CS198741B1 - Method of producing polyurethan formed elements - Google Patents

Description

The invention relates to the production of molded articles from polyurethane integral foams.

SUMMARY OF THE INVENTION The present invention provides for the preparation of molded panels of resilient integral polyurethane foam containing a certain proportion of diol and etherdiol. The material can be used in the most diverse branches of industry / furniture, automotive, refrigeration, shoe industry, etc./.

In particular, aa aims to replace 1,4-butanediol in reoeptures for the preparation of integral polyurethane foam products with a mixture of diol and etherdiol.

Integrally polyurethane foam has found widespread application in industry, especially for the evolution of increased durability, improved mechanical properties, reduced number of manufacturing operations, while achieving the final shape of the product.

The most well-known technology for the production of polyurethane foam articles consists in over-dosing and mixing the streams of tempered fluids and in pouring the homogenized mixture into a heated and separated mold. One of the reaction streams is called the isocyanate and consists of either chemically pure dilzoocyanate or so-called diocyanate. of a prepolymer, which is a chemically reacted mixture of an excess of diolocyanate e polyol such that the reaction product has a certain amount of free isocyanate groups. The second component is called polyol and consists of polyether polyols (or polyether polyols) of a low molecular weight diol, blowing agents, catalysts and a foam stabilizer.

The function of the low molecular weight moiety (butanediol epoxy) 1,4 is to reduce prlemer198 741

198 741 of the molecular weight of the reaction system, thereby generating a greater amount of urethane linkages which bear the physico-mechanical properties of the resulting polymer. The greater the amount of butanediol used, the higher the hardness and strength of the products, but the lower the ductility, and especially the lower bending resistance. Therefore, the amount of butanediol needs to be carefully controlled by the physical and mechanical properties of the products according to the purpose they serve and at the same time polyaddition reaction.

If butanediol is replaced with a low molecular weight diol, e.g. monoethylene glycol, products having a higher hardness and lower bending resistance at low temperatures are obtained. When using higher glycols, the hardness of the product does not reach 70 ° Sh A, thus limiting the range of application. And other physico-mechanical properties are not at the same level as using butanediol. By using propylene glycols as crosslinkers of the polyurethane diapers, products of very low physico-mechanical values are obtained and, in addition, the characteristic reaction times of the foam have been prolonged by an order of double.

The preparation of butanediol proceeds through a demanding synthesis, therefore its cost is practically three times higher than that of other low molecular weight diols or ether diols, which adversely affects the product wall.

The method of preparing products made of polyurethane diapers, so-called " in a prepolymer manner. It consists in the preparation of two reactants, namely:

and / a prepolymer prepared by reacting an excess of diisocyanate (most commonly 4.4 * diphenylmethane disisocyanate) and a linear polyol having a molecular weight of 2000 (polyetherpolyol or polyetherpolyol) - component A.

b) component B is a homogenized mixture of linear polyol, branched polyol, catalysts, blowing agents, and stabilizers of the pan, characterized in that it contains 7 to 16 wt.

% low molecular weight diol with two backbone carbons and 2 to 14 wt. % etherdiol having 4 to 6 carbons in the backbone.

The components thus prepared and tempered to the prescribed temperature are mixed and, after homogenization, poured into a heated and separated form. The material fills the mold cavity and reacts to the article.

The advantage of using diol and etherdiol as a component of the polyol component is that their suitable combination and total amount in the reaction eyetem can be very sensitive to change the physico-mechanical properties of polyurethane diaper products in the glowing direction, particularly in hardness, strength, structural strength, and durability against odleranlu.

By using diol and etherdiol relative to light chemical configuration, it is possible to reduce the levels of the reaction catalysts while maintaining the characteristic reaction times of the onset and the foaming time, while the technologically necessary start, foaming and crosslinking times are very well aligned. Practically, this means that the start of the polyaddition reaction begins in about 5 to 10 seconds after the components have been homogenized, the foaming time takes about 6 and 8 times the start time and the zwitters. characterized by stickiness, occurs after 8 to 10 times the start time. This harmonized, quiet foaming time ensures perfect filling of the rugged mold cavity and allows air to be expelled from the mold. The material skeletons up to <sp #

198 741 Breakage and filling of the mold cavity. In this way, harmonized reaction times will ensure high production of high-quality moldings, as they allow molding of moldings in as little as 3 to 5 minutes. The preparation of the dolol and the etherdol to the polyols appropriately reduces the total molar weight of the system to a desirable degree and thereby ensures the generation of the necessary amount of urethane bonds, which are noaitelml of the physico-mechanical properties of the resulting polyurethane. Tables 1 and 2 show the effect of the amount and the mutual combination of ether and ether on the physico-mechanical properties.

The accompanying examples of embodiments of methods for producing polyurethane elongates using a mixture of dolol and ether are described in more detail below.

Example 1

The reaction mixture aa is prepared as follows:

1. Component A: 85 h.d. a polyether polyol prepared from adlpic acid, butanedol, monoethylene glycol and dlethylene glycol having an average molecular weight of 2,000 and OH of the number 53 to 59 mgKOH / g is heated to 60 ° C and poured into 100 h.d. 4,4 'diphenylmethane diisocyanate. The mixture was allowed to react for 24 hours. A reaction product is obtained containing 15% free KCO groups.

2. Component B is prepared by weighing and homogenizing:

68.8 h.d. linear polyether polyol of mol. weight 2 000 9.0 h.d. of a branched polyether polyol having an OH number of 50 to 55 mgKOH / g

13.0 h.d. monoethylene glycol 5.0 h. d. dletylénglykolu

O, 75h.d. A 33% solution of triethylenedlamine in diethylene glycol

2,0 h.d. methylene chloride

0,8 h.d. medlinic oil

0,05h.d. dlbutylcínlaureátu

0.3 h.d. waters

Component A is brought to 45 ° C, component B to 50 ° C. The components are mixed in a ratio of A: B = 100: 57 and poured into the mold cavity, which is slightly reacted to give a material which, at a specific weight of 550 kg / m, has the following physicochemical properties:

tensile strength 8.5 MPa ductility 415% hardness 75 ° Sh A tear strength 23 N / mm abrasion resistance 24 mg module 100% 2.9 MPa

Example 2

PTedpolymer is prepared from a mixture of linear polyetherether polyol with an average mol. weight 2,000 by heating aa to 60 ° C and pouring while stirring to 70 ° C hot 4,4'-diphenylmethane diisocyanate. The polyol and the isocyanate are milled in a weight ratio of 80: 100.

The prepolymer obtained contains 16% free HCO groups.

The polyol component is prepared by mixing by homogenizing the following components:

198 741

64.25 h.d. linear polyether polyol having an OH number of 53 to 59 mgKOH / g

15 _e O hd, a branched polyether alcohol having an average mol. weight 2 OOO

11.0 hd monoethylene glycol 9.0 hd triethylene glycol 0.35 hd crystalline triethylenediamine 0.4 hd water the pre-polymer is heated to 40 ° C, the polyol component to 45 ° C and both aa zhoaoge by agitating in A to B ratio with 100 sec. 59. By reacting in the form heated to 40 ^ϋ 0, a material of 3 kg has a weight of 600 kg / m and a low tensile tensile strength of 8.4 MPa tensile strength 470% hardness 72 ° Sh A further tearing 24.5 N / mm modulus 100% 2.7 MPa abraded 26 mg

Example 3

Component A is prepared by chemical reaction "between 60 ^and C Hot-diphenylmethane 4,4 'diisokyanátoa and 60 ^is 0 hot polyether polyol prepared from propylene oxide of prlenernej mol. weight 2,000 so as to contain 15% of the free NCO groups.

Set B is a homogenized laugh by mixing

12.0 h.d. linear polyether polyol, prepared from propylene oxide with an average molecular weight of 2 000

62.6 h.d. of branched polyether polyol, prepared from propylene oxide of average mol, of a weight of 4 000 and OH of the number 34 to 38 mgKOH / g

14.0 h.d. monethylene glycol 4.0 h.d. dletylene glycol 0.2 h.d. octoate of tinate

0,6 h.d. Of a 33% solution of triethylene amine in dl-propylene glycol 0.2 h.d. waters

5,5 h.d. trlohlorofluoromethane &lt; 0.9 h.d. DC-195 Sniper

By reacting the circulation of the components in the ratio A »B« · 100 s 60, a material is obtained which, at a specific weight of 600 kg / m, has the following physically-mechanical values * modulus 100% 3.3 MPa tensile strength at 6.9 MPa tensile strength 335 <t>

74 ^e Sh A hardness in further tearing 12.5 H / mm abrasion resistance 87 mg

198 741

Sabo 1 Effect of mcaeetylene glycol and diethylene glycol on the physical soft properties of polyurethane foams

Kemblaádia strength v taba / Bar / íažnoet /% / Tear strength / N / mm / hardness / ®Sh / Prelaaovanie / Ke / BBG BBS 10 4 73 457.1 I83 68.5 7835 10 7 73 4573 21.2 70.6 47.70 10 10 73 436.1 233 713 32.66 12 . 4 73 4223 203 72 3 80 36 12 7 73 4283 22.5 74.7 9737 12 10 73 4093 233 753 81.78 14 4 83 4103 233 77.7 99.51 14 7 8 _S 5 425.7 243 793 101.28 14 10 73 4063 23.8 73.8 42.33

Tab, ·, 2 ÚSintA jstmoethylene glycol and triethylene glycol on the physical-fire properties of polyiwsan foams

Koíflbiíiáels Strength Ductility Structural Hardness Erelamation in baba fortress

MBS a) BG / MRE, / Í 1% / M / Iutta / / ®Sh / / Kc / 10 4 8.2 469.3 183 72.3 28.98 10 7 8.0 4943 233 70.3 26,05 10 10 Θ3 502.2 223 69.3 5333 12 4 8.2 438.1 22.3 753 69.20 12 7 83 448.6 243 733 103.06 12 10 / ₀ 1 452.4 22.4 72 ₉ 3 6935 14 4 7 <3 4413 253 803 60.43 14 7 7 _S 6 429.2 27.2 78.0 100.35 14 10 7.7 4213 223 763 71.21 P Η B D M L ΐ H L L L B Z 0

Claims (1)

The production method of molded polyurethane moldings. By means of the prepolymer β method, a wide variation in the physico-mechanical properties of the products is achieved by the mixing of the homogenized polyol component with 7 to 16 wt. % of a low molecular weight diol with two main carbon chains and 2 and 14 wt. % of etherdiol β by 4 to 6 carbons in the blavama chain.