Polyisocyanate polyaddition products, a process for preparation thereof and use thereof

1. A polyisocyanate polyaddition product with good mechanical properties obtained by reacting

a) a polyisocyanate and

b) a NCO-reactive compound selected from the group consisting of b1) long-chain polyester polyols with an OH number of from 27 to 112 mg KOH/g and a functionality of from 1.9 to 2.3, b2) short-chain hydroxyl compounds with an OH number of from 300 to 1810 mg KOH/g and a functionality of from 1.9 to 2.3, and mixtures thereof,

in the presence of components consisting of

c) a latent catalyst

d) optionally a tin catalyst,

e) optionally a filler and/or fiber material,

f) optionally an assistant and/or an additive,

g) optionally a blowing agent, and

h) at least one water scavenger,

wherein the latent catalyst c) consists of a monocarboxylic acid-blocked amidine in an amount of from 20 to 400 ppm, based on component b1), wherein the molar ratio of amidine to carboxylic acid is between 1:3 and 1:0.5,

wherein the casting time of the polyisocyanate polyaddition product is from 2 to 10 minutes and the hardness is from 60 to 96 Shore A.

2. The polyisocyanate polyaddition product of claim 1 , wherein the polyisocyanate a) is a NCO prepolymer formed from diphenylmethane diisocyanate (MDI) and/or carbodiimidized/uretoniminized diphenylmethane diisocyanate and/or allophanatized MDI.

3. The polyisocyanate polyaddition product of claim 1 , wherein the polyisocyanate a) is a NCO prepolymer based on polyester polyol.

4. A process for preparing the polyisocyanate polyaddition product comprising reacting

a) a polyisocyanate with

b) a NCO-reactive compound selected from the group consisting of b1) long-chain polyester polyols with an OH number of from 27 to 112 mg KOH/g and a functionality of from 1.9 to 2.3, b2) short-chain hydroxyl compounds with an OH number of from 300 to 1810 mg KOH/g and a functionality of from 1.9 to 2.3, and mixtures thereof,

in the presence of components consisting of

c) a latent catalyst

d) optionally a tin catalyst,

e) optionally a filler and/or fiber material,

f) optionally an assistant and/or an additive,

g) optionally a blowing agent, and

h) at least one water scavenger,

wherein the latent catalyst c) comprises a monocarboxylic acid-blocked amidine in an amount of from 20 to 400 ppm, based on component b1), wherein the molar ratio of amidine to carboxylic acid is between 1:3 and 1:0.5.

5. The process of claim 4 , wherein the latent catalyst c) is added via the NCO-reactive compound b) and the catalyst d) is added separately.

6. The process of claim 4 , wherein the latent catalyst c) and the catalyst d) are added via the NCO-reactive compound b).

7. The process of claim 4 , wherein the latent catalyst c) and a portion of the amount of the catalyst d) are added via the NCO-reactive compound b) and the rest of the amount of the catalyst d) is added separately.

8. An article comprising the polyisocyanate polyaddition product of claim 1 , wherein the article is a screen, a pipeline pig, a roll, a wheel, a roller, a stripper, a plate, a cyclone, a conveyor belt, a coating bar, a coupling, a seal, a buoy or a pump.