DE2252610A1 - SUSPENSION POLYMERIZATION PROCESS FOR THE PRODUCTION OF POLYURETHANE UREA MASSES - Google Patents

Description

225261Q

ratentänwäut.e

23 688

American Cyanamid Company "Wayne, New Jersey, V.St.A.

Suspension polymerization process for manufacture of polyurethane-urea compounds

The invention relates to a suspension polymerization system for the production of polyurethane-urea masses in the form of uniform and stable pearl-like Particle.

It is well known that diisocyanate with organic dihydroxy compounds, especially with hydroxy end groups containing polyethers, polyesters and polyacetals, in the presence of water to tough rubbery Products react. It is also known to combine such polyesters, polyethers and polyacetals with diisocyanates implement and the pre-condensate thus generated in a rolling mill with the addition of limited and carefully measured To treat amounts of water during the rolling process. Finally, polyurethane-urea elastomers are also known in the form of stable emulsions (latices), from which a processable elastomer is produced

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Precipitation of the polymer is obtained.

Various disadvantages occur in the production of polyurethane-urea compositions by these methods. First, the procedures are inherently time consuming and cumbersome and sometimes difficult. Second, wise the products obtained have various undesirable properties. So leave the masses produced usually Missing uniformity and stability. Poor handling properties are another disadvantage. The products are usually tough, rubber-like masses of sticky particles which often tend to agglomerate. In the case of latices, the recovery of the polymer by precipitation is cumbersome, complex and time-consuming, since the obtained polymer mass often requires multiple washing and drying on a rubber mill.

A process has now been found for producing uniform, stable polyurethane-urea masses in which a Prepolymer with isocyanate end groups, which is obtained by reacting an aliphatic polyol with a hydroxyl end group from the Group of polyalkylene ether glycols, polyesters, polyacetals or their mixtures with a stoichiometric one An excess of an organic diisocyanate is obtained, mixed with an inert suspending agent and water and the resulting mixture is stirred at high speed until discrete particles are formed. The stirring speed must be sufficient to form the system as a suspension and to keep it in suspension. The procedure provides a linear stable non-tacky polyurethane-urea product that emerges from the reaction medium can be easily recovered by filtration, washing and drying.

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-3- 225261Q.

The product that is in the form of free-flowing particles is then immediately available for further use.

In general, any organic compound can have a Molecular weight greater than about 500, containing at least 2 active hydrogen atoms, with a stoichiometric Excess of an organic diisocyanate to be reacted to a prepolymer, which with water according to the invention Process can be extended chain. Active hydrogen-containing compounds are, however, for the purposes of the invention as polyester, polyether or Polyacetals with hydroxyl end groups or mixtures thereof are defined, albeit other substances, for example polyester amides , can also be used.

Polyalkylene ether glycols have the formula

H (OP) _n OH,

where R is an alkylene radical and η is a whole number with sufficient high value means that the polymer obtained has a molecular weight of at least 500. Molecular weights up to about 5000 are preferred, although higher Molecular weights can be applied. To such polyalkylene ether glycols include, for example, poly-1,2-propylene ether glycol, Poly-1,3-propylene ether glycol, polytetramethylene ether glycol, Poly-1,2-diethylethylene ether glycol and polydecamethylene ether glycol. The preferred polyalkylene ether glycols are polytetramethylene ether glycol and Poly-1,2-propylene ether glycol,

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Suitable polyesters are those produced by condensation a stoichiometric excess of a diol, for example Ethylene glycol, 1,2-propylene glycol, diethylene glycol, Triethylene glycol, 1,4-butanediol, pentainethylene glycol, Hexamethylene glycol and the like, with an aliphatic dicarboxylic acid, for example malonic acid, glutaric acid, succinic acid, Adipic acid, pimelic acid and the like. Preferred polyesters are polyethylene adipate and polybutylene adipate having a molecular weight of from about 500 to about 5000, and especially from about 10,000 to 3000.

Advantageous polyacetals are those obtained by condensation of an aliphatic diol having about 4 to 10 carbon atoms be made with formaldehyde. You have the structure

HO - / - (CH ₂ ) _n -O-CH ₂ -O_ / _m - (CII ₂ ) _n "0H,

where m is the degree of polymerization and η is the number of carbon atoms denoted in the Dlol. You are in from Schonfeld J. Poly. May be. 59, 87 (% 962) has been described. Polyacetals for purposes of the invention have molecular weights from about 500 to 5000.

In addition to the high molecular weight polyols, smaller amounts of low molecular weight diols, which have a codifying effect, can also be used Have an effect on the properties of the end product, including ethylenically unsaturated diols, which represent the introduction of Vulkiuni sat Ions can serve in the polymer mass.

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To produce the polyurethane-urea masses, various organic isocyanates can be used. Representative compounds are, for example, 2,4-toluene diisocyanate, 2,6-tolylene diisocyanate and mixtures of isomers thereof, m-phenylene diisocyanate, p-xylylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, Methylene bis (4-phenyl isocyanate), 1,5-naphthylene diisocyanate and the like, as well as the aliphatic Diisocyanates, for example tetramethylene diisocyanate and HeKamethylene diisocyanate. Preferred diisocyanates are methylene bis (4-phenyl isocyanate) and 2,4-toluene diisocyanate / which are referred to below as MDI or 2,4-TDI.

In some cases, a modification of the chain length can be useful. This can be done by using smaller ones Amounts of organic monoisocyanates can be achieved in the preparation of the polyurethane prepolymer. Also aliphatic and aromatic monoamines, which are added in smaller amounts during the chain extension reaction, can be added to can be used for this purpose.

The molar ratio of organic diisocyanate to polyol used in making the polymers of the invention is in the range of about 1.2: 1 to about 5: 1, and preferably about 1.4: 1 to about 2 * 1. As from the As can be seen in the examples, the product is usually a viscous liquid that is used directly in the process can be. In order to reduce the viscosity, it can be useful in some cases to use an inert organic Add solvents, for example tetrahydrofuran, acetonitrile, toluene, xylene or the like. Prepolymers, in their preparation the higher ratios of diisocyanate to polyol, i.e. higher than about T, 9: 1, were used contain enough unreacted monomer

■ / '225261Q

Diisocyanate to produce high concentrations of high melting point polyureas in the extended with water To yield polymers. Such polymers are still soluble in some solvents and can be used for coatings, but can because of their high melt flow temperatures for the production of moldings by extrusion or Injection molding may not be suitable. In such cases it is often desirable to have high proportions of organic diisocyanate to apply polyol and the excess monomeric diisocyanate by suitable measures, for example extraction or to remove distillation prior to chain extension with water. Prepolymers produced in this way are in the U.S. Patent 3,503,933.

The chain extension reaction with water to produce the desired bead-like particles is dependent on the formation of a stable suspension of the polymer particles during the reaction. Suitable inert suspending agents, which are defined as substances with the aid of which a system of fine particles can be prevented from settling, include, for example, inorganic substances such as bentonite (sodium montmorillonite), tricalcium phosphate and the like, or organic substances such as polyvinyl alcohol, hydroxyethyl cellulose, water-soluble gums and the like as well as mixtures of these suspending agents. The preferred suspending agents are bentonite, tricalcium phosphate and polyvinyl alcohol. The suspending agent is used in sufficient amount to prevent agglomeration of the polymer beads. Depending on the type used, this usually requires from 0.1 to about 5 % of the suspending agent, based on the weight of the propolymers subjected to the reaction.

J U 9 8 I 9 / Γ 0 2 2

Surprisingly, is the one used in the implementation The amount of water is not critical and, within wide limits, its concentration has no adverse effect on the molecular weight of the polymer, although it is the only chain extender. This result is very unexpected. In general, at least an amount of water should be present which results in a stable suspension which can be easily stirred when the entire polymer is added is. .

The temperature of the chain extension reaction is not critical and ranges from normal room temperatures to about 80 ° C., depending on the particular system. Temperatures in the range from about 30 to about 60 ^° C. are usually suitable.

A catalytic converter is generally used for acceleration the chain extension reaction is not required, often however, a catalyst is useful in order to complete the reaction in the shortest possible time. To suitable catalysts for this purpose include, for example, triethylamine and 13, N * -dimethylpiperazine.

In order to improve the suspending effect of the inorganic suspending agent (by deflocculation) / it is sometimes useful to however, it is not necessary to use the suspension system with a to add a small amount of surfactant. These funds are used in amounts that are not are sufficient 'for them to act as suspending agents / ... a a suitable agent is sodium lauryl sulfate or a linear one Sodium alkyl sulfonate.

When the suspension system is prepared, the prepolymer becomes with isocyanate end groups either as such or with a

309819 / 1.0: 2? -

- Sf -

Diluted solvent is added to the suspension system with rapid stirring at a moderate rate. The two Components can also be combined in a mixing head. The implementation is quick and leads to a Suspension of hard non-agglomerating particles of polyurethane-urea. Once this stage is reached, which is usually the case after several minutes, the reaction mixture can be transferred to a suitable container by completing the reaction with or without stirring. When the implementation is finished, will the small bead-like particles filtered off, washed with water and dried. The polyurethane urea produced can be used for various purposes. For example, it can be on a standard rubber or plastic mill rolled and compounded, compression-molded, extruded, injection-molded, cast into foils or as a surface coating be used.

The invention is illustrated in more detail by the following examples.

example 1

127.5 kg (281 pounds) of polybutylene adipate (molecular weight 1020) and 59.3 kg (130.7 pounds) of MDI are ^{reacted for 18 hours at about 70 °} C., whereby a prepolymer with isocyanate end groups is obtained which has an isocyanate content of 4.99 % having. The prepolymer is diluted with 37.6 kg (83 pounds) of tetrahydrofuran (16.8% of the total weight).

A high-speed mixer is used with 1250 ecm of water, 0.125 g Ultrawet K (anionic alkyl aryl sulfonate) and 10 g bentonite are charged. By stirring the mixture becomes creates a fine dispersion of bentonite.

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A portion of the diluted prepolymer of 500 g is poured into the contents of the mixer with rapid stirring and stirred for 3 minutes at room temperature. Then the contents are transferred to a vessel equipped with a stirrer and stirred overnight at room temperature. The pearl-like particles are then filtered off, washed with water and dried. The dried product consists of free flowing bead-like solid particles. Test samples are produced from a sample by injection molding at a temperature of 227 ⁰ C (440 ⁰ F) / which show the following properties:

Hardness, Shore A = 80
Shore D = 33

Modulus 100% = 56 kg / cm ² (800 psi)

300% = 105 kg / cm ² (1500 psi)

Tensile Strength, kg / cm ² (psi) = 436 (6200)

Elongation,% = 550
Deformation at break,% = 19

Example 2

A heated to 60 ⁰ C dispersion of 1880 cc of water, 0.19 g Ultrawet K, 15 g of bentonite and 0.75 g of triethylamine is charged with 900 g of the prepolymer of Example 1 was added. The reaction mixture is then stirred for 10 minutes and poured into a container, in which it is reacted ^{in an oven at 60 ° C. for a further 5 hours.} The product is filtered off, washed with water and dried. Test samples with the following properties are produced from the product by injection molding at 400 to 420 ^{0 C:}

f) Ή 1 <»/ 1 Π 2 7

Hardness, Shore A = 82
Shore D = 36

Modulus 100% = 60 (850)

300% = 108 (1540)

Tensile Strength, kg / cm ² (psi) = 420 (6000) Elongation,% = 565
Deformation at break,% = 19

Example 3

1000 g of polytetramethylene ether glycol with a molecular weight of 1000 are ^{reacted with 471 g of MDI for 18 hours at 65 °} C. to form a prepolymer with isocyanate end groups. A portion of 100 g is diluted with 20 ecm of tetrahydrofuran and poured into a suspension system of 250 ecm of water containing 0.5 g of polyvinyl alcohol at a temperature of 50 to 60 ° C. with vigorous stirring. After all of the polymer has been added, 0.1 g of Ν, Ν'-dimethylpiperazine are added, the reaction mixture is stirred for 10 minutes and then the contents are transferred to a container in which they are ^{kept at (0 °} C. for 4 hours Polymer is filtered off, washed and dried.

A sample of the polymer is molded at 220 C ⁰ (430 ° F) to a test pattern, which has the following properties;

Hardness, Shore A ■ 81
Shore D = 33

Modulus 100%, kg / cm ² (psi) = 70 (1000) 300 A, kg / cm ² (psi) = 111 (1575)

Tensile Strength, kg / cm ² (psi) = 408 (5800) Elongation,% = 620
Deformation at break,% = 28

/ J022

2252S1Q

example

A mixture of 1095 g of polypropylene glycol with a
Molecular weight of 1025 and 905 g of polypropylene glycol with a molecular weight of 400 is reacted with 1100 g of TDI (80% 2,4- and 20% 2,6-isomer) at 60 ⁰ C for 18 hours, whereby a prepolymer with an isocyanate content of
8.11% is obtained. The prepolymer contains 3.1 g of 2,2'-methylenebis (4-methyl-6-t-butylphenol) as an antioxidant.

100 g of the prepolymer are diluted with 20 cc of tetrahydrofuran and heated in a 50 ⁰ C suspension
from 250 ecm of water containing 0.5 g of polyvinyl alcohol and 0.1 g of N, N ¹ -dimethylpiperazine, poured. The mixture is stirred for 30 minutes and then transferred to a container in which it is further reacted ^{at 60 ° C. overnight.} The polymer particles are filtered off, washed with water and dried. A sample is at 204 ⁰ C
(400 ⁰ F) molded into a test sample with the following properties:

Hardness, Shore A = 94
Shore D = 47

Modulus, 100%, kg / cm ² (psi) = 70 (1000)
300%, kg / cm ² (psi) = 116 (1650)

Tensile Strength, kg / cm ² (psi) - 236 (3350)
Elongation,% = 480
Deformation at break,% = 9

Example 5

A heated to 50 ⁰ C dispersion of 1 g of hydroxyethyl cellulose in 250 ecm of water is stirred with rapid
120 g of the prepolymer from Example 1 were added. To

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For 1 minutes, 0.1 g of II, N * -dirne thy 1-piperazine is added and stirring is continued for about 10 minutes. The reaction mixture is then transferred to another vessel and kept for 5 hours kept 60 C. A sample of the dried polymer is hei 216 ⁰ C (420 ⁰ F) forngepreßt and has the following properties:

Heard choir Λ = 80
Shore D = 33

itodulus, 100%, kg / cm ² (psi) = 4G (650) 300 5. kg / cn ² (pr, i) = 84 (120O)

Tensile strength, kg / em ² = 4OP (5BOO)
Elongation, % = 530

shaping,% = 12

Example 6

A dispersion of 12.5 ng sodium auryl sulfate, 1.0 g tricalcium phosphate and 0.2 cm N, M'-ninethylpinerazine in 500 con Wasnor is mixed with 120 q -lec prepolynoren from Example 1, the 0.5 g antioxidant (50 Percent by weight of a mixture of 2,4-dinonylphenol and ethylenebis (2, O-dinonylnhenol) and 50 percent by weight of diicylphenyl phosphite) and 0.1 g of a! '"Absorber (2- (2-hydroxy-st-octylphenyl) benzotriazole) added sini, T'erset7t. Then the reaction is set for 5 hours at 55 to 60 ° C

held. The abfiItriorte, gowanchone and dried Polvner is then offered 216 ⁰ C (420 ° Γ) pit. following properties formgo) n <?

Polvner is then offered 216 ⁰ C (420 ° Γ) for a test sample

9 8 1 9/1 [) ■ /!

ZIS

Hardness, Shore A = Ho
Shore D = -

Modulus 100%, kg / cm ² (prsi) = 46 (650) 300%, kg / cm ² (pol) = 31 (1150)

Tensile Strength, kg / cm ² (psi) = 436 (6200) elongation, t = 550
Break deformation,% = 13

At. game 7

A. 15O parts PolyMthylenadipat with a molecular weight of 2000 and 0.75 parts of ^ onoallyläthers of Trinethylolpropan be with 32 parts of 2, 4-Toluylend.iisocyanat at 60 ⁰ C to a Prepolyir.o.ren nit isocyanates ^ - * groups reacted which has an isocyanate content of 2.0%,

B. 2500 parts of water containing 9 parts of bentonite IMj containing 0.3 part of an alkyl aryl sulfonate surfactant and is'erwärmt C-80 to ^0, are added to 6OO parts of Vorfcondensats described under A. Mach about 1 hour of stirring in a Waring Hischer are filtered off, the pearl-like Polynerteilchen, washed with water and dried at 7O ⁰ go G.

C. The polymer particles obtained according to B are grounded on a Standard rubber mill compounded. The composition used is given below;

Elastomer ■ '

Π te ar L ns'lure

2,2 '-Di thiobisbonz thiazol (i / RTS) 2 -Mercap to.benz th i azo 1 (MB ¹ ! ¹ ) Pu β

ZnCl ₇ complex: i from ΊΒΤΠ Cadniiinnötoarat

300 8 iii / 10 22

100 , 5 Parts Q , 0 Il 3 , 5 11 1 fO ■ I 30th I, O Il , 5 Il 0 '·

2252BiO

i). The I'O'i-ioundiorte 'let from Section C becomes 2O Ii-

nuton at IVi C (/! 37 Γ) / λι vulcanized a test specimen κ-it of the following physical properties:

Zucffestlqleit, k'j / σ-Λ "(pr.i) - I04

Elongation, °; = Π HO

ion *, Vjj /

100 ^., hq / nm ² (n: U) - 3>) {J073)

'Uxlulus ion *, Vjj / cm ² (psl) =? S5

i s ρ L ο 1.

By Unsotzuncj of 2O ^l) 1 parts poly "thylenaclipat with a molecular weight of U> no nit 37 ^Γ) share mi at 60 ⁰ C wlrcl herjentcillt a Prepolyter. Dan prepolymer which t a Isocyanatcjetial of 1.7% aiifv / is O, v; is then diluted with 246 parts of TetrahydroCuran.

Sine to 60 ° BC. erv7 ^<: irinte ^T) Lspersion of 20 parts Rentonlt and 0.05 Tel Inn Ultra '/ K in 10OO et parts of water is added to 4OO parts (360 TeL lon polymer) of the diluted Prspolymeren. The mixture was stirred for several minutes, and 0.7 tolon N, N'-I) inothylpipera3ine was added. The Reaktionsmtschunq v / ith Ln another Found ß transferred. '* And the UmsetLiimq is ^r> Hul Stundnn 6O ° C continued. Then the polymer particles are filtered off, washed with water and dried.

A 25 percent solution is made from the polymer layers ΤΙ, Π-DinethylformamLd prepared and on a glass plate Potted foils. Nar: h removal of the solvent The foils show the following lies:

JpÜ8 I ij / 1 0 2 2

Hardness, shore ? - 62

"Iodulus 100 %, kg / cm ² (pai) - 13 (250) 300 %, kc; / cn ^? · (Pri) = 25 (350)

Tensile strength, kg / cn ^A (psi) = 3Ό9 (Λ40Ο) elongation,% = 920.

3 υ 9 «ι f / ϊ ί j; ·? _Bm

Claims (16)

Claims Process for the production of a polyurethane-urea mass, characterized in that (a) a prepolymer with isocyanate end groups, which is obtained by reacting a diisocyanate with a polyol with hydroxyl end groups from the group of Polyalkylene ether glycols, aliphatic polyesters, aliphatic polyacetals and mixtures thereof is obtained, with (b) an inert suspending agent and a sufficient amount of water to form a stable suspension which can be easily stirred when all of the prepolymer has been added, reacted and (c) the mixture at high speed is stirred until discrete particles are formed. 2. The method according to claim 1, characterized in that a polyol with a molecular weight of about 500 to 5000 is used. 3. The method according to claim 1, characterized in that the polyol is a polyalkylene ether glycol, polytetramethylene ether glycol, poly-1,2-propylene ether glycol, or an aliphatic one Polyester is used. 4. The method according to claim 1, characterized in that an aliphatic polyester with a molecular weight from about 500 to 3000 is used. 309819/1022 5. The method according to claim 1, characterized in that that the aliphatic polyester used is polyethylene adipate or polybutylene adipate or an aliphatic polyacetal will. 6. The method according to claim 1, characterized in that that an aliphatic polyacetal having a molecular weight of about 500 to about 3,000 is used. 7. The method according to claim 1, characterized in that that the aliphatic polyacetal is the condensation product of an aliphatic diol having from about 4 to about 10 carbon atoms used with formaldehyde. 8. The method according to claim 1, characterized in that the diisocyanate is methylenebis (4-phenyl isocyanate) or 2,4-tolylene diisocyanate is used. 9. The method according to claim 1, characterized in that that is a molar ratio of diisocyanate to polyol in the range from about 1.2: 1 to about 5: 1 is used. 10. The method according to claim 9, characterized in that a molar ratio of diisocyanate to polyol in the range from about 1.4: 1 to about 2: 1 is used. 11. The method according to claim 1, characterized in that the inert suspending agent tricalcium phosphate, bentonite or polyvinyl alcohol is used. 309819/1022 12. The method according to claim 1, characterized in that that the suspending agent in a concentration of about 0.1 to about 5%, based on the weight of the prepolymer, is used. 13. The method according to claim 1, characterized in that the mixture with a surface-active agent is moved. 14. The method according to claim 13, characterized in that sodium lauryl sulfate or a surface-active agent linear alkyl sulfonate is used. 15. The method according to claim 1, characterized in that a monoisocyanate is used to modify the chain length is used in the production of the prepolymer. 16. The method according to claim 1, characterized in that an aliphatic or to modify the chain length aromatic monoamine is added during the reaction between the prepolymer and water. 309819/1022