DD210811A3 - PROCESS FOR PREPARING POLYOXYALKYLENE GLYCOL POLYSILOXANE BLOCK COPOLYMERS - Google Patents

Abstract

The invention relates to a process for the preparation of polyoxyalkylene glycol-polysiloxane block copolymers (PPB), which are used for the production of flexible polyurethane foams, in particular in Blockverschäumeumstechnik. It will be shown how the PPB from Polyoxylkylenglykol- and polysiloxane blocks must be assembled (size and composition of the polyether block and the polysiloxane block, ratios to each other, etc.) in order to ensure specific parameters of the flexible polyurethane foam (density, cell opening, etc.).

Description

23 5 5 07 6

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Process for the preparation of polyoxyalkylene glycol- polysiloxane block copolymers

Field of application of the invention

The invention relates to a process for the preparation of polyoxyalkylene glycol-polysiloxane block copolymers (PPB), which are used in the production of polyurethane foams, in particular elastic polyurethane "polyether-based foams, which are produced by the continuous one-shot process (slab foams - BWS), as a foam stabilizer and regulator the cell opening (SST), especially for the production of blocks of large dimension, which are free of mechanical effects, find use ,,

Characteristic of the known technical solutions

For the synthesis of the block polymers, preference is given to processes in which the starting blocks (polysiloxane, polyoxyalkylene glycol) are prepared separately and subsequently chemically linked. These methods are known in principle. The polymerization of the second component onto a starting polymer is also known. The synthesis of the polysiloxanes is generally carried out by methods known in organosilicon chemistry, such as hydrolysis, cohydrolysis and equilibration. The synthesis of the polyoxyalkylene glycols is carried out by per se Dekannte process of polymer chemistry by anionic polymerization of alkylene oxides, the end groups are optionally modified (z, B "Williamson synthesis),

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The structures of the starting materials realized in this way are very numerous.

Thus, z, B, linear or branched polysiloxanes having molecular weights between 300 and 30,000 * with different substituents on the silicon (with preference for methyl groups) and different numbers (2 to more than 30) and type hydrogen, alkoxy, halogen, carbofunctional groups of linking atoms with polyoxyalkylene glycols Homo «or copolymers of alkylene oxides are used with molar masses usually between 500 and 5,000, wherein in the copolymers, the oxyalkylene units can be arranged randomly or in blocks» Of the Alkylene oxides are preferably ethylene and propylene oxide. The coupling point to the polysiloxane is either the compound used as initiator of the alkylene oxide polymerization or a specially introduced end group of the polyoxyalkylene glycol. The variety producible by any combination of polysiloxane and polyoxyalkylene glycol Copolymer is large and is further increased by the use of mixtures (z ₀ B, several polyethers for a polysiloxane or vice versa).

For many such variants specific use-value effects of achievable foams are stressed, such as _e Β "high gas yield and good Offenzelligkeite

The claimed in examples of various inventions recipes often appear very similar, although obviously different products were obtained _e A generally recognized lack of the prior art is that the reproducibility of the synthesis of the PPB, due to the lack of reproducibility of raw materials, but also the reaction conditions and the course of the linking reaction, for the high

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Claims to the constancy of quality when used as SST in the classification procedure of the BWS hearing are not sufficient. The traceability of many patents, for. For example, USP 3867420, USP 3727491, USP 3629105, described numerous proposals is not given and you get bad batches of SST and fluctuating results in their use and must therefore sort the synthesis products according to their suitability

 This deficiency was countered by a two-step process of the PPB synthesis according to DDR-PS 125495.

However, this route requires high technical effort,

Another deficiency of the prior art is that it is not yet been able to characterize the suitability of a PPB as SST for the BWS production by measurement of chemical, physical or physico-chemical data clearly (I _e Cellular Plastics, 1973, S 99 102, on the suitability of the surface tension as a criterion: I, colloid Interface See, 24 (1967), on the suitability of the surface viscosity: Kanner, International Conference on Foamed Plastics 1978) _O There are no laboratory-scale assessment methods which allow whether an SST in BWS production leads to mechanical defects, such as, for example, block cracks, dome cracks u, a, in the PUR foam, or which block height, which foaming power or which open cell density of the foam can be achieved. This can only be determined by the large-scale fitting. Even the transferability of smaller technical equipment to larger ones is not guaranteed. There are no theoretical ideas that allow the PPB to be characterized or synthesized in such a way that they lead to an optimal foam result when used for the production of BWS.

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Object of the invention

The process of the invention is based on the object ΓΡΒ produce / in the Einstufenblockverschäumungsverfahren of flexible polyurethane foam, even at block heights of

z. B, 1 m and more _/ belt widths of 2 m and more and belt speeds in excess of 3/5 m / min and at foaming capacities of 400 m / h foam, preclude the occurrence of mechanical defects at the same time. "At the same time, a high degree of cell opening should be achieved.

JO be enough, d. h ", the foams should be well permeable to air and high gas yields of over 90 % at foam densities of less than 20 kg / m to be achieved. The PPB should lead to a high" process stability ", d, h, to a large Variability of the dosing possibility of the crosslinking catalyst and so indirectly and also directly compensate for variations in the Verschäumungsbedingungen without mechanical defects of the foam.

IVesen the invention

According to the invention the object is achieved in that PPB of the general formulas

iR · 0_7 / fSiR'o 0 7 SiR '

or GR ' ₂ S iO / "SiR ¹ 0_7 _m /""SiR ^ Oj ^ - SiR ^ G

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or

Z SiKOJT _n ι »ικ · ο

i * ¹ J7 _n

O

./SiR-GJT _n

O SiR ' ₃

in which mean:

R * are identical or different lower, optionally substituted, alkyl radicals; preferably methyl group

m whole or fractional numbers between 1 and 12, preferably between 2 and 5

η integers or fractions between 30 and 250, preferably between 40 and 120

G polyoxyalkylene glycol acetate, alkoxylate, cyanalkoxylat- or ureate radical of the general formula

- ^ fOCH ₂ CH ₂ JT - / -OCH ₂ CH (CH ₃ ) J -

R '

R "-OCOCH ₃ , -OCH ₃ , -OC ₄ H ₉ , -OCH ₂ CH ₂ CN, -OCONHR"', R "' alkyl or aryl radical

p, q whole or fractional numbers between 4 and

from corresponding polysiloxane blocks and Allyloxypolyoxyalkylenglykolblöcken be prepared in a conventional manner.

bb U / b

With regard to the avoidance of mechanical defects such as _ζ β Β β cushion / or "achieving high process stability at the BVI / S-Herste Settin g we found, surprisingly, that only such polysiloxane-polyoxyalkylene block copolymers provide results according to the invention, the (CHO) ₂ SiO and C ₂ H ,, 0 ~ units in a molar ratio of 1 to 1.3 to 1.7 and not more than 0.4, preferably 0.25 mol of free alcoholic groups, and in a molar ratio of 1 to 1 to 1 to 12 , preferably 1 to 2 to 1 to 5 from SiH ~ groups containing polysiloxanes having a molecular weight of preferably 3000 to 10,000, a maximum of 20,000, having 30 to 250, preferably 40 to 120 .Dimethylsiloxyeinheiten and from Allyloxypolyoxyalkylenglykolacetaten-, alkoxylates, -cyanalkoxylaten or , ureaten or their mixture having an average molecular weight of 2000 + 500, the 30 to 60 mol% oxyethylene and 70 to 40 mol -, & oxypropylene units and not more than 0.05 mol free alcohol have hydroxyl groups, are prepared,

When the ethylene oxide content in the PPB is not according to the invention, when it is used as SST in the BVVS, unacceptably many cracks are formed; it can even lead to the collapse of the foam. On the other hand, if the content of (CH ₂ ) ₂ SiO units is not according to the invention, the stabilizing effect as SST decreases and increasingly cell-opening substances are obtained, which can go as far as the antifoaming effect or cracks occur in the BWS blocks Oxypropylene units have no influence on the suitability of the PPB as SST.

At the same time, a maximum content of free alcoholic hydroxyl groups of 0.4 mol in the PPB must not be exceeded in order to ensure process stability when used as SST for BVVS production. It is advantageous to have a content of 0.25 mol of free alcoholic groups

3ö per mole of PPB. If the content of free alcoholic groups is too high, the cell opening in the BVVS production is insufficient.

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The aim of the invention is erreichbar./ when starting to prepare the PPB of Polyoxyalkylenglykolderivaten with a maximum content of O ₇ OS mole of free hydroxyl groups "'*' For the use of PPB as SST in BWS production, it is still necessary, for the purpose of high gas yield in the foaming process, d "h _o to reach the maximum foam height j ,, the PPB of polysiloxanes having molecular weights of

at least 300O _x at most 20 000, preferably up to 10 000 _; and from polyoxyalkylene glycol derivatives having average molecular weights of 2000 + 500. It is advantageous to maintain a molar ratio of 1 to 1 to 12, preferably 1 to 2 to 1 to 5. The polyoxysiloxanes should have 30 to 250, preferably 40 to 120, methylsiloxy units and the polyoxyalkylene glycol derivatives 30 to 60 molar equivalents. % Oxyethylene and 70 to 40 mol% oxypropylene units have »

As the polyoxyalkylene derivatives, those having various end groups such as "B", acetate, alkoxylate, cyanoalkoxylate and urea end groups can be used. Also, mixtures of the same having different end groups or different oxyethylene-oxypropylene ratio are usable

 The individual members of the mixtures may also have different molecular weights between 500 and 5000, but for the mixture a total average molecular weight of 2000 + 500 is required.

The solution according to the invention has the great advantage that in the presence of one component (polysiloxane or polyoxyalkylene glycol derivative 3G), the other can be produced selectively. Batch fluctuations of the starting materials can thus be compensated for and the production of PPBs, which have optimum properties when used as SST for BWS production, is guaranteed at all times. "

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applications

compilation 1 the polys used 4 Settin g 4 iloxanblöcke Äquilibr - Ta be 3 T Q ^ - 1 ..Verf. Zusammenste 4 «*« Μ « Herst.- C No. M D 5 «« · Ml em pm Avail. C 2 68 5 «Μ #" » .. - a C 1 2 522 12 - a C 2 2 76 5 - a + b C 3 2 75 2 4.25 - a + b C 4 2 80 5 a + b C 5 2 204 5 «Β Ψ * a + b C 6 2 65 4 mm mm a + b C 7 2 52 5 3 a C 8th 2 100 7 4.25 2 a + b d 9 5 94 5 6 3 a C 10 4 64 5 6 2.25 - a C 11 5 69 5 - « a d 12 4, 25 47, 5 a d 13 2 44 2 6 a d 14 6 36 4 a C 15 6 70 a C 16 2 75 b C 17 2 33 a 18 2 56 b 19

M. = <CH ₃ ) ₃ Si0 _{/ 2} T = CH ₃ SiO ₃₇₂ Q =

ΰ "= CII ₃ (H) SiO ₂₇₂ D = (CH ₃ ) ₂ SK)

a = Cohydrolysis of an organochlorosilane mixture with subsequent equilibration

b =. Coäquilibrierung a Organochlorsilanhydrolysatgemisches c = equilibration with conc _e H ₂ SO ₄ at 293 K d = equilibration with VVOFATIT OK 80 from 333 to 353 K

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Used allyloxypolyoxyalkylene glycol derivatives prepared by anionic copolymerization; Traces of water in the starting materials were compensated by addition of appropriate additional amounts of ethylene oxide and propylene oxide; the molar masses were determined ebullioscopically.

Ta be lie 2 28 21 51 Co Molecular weight calculated. 2250 OH mass Z Mole % 28 21 51 e 2400 2350 0.3 45 No, 25 16 54 e 2400 2100 0.03 4 1 25 25 46 e 2000 2450 0.04 6 2 36 25 53 e 2500 2800 0.02 3 3 Composition £ g OE OP% 0E 36 20 57 e 3000 2800 0.04 6 4 g / h 18 14 50 e 2750 1600 0.03 4 5 H 24 24 45 f 1600 2350 0.03 3 6 H 24 24 45 e 2400 2350 0.70 100 7 H 24 24 45 e 2400 2350 0.02 3 8.1 H 24 24 45 e 2400 2350 0.05 5 8.2 H 24 24 45 e 2400 2350 0.04 4 8.3 j e 2400 0.06 8th 8.4 G 8.5 H i k 1

Oc = Gxyethylene units OH = attached to carbon. OH CP β oxypropylene units / ^ ΟίΞ = mass% of OE Co s copolymerization: e = start allyl alcohol with NaOH

f = start butyl alcohol with KOH Eg '= groups: g = hydroxyl h = acetoxy

i = methoxy j = butoxyk = cyanoethoxy-1 = phenylurethane end groups

For the preparation of the PPB, the allyloxyalkylene glycol derivatives were used individually or in a mixture (optionally also of in

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~ ίο ~

different types produced) dissolved in toluene and azeotropically dehydrated. For reaction with the siloxane blocks having an SiH group content of less than 0.15 % , 100 g of derivative in 150 ml of toluene at a SiH group content of over 0.15 % , 100 g of derivative in 100 ml of toluene were used and a stoichiometric excess of allyloxypolyoxyalkylene glycol derivatives of 40%, based on SiH groups, is maintained *

After addition of the catalyst (hexachloroplatinic acid in isopropanol), the mixture was stirred at 353 to 373 K and after 2 to 10 min homogeneous solution, the so-called "clear point reached. The reaction is virtually complete after one hour of stirring, SiH * »groups are no longer detectable. The toluene is distilled off in vacuo, the residue is neutralized with 0.02 % monoethanolamine and can be used as SST without further treatment. In some cases, up to 40 % of a polyoxyalkylene glycol-based solvent was added to the product to lower or lower the viscosity _e to improve the dosability »

The BWS production using the PPB according to the invention as SST was carried out for density (RG) 33 kg / m, z "B _e according to the following recipe (in parts):

100 Polyoxyalkylene glycol (Systol T 112 v. VEB SYS) 38 Toluylene diisocyanate (Systenat TP 80 v. VEB SYS) 2,7 Water

0.22 tin (II) dioctoate

0.25 triethylene diamine (50% solution in glycol _e) PPB (varying amounts) as SST

In a discontinuous foaming technology, the components were mixed in an intensive mixer, with continuous technology in a mixing head,

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- ii -

To characterize the open cell OZ (air permeability, air resistance) was the back pressure

At 2 cm thick and 10 cm IO 10 cm large plates, cut out from the middle of the BWS «blocks, measured» According to the measuring equipment used, the open cell OZ at a dynamic pressure below 150 mm water column (mm water column) as "very good", up to 250 mm WS as "good", up to 400 mm VVS as "satisfactory", up to 600 mm WS as "still usable" and above 600 mm VVS as "unsatisfactory"

yes, mechanical defects such as cracks and cracks. ä », were visually determined and quantified. The crack rate "Q" indicates the number of blocks with mechanical defects per IOC of foam blocks produced in % "

The results are summarized in the following tables, with the following symbols representing each data

Polysiloxane block like »Tab» 1 in PPB Polyoxyalkylenglykolblock like «, Tab _o 2 in PPB [vololverhältnis of oxyethylene to dimethylsiloxy units in the PPB

carbon-bonded OH groups per mole of PPB viscosity of the PPB mPa _β sec parts of PPB as SST in foam starting mixture, based on 100 parts of polyoxyalkylene glycol

3 Volume weight of the polyurethane foam in kg / m height of the foam blocks in cm or % open cell, characterized by the dynamic pressure in mm water column

Crack rate in ύ (number of blocks with mechanical defects per 100 produced foam blocks)

S P MV 20 GH Visc SST 25 <G H OZ Q 30

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example 1

Variation of the molar ratio of oxyethylene to dimethyl

3 siloxy units; Formulation for volume weight 33 kg / m

Ta at Ie 3 P MV OH visco SST 6 RG H OZ Q 4 4.7 ¹ ) 1.7 0.13 3300 O ₇ 6 33.2 94 220 2 / 8th Bs ρ. S 4 1.67 0.15 6000 6 32.5 97 60 2 / ld 8th 4.7 ¹ ) 1.45 0.15 4500 O, 6 33.1 95 80 5 1.2 4 4 ₊ 7 ² ) 1.35 0.15 4200 0 / 85 33.4 90 70 3 1.3 17 6 + 7 ¹ ^ 1.35 0.18 6000 O, 6 33.1 96 200 2 1.4 4 7 1.4 0.15 3500 0 34.1 85 90 2 loO 9 1.6 7

Comparative Example;

A)

1.7 8th 6 io8 7 5 1.9 9 7 1.10 18 7 1.11 19 7

0.6 32.8 98 240 60

0.85 32.5 98 350 95

0.85 34.5 80 250 30

0.85 33.5 90 170 60

1.25 0.12 4500 0.6 35.5 85 250 55

2.2 0.15 2400 2.2 0.30 3500 0.9 0.15 2500 3.5 0.18 1300

1) molar ratio 1 to 1

2) molar ratio 0.8 to 1.2

2 3 b b U / D

Example 3

Variation of the end groups of the Polyoxyalkylenglykolreste

In each case from a batch Allyloxypolyoxyalkylenglykolen Nr, 8 gem 'Tab. 2 equal aliquots were sealed with different end groups (in one part, the OH groups were not changed 8 «1), with aliquots of a batch of polysiloxane no ₄ 4 gem. Tab. 1 implemented in the same way to PPB and in the same way as SST

3 used; MV uniformly 1.6; Recipe f. RG 33 kg / m

Ta be 5 Visc. SST H ( %) oz Q 8500 0.5 -1) üb. 2000 J) Ex. P OH 5400 0.5 105 1520 70 3.1 8.1 5,00 4900 0.5 100 72 2 3.2 8.1 + 3.2 2.5 3450 0.5 100 140 3 3.3 8.2 0.15 7000 0.5 98 240 3 3.4 3.3 0.25 5000 0.5 96 300 4 3.5 8.4 0.20 1700 0.85 ³ ) 100 * 400 4 3.6 8.5 0.40 - 'β ÜC 190 ³ ) 1) shrunken comparable hands-on product, solvent-stop ig / 2) Molar. 1 to 1 3)

therefore higher additional quantity reference value

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example

Varialion CH group content; Additional SST 0.6 parts

table

S P MV OH 16 Visc. RG H OZ Q Ex. 1 2 1.7 30 9800 32.9 90 120 4 4.1 5 3 1.55 O, 15 8000 33.1 88 80 4 4.2 4 3 1.67 24 6000 32.8 90 90 2 4. o 3 2 1.5 O, 12000 33.0 88 72 1 4.4

Verijleichsbeispiele:

4th C) 6 2 1, 7 O, 48 14500 33 5 85 1400 100 4th G 2 1 1, 7 1/ 35 8600 32 5 94 850 89 4th 7 1 1 1/ 7 1/ 8th 10200 32 0 96 630 45

example

Variation of the siloxy blocks in the PPB

Formulation for RG 33 kg / m ³ , RG obtained from 32 _f l to 33.5 SST 0.84 (with 40 % sol.); Crack rate Q below 4%

table

S P MV OH Visc , HM) OZ Bs ρ 10 4 1.35 0.15 4400 103 160 2.1 11 4 + 7 ¹ ) 1.35 0.12 3300 100 105 2.2 12 .4 + 7 ^1. ) - 1.6 0.15 2100 102 200 2.3 12 7 1.4 0.15 1300 99 130 2.4 13 7 1.6 0.13 850 105 180 2.5 16 4 + 7 ¹ ) 1.5 0.15 1500 100 120 2.6 16 7 3.1 0.15 830 103 240 2.7 - L 540 ² ) - - 100 * 150 equimolar quantities reference value 2) commercial product I forgot leichs- 1) *

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Example 5

Variation of the recipes (achievement of difference iiG)

PPB from siloxane block Nr. 4 acc. Tab. 1 and Allyloxypolyoxyalkylenglykolderivate No. ₉ 4 and 7 like «, Tab. 2 in equimolar ratio; used with 40 % polyoxyalkylene glycol based solvent; free alcoholic groups 0.15 mol%; Oxyethylene-dimethylsiloxy ratio 1.45; Visc. 2200 mPa.sec .; Recipe information for IGO parts polyoxyalkylene glycol

10 table 7 2.7 R 11 SST Ii Soll G is H OZ Q 2.7 • - 0.85 33 32.4 97 90 1.6 Bs ρ _β 2.5 3, 5 0.85 30 29.4 102 80 0.9 5 "1 Recipe Isoc. H ₂ O 3.9 9 / 0 1/0 25 24.8 98 100 2.4 5.2 38 3.2 - 1.2 24 24.1 97 60 3.5 15 5 _O 3 38 3.3 20 1.5 18 16.9 105 40 4.1 5 _O 4 35 4.3 - 1.0 29 29.1 94 70 1.8 51 2.7 - 1.2 23 23.8 96 110 2.4 5 "6 44 0.85 35 34.6 98 90 1.0 ό ο 7 45 20 5 _β 8 57 38

5.1 / 5.ο polyoxyalkylene glycol (SYSTOL T 112 v. VEB SYS) 5 _o 6 / 5.8 polyoxyalkylene glycol (SYSTOL T 114 v "ViEB SYS) Isoc. Toluene diisocyanate (SYSTENATE TP 80)

Claims (1)

235507 6 .art * in d ung aa n sp ru ch Process for the preparation of polyoxyalkylene glycol-folysilozane block copolymers of the general formulas R * SiO / "" SiR ¹ O 7 _m / "SiR» 0 7 _n SiH ' or
10 GR »SiO /" SiS ¹ O 7 / ~ 3iR ^f _o 0 7 SiR 'G c - ι - m - λ - η d G
or- R "SiO /" SiR ¹ O 7 _m / "SiR '0 7 _n /" SiR ¹ O 7 "SiR · j -", - ITi ~ c "" ~ n ~ "- In ; ι s ι SiR ' in which mean R ^{1 is the} same or different lower, optionally substituted, Älkylreste, preferably methyl radicals, ni whole or broken numbers between 1 and 12,. preferably between 2 and 5 η integers or broken numbers between 30 and 250, preferably between 40 and 120, 23550 7 6 G Polycxyalkylenglykol acetate, alkoxylate, cyanalkoxylate or urea radical of the general formula - ⁷ 3 '/ " ^0CH 2 ^CH 2 - ⁷ ρ ~ Η »-OCOGH ₃ , -OCH ₃ , -OC ₄ Hq, -OCH ₂ CH ₂ Cli, -OCONHR ¹ ", R ^tn alkyl or aryl radical ' ^: p, q whole or fractional numbers between 4 and 50, by reaction of SiH group-containing polysiloxanes,. the one. Jiolmasse from 3OOO to 10,000, at most 20,000, and 30 to 23> O, preferably 40 to 120, Dirnethylsiloxyüi η he auf en sen, κit allyloxy-polyoxyalkylene glycols of the above Formel.oder mixtures thereof, having an average molecular weight of i. | y 2000 + 5OO and 30 to GO folene-i * oxyethylene and 70 to -HO mole / i »oxypropylene Sanheiten have, in the iviol ratio 1: 1 to 1 to 12, preferably 1 to 2 to 1 to 5, to block copolymers having a mole ratio of oxyethylene to dimethylsiloxy units of 1.3 to 1.7 ", characterized in that the allyloxy polyoxyalkylene glycols per mole are not more than 0.05 mole percent, and the block copolymers per mole total not more than 0.4 mole, preferably not more than 0.25 mole, of free hydroxyl groups b contain ,,.