Method of producing molds and cores suitable for producing fiber composite bodies or cast parts in metal or plastic, mold base material and binder used in the method and molds and cores produced according to the method

1. A method of manufacturing molds and cores suitable for producing fiber composite bodies or cast parts of metal or plastic from a particulate mold base material and a multicomponent binder by 3D printing, the method comprising:

a. pretreating the particulate mold base material with at least one silicon-organic compound having a polar hydrophilic end and a nonpolar hydrophobic end,

wherein

the particulate based material is selected from the group consisting of sand, glass, oxidic, ceramic and glass-ceramic materials, and mixtures thereof,

the polar hydrophilic end of the silicon-organic compound comprises a hydroxyl (—OH), a hydroxylate (—O − ), an amino (—NH 2 ), an ammonium (—NH 4 + ), a carboxyl (—COOH) or a carboxylate group; and

the nonpolar hydrophobic end of the silicon-organic compound comprises at least one alkyl group selected from the group consisting of methyl, ethyl, and propyl;

b. forming a layer of the pretreated particulate mold base material, and

c. applying the binder or at least one component of the binder in liquid form to the layer, wherein b. and c. are repeated; wherein the binder comprises at least one member selected from the group consisting of waterglass, magnesium sulfate, phosphate, and borate.

2. The method as claimed in claim 1 , further comprising at least one of:

the mold base material comprises a particulate material to whose surface the hydrophilic end of the silicon-organic compound is able to attach,

the mold base material comprises at least one water-insoluble, inorganic material,

the at least one water-insoluble inorganic material is selected from the group consisting of sand, glass, oxidic, ceramic and glass-ceramic materials, and mixtures thereof,

the mold base material comprises at least one water-soluble, inorganic material,

the at least one water-soluble inorganic material is a water-soluble salt,

the mold base material comprises at least one water-soluble, organic material,

the at least one water-soluble organic material is a water-soluble polymer or a salt of an organic acid, or a mixture thereof,

the particulate mold base material has a mean particle diameter (d50) of 10 μm to 800 μm, and

the particulate mold base material has a surface area as determined by DIN-ISO 9277 of 50 cm 2 /g to 500 cm 2 /g.

3. The method as claimed in claim 1 , further comprising at least one of:

a polar hydrophilic end of the silicon-organic compound comprises a hydroxyl (—OH), a hydroxylate (—O − ), an amino (—NH 2 ), an ammonium (—NH 4 + ), a carboxyl (—COOH) or a carboxylate group,

a nonpolar hydrophobic end of the silicon-organic compound comprises at least one alkyl group selected from the group consisting of methyl, ethyl, and propyl,

the polar, hydrophilic and the nonpolar, hydrophobic end are bonded to the same Si atom,

the silicon-organic compound used comprises an alkylsilanolate or an alkali metal methylsilanolate,

the nonpolar, hydrophobic end of the silicon-organic compound is bonded to an Si atom and the hydrophilic end is bonded to a C atom,

the Si atom and the C atom are connected via a chain with n atoms, where n is an integer of 1 to 150 and the atoms are selected from C atoms and O atoms and Si atoms, and

the silicon-organic compound comprises a compound with structural formula (I):

where n is an integer of 1 to 100 and m is an integer of 1 to 10 and R is an H atom, and

the silicon-organic compound comprises 3-(polyoxyethylene)propylheptamethyltrisiloxane.

4. The method as claimed in claim 1 , further comprising at least one of:

the binder comprises at least one water-soluble binder component,

the water-soluble binder component comprises at least one member selected from the group consisting of waterglass, magnesium sulfate, phosphate, and borate,

the binder comprises at least one water-insoluble binder component,

the water-insoluble binder component comprises at least one member from the group with particulate silicon dioxide and calcium carbonate,

the binder comprises water or an aqueous solution or an aqueous alkaline solution, and

the binder comprises an additive that influences its processing properties.

5. The method as claimed in claim 1 , further comprising at least one of:

at least one binder component is present as a stationary binder component in the layer of the mold base material,

the stationary binder component is the water-insoluble binder component or one of the water-insoluble components,

the stationary binder component is the water-soluble binder component or one of the water-soluble components,

the mold base material has been pretreated with the stationary binder component, and

the at least one binder component applied in liquid form to the layer comprises at least one member selected from the group consisting of water, an aqueous hydroxide solution, a waterglass solution, an aqueous solution of magnesium sulfate, an aqueous phosphate solution, and an aqueous borate solution.

6. The method as claimed in claim 1 , further comprising at least one of:

after application of the binder or the at least one component of the binder to the layer, the binder is cured,

the curing takes place by microwave radiation,

the curing takes place chemically, and

the curing takes place thermally.

7. A method of manufacturing molds and cores suitable for producing fiber composite bodies or cast parts of metal or plastic from a particulate mold base material and a multicomponent binder by 3D printing, the method comprising:

a. pretreating the particulate mold base material with at least one silicon-organic compound having a polar hydrophilic end and a nonpolar hydrophobic end,

b. forming a layer of the pretreated particulate mold base material, and

C. applying the binder or at least one component of the binder in liquid form to the layer,

wherein b. and c. are repeated;

further comprising:

for the pretreating step, the silicon-organic compound is added to the particulate mold base material in an amount such that it is present in the pretreated mold base material in a weight fraction of at least 0.01 wt % and of at most 0.2 wt % based on a dry weight of the pretreated mold base material.

8. A method of manufacturing molds and cores suitable for producing fiber composite bodies or cast parts of metal or plastic from a particulate mold base material and a multicomponent binder by 3D printing, the method comprising:

a. pretreating the particulate mold base material with at least one silicon-organic compound having a polar hydrophilic end and a nonpolar hydrophobic end,

b. forming a layer of the pretreated particulate mold base material, and

c. applying the binder or at least one component of the binder in liquid form to the layer, wherein b. and c. are repeated;

further comprising at least one of:

at least one binder component is present as a stationary binder component in the layer of the mold base material,

the stationary binder component is the water-insoluble binder component or one of the water-insoluble components,

the stationary binder component is the water-soluble binder component or one of the water-soluble components,

the mold base material has been pretreated with the stationary binder component, and

the at least one binder component applied in liquid form to the layer comprises at least one member selected from the group consisting of water, an aqueous hydroxide solution, a waterglass solution, an aqueous solution of magnesium sulfate, an aqueous phosphate solution, and an aqueous borate solution;

wherein:

the mold base material is a sand treated with an alkylsilanolate or potassium methylsiliconate,

optionally for a casting application, silicon dioxide is present as a stationary binder component in the layer of the mold base material,

waterglass solution is applied as a liquid binder component to the layer, and

a curing takes place by microwave radiation.

9. A method of manufacturing molds and cores suitable for producing fiber composite bodies or cast parts of metal or plastic from a particulate mold base material and a multicomponent binder by 3D printing, the method comprising:

a. pretreating the particulate mold base material with at least one silicon-organic compound having a polar hydrophilic end and a nonpolar hydrophobic end,

b. forming a layer of the pretreated particulate mold base material, and

c. applying the binder or at least one component of the binder in liquid form to the layer,

wherein b. and c. are repeated;

wherein the particulate mold base material further comprises at least one of:

a polar hydrophilic end of the silicon-organic compound comprises a hydroxyl (—OH), a hydroxylate (—O − ), an amino (—NH 2 ), an ammonium (—NH 4 + ), a carboxyl (—COOH) or a carboxylate group,

a nonpolar hydrophobic end of the silicon-organic compound comprises at least one alkyl group selected from the group consisting of methyl, ethyl, and propyl,

the polar, hydrophilic and the nonpolar, hydrophobic end are bonded to the same Si atom,

the silicon-organic compound used comprises an alkylsilanolate or an alkali metal methylsilanolate,

the nonpolar, hydrophobic end of the silicon-organic compound is bonded to an Si atom and the hydrophilic end is bonded to a C atom,

the Si atom and the C atom are connected via a chain with n atoms, where n is an integer of 1 to 150 and the atoms are selected from C atoms and O atoms and Si atoms, and

the silicon-organic compound comprises a compound with structural formula (I):

where n is an integer of 1 to 100 and m is an integer of 1 to 10 and R is an H atom, and the silicon-organic compound comprises 3-(polyoxyethylene)propylheptamethyltrisiloxane;

wherein:

the mold base material is a sand treated with the silicon-organic compound according to formula (I),

optionally the silicon dioxide is present as a stationary binder component in the layer of the mold base material,

an ester curing agent is present as a curing agent as a stationary binder component in the layer of the mold base material, and

the waterglass solution is applied as a liquid binder component to the layer.

10. A method of manufacturing molds and cores suitable for producing fiber composite bodies or cast parts of metal or plastic from a particulate mold base material and a multicomponent binder by 3D printing, the method comprising:

a. pretreating the particulate mold base material with at least one silicon-organic compound having a polar hydrophilic end and a nonpolar hydrophobic end,

b. forming a layer of the pretreated particulate mold base material, and

c. applying the binder or at least one component of the binder in liquid form to the layer,

wherein b. and c. are repeated;

wherein the particulate mold base material further comprises at least one of:

a polar hydrophilic end of the silicon-organic compound comprises a hydroxyl (—OH), a hydroxylate (—O − ), an amino (—NH 2 ), an ammonium (—NH 4 + ), a carboxyl (—COOH) or a carboxylate group,

a nonpolar hydrophobic end of the silicon-organic compound comprises at least one alkyl group selected from the group consisting of methyl, ethyl, and propyl,

the polar, hydrophilic and the nonpolar, hydrophobic end are bonded to the same Si atom,

the silicon-organic compound used comprises an alkylsilanolate or an alkali metal methylsilanolate,

the nonpolar, hydrophobic end of the silicon-organic compound is bonded to an Si atom and the hydrophilic end is bonded to a C atom,

the Si atom and the C atom are connected via a chain with n atoms, where n is an integer of 1 to 150 and the atoms are selected from C atoms and O atoms and Si atoms, and

the silicon-organic compound comprises a compound with structural formula (I):

where n is an integer of 1 to 100 and m is an integer of 1 to 10 and R is an H atom, and the silicon-organic compound comprises 3-(polyoxyethylene)propylheptamethyltrisiloxane;

wherein:

the mold base material is a sand treated with the silicon-organic compound according to formula (I),

optionally the silicon dioxide is present as a stationary binder component in the layer of the mold base material,

the waterglass is present as a stationary component of the binder in the layer, and

an ester curing agent is applied as liquid binder component to the layer.