, F mixture 500

Pouring time/minute 15

     Demolding Time/Min                                                    

                                                                                                       

Shrinkage (%) 0.0022

Elongation (%) 6%

                                                                                              

      Flexural strength/psi   8500 Example 2:

Preparation of component A: Add 275g of polymethyl polyphenyl polyisocyanate (PAPI) and 600g of 4,4'-diphenylmethane diisocyanate (MDI) into the reaction kettle, stir at a constant speed, and heat to 50-80°C. Add 125g of polypropylene oxide diol (molecular weight is 2000, functionality is 2) dropwise in kettle, keep warm while stirring, gradually heat up to 85±2°C after dropwise addition and keep warm for 3 hours, take samples to measure NCO content reaches After the theoretical value, the material is cooled and discharged to obtain a semi-prepolymer with excess isocyanate. The free isocyanate content of component A was 29% when tested by the di-n-butylamine method.

Preparation of R component: 224g 330N (polyether polyol, molecular weight 4950, functionality 3, Shandong Dongda Chemical Group), 500g 210 (polyether polyol, molecular weight 1000, functionality 2, Shandong Dong Big Chemical Industry Group), 100g trimethylolpropane TMP and 150g1,4 butanediol (BDO), 10g antioxidant (CIBA GEIGY, Irganox 1076) and 10g ultraviolet absorber (CIBA GEIGY, Tinuvin 328), 1g catalyst (American Gas Company, T-12), 5g of anti-settling agent (BYK Company, BYK-203) were added to the reactor and mixed well, heated to 100°C and dehydrated for 2 hours, the moisture content of the sampling test was 0.03%, and the material was discharged That is the R component.

Fully mix 100g A and 100g R, add 100g carbon fiber (length 4mm, diameter 20 microns) and stir again, pour the above materials into the mold, and the mold can be released after 40 minutes. The performance test was performed after the cured product was placed at room temperature for a week, and the results are as follows:

Viscosity (25℃, cps) A 200

R 850

A, R, F mixed

Compound 500

Pouring time/minute 10

     Demolding Time/Min                                                             

                                                                                                                                          

Shrinkage (%) 0.0025

Elongation (%) 6%

                                                                                                              ,

                                                                       

Example 3:

Preparation of component A: Add 950g of 2,4'-diphenylmethane diisocyanate (2,4'-MDI) into the reaction kettle, stir at a constant speed, heat to 50-80°C, and drop 50g of polycyclic Oxypropane diol (molecular weight is 2000, functionality is 2), keep warm while stirring, gradually heat up to 85±2°C after dropwise addition and keep warm for 3 hours, take samples to measure the NCO content to reach the theoretical value, then cool and discharge, That is, a semi-prepolymer with excess isocyanate is obtained. Tested by the di-n-butylamine method, the free isocyanate content of component A was 32%.

Preparation of R component: 224g 330N (polyether polyol, molecular weight 4950, functionality 3, Shandong Dongda Chemical Group), 400g 210 (polyether polyol, molecular weight 1000, functionality 2, Shandong Dong Big Chemical Industry Group), 50g 403 (polyether polyol, molecular weight is 300, functionality is 4, Nanjing Jinling Petrochemical), 150g trimethylolpropane TMP and 150g 1,4 butanediol (BDO), 10g antioxidant (CIBA GEIGY, Irganox 1076) and 10g UV absorber (CIBA GEIGY, Tinuvin 328), 1g catalyst (American Gas Company, T-12), 5g anti-settling agent (BYK Company, BYK-203) were added to the reactor Mix thoroughly and evenly, heat to 100°C and dehydrate for 2 hours, take a sample to test the moisture content is 0.03%, and get the R component after discharging.

Mix 100g A and 100g R thoroughly, add 100g nylon fiber (3mm in length, 30 microns in diameter) and stir evenly again, pour the above materials into the mold, and the mold can be released after 40 minutes. After the cured product was placed at room temperature for a week, the performance test was performed, and the results are as follows:

A 100 Viscosity A 100

(25℃, cps)

R 810

A, R, F mixed

Compound 700

          Pouring time/min                                          

Demoulding time/min 50

                                                                                                  

Shrinkage rate 0.002

Elongation (%) 6%

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Claims (10)

1. A rigid polyurethane casting material, characterized in that it comprises A, R, and F three components; Among them, component A is synthesized by 65-90% (based on the total weight of component A) of polyisocyanate with a functionality of 2-2.7 and 10-35% of polyether polyol with a molecular weight of 400-10000 A semi-prepolymer, the content of free isocyanate groups in the semi-prepolymer is between 18% and 35%; The R component (based on the total weight of the R component) includes 10-40% chain extender, 30-60% polyether polyol, and 1-5% auxiliary agent; Component F is a reinforcing fiber. 2. The rigid polyurethane casting material according to claim 1, characterized in that, the preparation method of the A component is: adding the accurately metered polyisocyanate into the reaction kettle, stirring at a constant speed, heating to 50-80°C, Add dropwise accurately measured polyol compound in the medium, keep it warm while stirring, gradually raise the temperature to 85±2°C and keep it warm for 3 hours after the dropwise addition is completed, take a sample to measure the NCO content to reach the theoretical value, then cool and discharge the material to obtain the half of the excess isocyanate prepolymer. 3. The rigid polyurethane casting material according to claim 1, characterized in that, the preparation method of the R component is: adding accurately metered polyether polyols, chain extenders, and auxiliary agents into the reactor and fully mixing them uniformly , and heated up to 100°C for about 2 hours of vacuum dehydration, and when the water content is lower than 0.05%, the material can be discharged to obtain the R component. 4. according to the rigid polyurethane pouring material of claim 1, it is characterized in that, polyisocyanate is preferably following one or more in the described semi-prepolymer: carbodiimide-uretonimine modified 4,4 '-Diphenylmethane diisocyanate (LMDI), polymethyl polyphenyl polyisocyanate (PAPI), 4,4'-diphenylmethane diisocyanate (MDI), 2,4'-diphenylmethane diisocyanate Isocyanate (2,4-MDI), toluene diisocyanate (TDI), etc. 5. according to the rigid polyurethane pouring material of claim 1, it is characterized in that, the polyether polyol in the above-mentioned semi-prepolymer and the polyether polyol in the R component usually adopt propylene oxide or oxyethylene Polyether, its functionality is between 2 and 4, and its molecular weight is between 400 and 10,000. 6. according to the rigid polyurethane pouring material of claim 5, it is characterized in that, described polyether polyol is preferably following one or more: polyethylene glycol ether, polypropylene glycol ether, polyglycerol ether, polypentaerythritol ether , polytetrahydrofuran ether diol and the copolymer of the above structure, low unsaturation polyether polyol. 7. The rigid polyurethane casting material according to claim 1, characterized in that, the chain extender in the R component includes an amine chain extender and an alcohol chain extender. 8. The rigid polyurethane casting material according to claim 7, characterized in that the functionality of the amine chain extender is most typically between 2 and 3. Preferred are diethyltoluenediamine (DETDA), dimethylthiotoluenediamine (DADMT), N,N'-di-sec-butylmethylenediphenyldiamine, 4,4'-diaminodiphenyl Methane (MDA), 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA), aliphatic polyamines. 9. The rigid polyurethane castable material according to claim 1, characterized in that, the length of the reinforced fiber of the F component is between 1.5-5 mm, and the diameter is between 10-40 microns, including: glass fiber, carbon fiber , graphite fiber, nylon fiber, its add-on is 20～60% (weight) of A and R mixture total amount. 10. The synthetic method of rigid polyurethane pouring material of the present invention is: after A, R two components are mixed uniformly by weight ratio 1:1, and add reinforcing fiber, mix uniformly again, cast in the mould, solidify at room temperature, take off mold.