Liquid radiation-curable formulation, in particular for use in stereolithography

• US 5,629,133 A
• Filed: 05/24/1995
• Issued: 05/13/1997
• Est. Priority Date: 08/26/1993
• Status: Expired due to Term

• Current Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Original Assignee: Ciba-Geigy Corporation (Novartis Ag)
• Inventors: Wolf, Jean-Pierre, Schulthess, Adrian, Hunziker, Max, Steinmann, Bettina
• Primary Examiner(s): Berman, Susan W.
• Application Number:
  US08/449,172
• Time in Patent Office: 720 Days
• Field of Search: 522/137, 522/142, 522/148, 522/172, 522/103, 522/182, 522/138, 522/141, 522/143, 430/269, 264/22, 264/236, 264/347
• US Class Current: 430/269
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: G03F 7/0037 Production of three-dimensional images
• CPC Class Codes: G03F 7/0757 Macromolecular compounds containing Si-O, Si-C or Si-N bonds G03F7/0752 takes precedence

Abstract

Liquid radiation-curable formulation, in particular for stereolithography, based on at least one compound that contains radically polymerizable groups, and at least one photoinitiator suitable for the polymerization, which formulation additionally contains a polyoxyalkylene-polysiloxane block copolymer that is selected from copolymers of the chemical formulae ##STR1## wherein: R¹ is a hydrogen atom or a C₁ -C₈ alkyl group;

R² is a methyl or phenyl group;

[T] is a polysiloxane group [PS] terminated as described in the specification in more detail;

[PS] is the group of formula ##STR2## and [Alk] is an alkylene group of 3 to 10 carbon atoms, as well as novel block copolymers of formulae (I) and (II). The cured formulations have, inter alia, superior impact strength.

Claims

1. A process for the preparation of a cured product, which comprises treating a liquid radiation-curable formulation comprising at least one compound that contains free radically polymerisable groups, and at least one photoinitiator suitable for the polymerisation, which formulation additionally comprises a polyoxyalkylene-polysiloxane block copolymer which is selected from copolymers of the chemical formulae ##STR24## in which formulae the individual symbols have the following meanings:

R¹ is a member selected from hydrogen and C₁ -C₈ alkyl;

c is a number from 1 to 8 corresponding to the average number of carbon atoms of an akylene unit in a polyoxyalkylene group (C_c H_2c O)_d ;

d is an integer from 1 to 100;

g is an integer from 1 to 4;

[T] is a group selected from the groups of formulae T1 to T12;

##STR25## [PS] is a polysiloxane of formula ##STR26## R² is a group selected from methyl and phenyl;

b is an integer from 1 to 100;

[Alk] is an alkylene group of 3 to 10 carbon atoms;

[Alk¹ ] is an alkylene group of 1 to 20 carbon atoms;

m is a number from 1 to 8 corresponding to the average number of carbon atoms of an alkylene unit in a polyoxyalkylene group (C_m H_2m O)_n ;

n is an integer from 1 to 50;

[G] is a group of formula ##STR27## X is an atom selected from oxygen and sulfur;

[D] is a divalent hydrocarbon radical containing at least 2 carbon atoms;

e is an integer from 1 to 100, and

f is an integer from 1 to 50

with actinic radiation

with the proviso that when the formulation comprises a polyoxyalkylene-polysiloxane block copolymer of formula (III) then the compounds that contain free radically polymerisable groups are a mixture comprising the following components;

(i) a difunctional monomeric or polymeric acrylate or methacrylate;

(ii) an acrylate or methacrylate having a (meth)acrylate functionality greater than 2;

(iii) an unsaturated monomer of formula ##STR28## wherein R⁵ is a member selected from hydrogen and methyl, and

R⁶ is a radical of formula ##STR29## wherein R⁷ is a radical from the group consisting of tetrahydrofurfuryl, cyclohexyl, 2-phenoxyethyl, benzyl, isobornyl, glycidyl, dicyclopentyl, morpholinoethyl, dimethylaminoethyl and straight-chain and branched C₁ -C₂ alkyl radicals, or if R⁵ is a hydrogen atom, R⁶, in addition to the radicals cited above, can also be a radical selected from the group consisting of pyrrolidon-2-yl, imidazonyl, carbazolyl, anthracenyl, phenyl, C₅ -C₈ cycloalkyl, naphthenyl, 2-norbornyl, pyridyl, N-caprolactamyl, formamidyl, acetamidyl and toluolyl.

2. A process for the production of three-dimensional objects from a formulation comprising at least one compound that contains free radically polymerisable groups, and at least one photoinitiator suitable for the polymerisation, which formulation additionally comprises a polyoxyalkylene-polysiloxane block copolymer which is selected from copolymers of the chemical formulae ##STR30## in which formulae the individual symbols have the following meanings:

R¹ is a member selected from hydrogen and C₁ -C₈ alkyl;

c is a number from 1 to 8 corresponding to the average number of carbon atoms of an akylene unit in a polyoxyalkylene group (C_c H_2c O)_d ;

d is an integer from 1 to 100;

g is an integer from 1 to 4;

[T] is a group selected from the groups of formulae T1 to T12;

##STR31## [PS] is a polysiloxane of formula ##STR32## R² is a group selected from methyl and phenyl;

b is an integer from 1 to 100;

[Alk] is an alkylene group of 3 to 10 carbon atoms;

[Alk¹ ] is an alkylene group of 1 to 20 carbon atoms;

m is a number from 1 to 8 corresponding to the average number of carbon atoms of an alkylene unit in a polyoxyalkylene group (C_m H_2m O)_n ;

n is an integer from 1 to 50;

[G] is a group of formula ##STR33## X is an atom selected from oxygen and sulfur;

[D] is a divalent hydrocarbon radical containing at least 2 carbon atoms;

e is an integer from 1 to 100, and

f is an integer from 1 to 50

by stereolithography, which comprises irradiating a layer of said formulation over the entire surface or in a predetermined pattern with actinic light from an ultraviolet/visible light source, such that within the irradiated areas a layer solidifies in a desired layer thickness, then a new layer of the formulation is formed on the solidified layer, which layer is likewise irradiated over the entire surface or in a predetermined pattern, and such that three-dimensional objects are formed from a plurality of solidified layers which adhere to one another by repeated coating and irradiation.

3. A process according to claim 2, wherein [D] is chosen from alkylene groups of 2 to 8 carbon atoms and divalent hydrocarbon radicals containing not more than 30, preferably not more than 20, carbon atoms, which last mentioned radicals contain at least one six-member-C₁ -C₄ alkyl substituent.

4. A process according to claim 3, wherein

R¹ is a member selected from hydrogen and C₁ -C₄ alkyl

R² is a methyl group;

[Alk] is a --(CH₂)₃ -- group;

[Alk¹ ] is an alkylene group containing 2 to 10, preferably 2 to 4 carbon atoms;

X is an oxygen atom;

[D] is a divalent hydrocarbon radical selected from radicals of the following formulae;

##STR34## c is a number from 2 to 4;

d is an integer from 5 to 50;

b is an integer from 10 to 50;

m is a number from 2 to 4;

n is an integer from 5 to 20;

e is an integer from 1 to 50, and

f is an integer from 1 to 25.

5. A process according to claim 4, wherein

R¹ is a methyl group;

[Alk] and

[Alk¹ ] are each a --(CH₂)₃ -- group;

c is 2;

d if the formulation contains a block copolymer of formula (I) or (II), is an integer from 7 to 25 and, if the formulation contains a block copolymer of formula (III), is an integer from 2 to 20;

g is 1;

m is 2, and

n is an integer from 7 to 20.

6. A process according to claim 2, wherein polyoxyalkylene-polyoxysiloxane block copolymer is selected from copolymers of the chemical formulae (I) and (II) and wherein the compounds that contain free radically polymerisable groups are a mixture comprising the following components:

(i) a difunctional monomeric or polymeric acrylate or methacrylate;

(ii) a tri- or polyfunctional acrylate or methacrylate;

(iii) an unsaturated monomer of formula ##STR35## wherein R⁵ is a member selected from hydrogen and methyl, and

R⁶ is a radical of formula ##STR36## wherein R⁷ is a radical selected from the group consisting of tetrahydrofurfuryl, cyclohexyl, 2-phenoxyethyl, benzyl, isobornyl, glycidyl, dicyclopentyl, morpholinoethyl, dimethylaminoethyl and straight-chain and branched C₁ -C₂ alkyl radicals, or if R⁵ is a hydrogen atom, R⁶, in additional to the radicals cited above, can also be a radical selected from the group consisting of pyrrolidon-2-yl, imidazonyl, carbazolyl, anthacenyl, phenyl, C₅ -C₈ cycloalkyl, naphthenyl, 2-norbornyl, pyridyl, N-caprolactamyl, formamidyl, acetamidyl and toluolyl.

7. A process according to claim 6 comprising as component (i) at least one compound of formula ##STR37## wherein p is 0 or 1,

t is 0 or 1 or, if p is 0, is an integer from 1 to 3,

[Z] is --O--, --S--, --SO₂ -- or C(R¹⁰)(R¹¹)--,

R¹⁰ and

R¹¹ are each independently of the other a radical selected from hydrogen, --CF₃ and methyl,

R¹⁴ if p is 0, is hydrogen or methyl, and, if p is 1, is hydrogen,

R⁸ is p is 0, is hydrogen and if p is 1, is hydroxyl and

R⁹ is hydrogen or methyl,

as component (ii) a triacrylate or trimethacrylate of formula

8. A process according to claim 7, which comprises as component (i) at least two compounds of formula (VI) in which

[Z] in both compounds is a --C(CH₃)₂ -- group, and

p in the formula of one of the two compounds is 0 and in the other is 1,

and component (iii) is selected from 1-vinylpyrrolidone, phenoxyethylacrylate, phenoxyethylmethacrylate and a mixture of at least two of the components.