JPS60245623A - Production of flexible polyether-urethane foam of low gas permeability - Google Patents

Abstract

PURPOSE:To produce the titled foam having low gas permeability, low shrinkage, low density and excellent hardness, by reacting a mixture comprising a polyol, an organic polyisocyanate, a blowing agent, a catalyst and a specified foam stabilizer. CONSTITUTION:A reactant mixture comprising (A) a polyetherpolyol, (B) an organic polyisocyanate, (C) a blowing agent, (D) a catalyst, and (E) 0.5-5.0pts.wt. (per 100pts.wt. component A) polysiloxane/polyoxyalkylene copolymer, as a foam stabilizer, of formula I [wherein m is 1-300 on the average, n is 1-25 on the average, X is formula II (wherein R is a 1-10C alkylene, a/l is 3/1-1/3 by molar ratio, Y is -OR' or formula III, R' is a 1-5C alkyl, and the proportion of H is at least 50%] and, optionally, (F) a flame retardant, a crosslinking agent, etc. is poured into a mold and expanded by heating.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a flexible polyether urethane 7 ohm having low air permeability.

Soft polyether urethane foam with low air permeability has excellent compressive strength, impact resistance, and flexibility, so it has been expected to be used in applications such as cushioning materials, sound absorbing materials, and cooling materials. .

Conventionally, no effective manufacturing method has been established and large demand has not been created, so there have been expectations for the establishment of a new effective manufacturing method.

Traditionally, soft polyether urethane foam.

Generally, a polyether polyol whose main component is propylene oxide with a molecular weight of about 3000, Toryle 7 Diino 7
It has been produced by foaming and curing a mixture of art-based organic polyino/anate, blowing agent, catalyst and foam stabilizer. The soft polyether urethane foam thus obtained consists mainly of open cells and is therefore a breathable foam.

The open cell breathable foam is flexible.

It has excellent rebound resilience and is used for Kuno-Noyon materials, sound-absorbing materials, etc., but its low compression hardness makes it unsuitable for use in high-load shock absorbing materials, cushioning materials, etc.

Semi-rigid polyuretanofoams are typically used for such applications, but such foams require highly reactive polyethers, organic isocyanates as polyethers, organic polyino/anonates.

When using polyether or organic polyino/anate for regular flexible polyether urethane foams that are not highly reactive, it is necessary to use a crosslinking agent such as jetanolamine or triethanolamine, and therefore the process urethane is narrower. This has the disadvantage that it is difficult to control the reaction and it is difficult to obtain foams of uniform quality at low cost.

Therefore, it has been desired to establish an advantageous method for producing a soft polyether urethane foam with low air permeability.

Various methods have been proposed.

For example, proposals have been made to use highly reactive polyethers or organic polyinone atoms as raw materials, to increase the amount of curing catalyst, to use crosslinking agents, etc., but these methods do not provide a stable form. However, even if it can be obtained, the process range will be extremely narrow.

Another method is as disclosed in JP-A-57-31976, in which closed-cell polyurethane foam is prepared in the first step and then crushed in the second step to obtain a foam with low air permeability. There is. however,
This method has the disadvantage of requiring two steps.

It is an object of the present invention to provide a process for making a low air permeability polyether urethane foam that does not have the disadvantages of the conventional low air permeability 7 ohm process.

Thus, the present invention provides a reaction mixture comprising a polyether, an organic polyinonoanate, a blowing agent, a catalyst, and a foam stabilizer suitable for use in producing polyurethane foam from a polyether polyol and an organic polyino/anate. , in the method of producing polyurethane foam, as a foam stabilizer (2 formula% formula%) [where m has an average value of 1 to 300, n has an average value of 1 to 25
X is the structure fR(C2H40)a(C3H60)bY] (R is 1 to
It is an alkylene group containing 10 carbon atoms, a/b is a molar ratio of 3/1 to 1/3, and Y is -OR', -0CR
, -0COR', R' is a hydrogen atom or an alkyl group having a carbon 1110 prime number of 1 to 5, and the proportion of hydrogen atoms is 50% or more)] The object of the present invention is to provide a method for producing a soft polyether urethane foam, which is characterized by using coalescence to obtain a foam that has extremely low air permeability and does not shrink.

By using the polynoloxa/-polyoxy/alkylene copolymer shown in the claims as a cell stabilizer, the present invention uses general-purpose raw materials, produces stable open cells in a wide process range, and has excellent air permeability. It is characterized by a low foam.

The foam stabilizer that can be used in the present invention is a polynoloxane-polyokine alkylene copolymer.

Formula % Formula %) [where m has an average value of 1 to 300, n has an average value of 1 to 25, and X has the structure fR(C2H40)a(C3H
60) bY] (RUI~10 is an alkylene group containing carbon atoms, a/b is a molar ratio of 3/1~]/3,
YI'1-OR', =OCR', -〇COR', and R' is hydrogen atom 11; (O or an alkyl group having 1 to 5 carbon atoms, and the ratio of hydrogen atoms is 50 or more) ].

In this poly/loxane-polyoxy/alkyleno copolymer, the number of dimethylfuroxane units is determined by m and can take an average value of 1 to 300.

It is preferable to take an average value within the range of 20-200.

It can take an average value of 1 to 25 depending on the number of methyl polyoxy/alkylene units, but preferably 3 to 1.
It is better to take the average value within the range of 5.

The polyoxy/alkylene moiety of the boria 0 xane-polyoxoalkylene copolymer is defined by the symbol X and has the structure -
R(C2H40)a(C3I(60)bY) In this structure, Ri-j is an alkylene group containing 1 to 10 carbon atoms, preferably an alkylene group containing 2 to 5 carbon atoms. It is good to be.

The polyoxyalkylene portion of the polysiloxane-polyoxyalkylene copolymer consists of oxyethylene groups and mequinbrobylene groups, and the total amount is determined by a + b. This takes an average value of 3 to 100, but preferably an average value within the range of 5 to 60.

It is the terminal IiY of the polyoxyalkylene moiety.

These are -OR', -0CR' and -0COR' groups (R' is a hydrogen atom 11) or an alkyl group having 1 to 5 carbon atoms, and the proportion of hydrogen atoms is 50 or more. The structure consists of 70 cm or more.

In the present invention, the bolinkoxane-polyoxy/alkylene copolymer used as a foam stabilizer and the method for producing them are disclosed in Patent Publication No. 40-12190 entitled "Process for producing polyurethane 7A-me" by D. Beyseau and N. Pater. ．． and Japanese Patent Publication No. 43-16399.

Therefore, the polyoloxane-polyoxane used in the present invention
The alkylene copolymer is a known compound, and it is also possible to use this compound as a foam stabilizer for flexible polyether urethane foam.
1.6399 Although the VC disclosed herein is different from the technology of the present invention and the above-mentioned two patent publications, the reason thereof will be shown below.

Japanese Patent Publication No. 40-12190 discloses a polysoloxane-polyoxy/alkylene copolymer which is characterized by the structure of the foam stabilizer used in the present invention, in which the terminal group of the polyoxy/alkylev moiety is a hydroxyl group. Although the general formula shows that a polymer can exist, the detailed description and examples of the invention do not show a copolymer with a hydroxyl group at the end, but a copolymer with an alkoxy group at the end. The foam produced is also a general air-permeable foam, and there is no disclosure whatsoever regarding the production of the low-air permeability foam of the present invention, which is different from the present invention.

Next, claim (2) of Japanese Patent Publication No. 43-16399
discloses a boria-oxygen-polyoxy-alkylene copolymer similar to the present invention, which has a hydroxyl group at the terminal, and also shows examples using this copolymer, but the purpose of using this copolymer is foam stability. It is possible to produce a stable premix for polyurethane foam (see page 1, right column, lines 24 to 28 of the same publication, page 2, left column, top line 1 to line 6 of the right column). and page 10, left column last line to right column 8
However, there is no disclosure at all about the production of a low air permeability foam with a single return, which is different from the present invention.

Other patents of similar technology using a poly/loxa/-polyoxyalkyleno copolymer having the same terminal hydroxyl group as the present invention as a foam stabilizer include: Japanese Patent Publication No. 52-13239;
3511.9. JP-A-55-1.04330. Japanese Patent Application Publication No. 5
7-31.976, JP-A-57-195722, etc., but the structure and purpose are different from the present invention.

That is, the oxyalkylene portion of the JP-B-52-13239il-i copolymer is only an ethylene oxide portion, and is intended for the production of rigid urethane foam.

Special Publication No. 53 35119 is hard urethane foam A for casting.

- JP-A-55-104330 is for the production of waterproof (water-leak-resistant) open-celled polyurethane foam ring material, JP-A-57-31976
The purpose of this method is to produce closed-cell polyurethane/fumeme and to produce a polyurethane-filled/ring material by crannulating this.

Furthermore, JP-A-57-195722 is different in that it is aimed at producing a rigid urethane foam, whereas it is aimed at producing the low air permeability flexible polyurethane foam of the present invention.

The amount of polynoroxane-polyoxy/alkylene copolymer used in the process of the present invention should be in the range of 0.5 to 50 parts by weight per 100 parts of polyether polyol, although higher amounts may be used. It may also be used in small amounts.

In addition to the above-mentioned polyether polyol, organic polyiso/anate, catalyst 2 blowing agent and foam stabilizer, flame retardant, crosslinking agent 2 polysiloxane-polysiloxane which is outside the scope of the polyoloxane-polyoxane/alkylene copolymer defined in the present invention It may also contain an oxyalkylene/copolymer. An example of such a bubble stabilizer is the general formula R3i[o(R' 5iO)p(CnH+
q]R'' and a copolymer of the general formula %).

However, in the above formula, R is a hydrocarbon having 1 to 6 carbon atoms, and R'
is hydrogen or a hydrocarbon having 1 to 10 carbon atoms.

p + q , r r 8 , u are positive integers, and t
I′iO or a positive integer, and n is an integer of at least 2.

The final foamed composition of the present invention comprises large amounts of (1) a polyether polyol and (2) an organic polyinonoanate.

(3) a small amount of blowing agent, (4) a catalytic amount of catalyst, and (5) a small amount of polynoloxane-polyokynealkylene copolymer sufficient to provide an open-cell, low air permeability, flexible urethane foam, and optionally (6) Contains appropriate ingredients.

The production of flexible urethane foams with open cells and low air permeability by using polynoloxanes/polyoxyalkylene copolymers as defined herein has not been possible in the past when other polynoloxanes/polyoxyalkylene copolymers were used. This is unique considering that a foam with communication and high air permeability can be obtained.

It has further been found that the present invention provides a 7 ohm soft polyether polyurethane with high hardness and low density.

The open-cell, low-air permeability flexible polyurethane foam composition of the present invention is useful in a wide range of well-known fields. For example, gas, liquid loca materials, and sound absorbing materials.

It can be used as a heat insulating material, a sealing material, a shock absorbing material, etc.

Compression Hardness J as defined herein and shown in the Examples below
Measured using the method specified in IS K6401. Furthermore, if a method based on this method is used in which the compression speed is increased, the properties as a shock absorbing material will be better exhibited. Also,
The closed cell ratio is measured using an air comparison type hydrometer shown in ASTM D2856-7.0. Breathability is (Jou
rnal of Ce1lularPlastics
1965 Vol. 1 & i p200-216).

<Example 1> After thoroughly mixing the following components, the mixture was placed in a box measuring 30 x 30 x 30 m, and after foaming was completed, the mixture was placed in a Cure Open/to be cured.

molecular weight 3000. Hydroxyl value 50 Trilenethynonanate (80/20) 52.1 Copolymer A10 Water 4.0 Triethylenediamine/dipropylene glycol 33/67 (weight ratio) 02 mixture N-ethylmorpholine 0.2 Octylic acid -Tin 03 Example 2 and Comparative Examples 1 to 3 Instead of copolymer A, the same weight parts of copolymer B were used.
, C, D, E was repeated.

Copolymer Average Formula A (CH3)3Si [(CH3)25iO)7゜CC
H3X5iO), 5i(CH3)3X: -C1H6
(-C2H40hT-(=C3H617g-OHB (
CH3)asi[(CHs)2SiO)7o(CH3X
SiO)7Si(CH3)3X: -C,H6-(C2
H40)-π-(C3H60)7-OR where R is a hydrogen atom or a methyl group and the hydrogen atom is 80$D (CH,)3
SN:(CH3)25+0)5oI:CH3X5iO]
, 5t(CH3)iX: C3Ha (C2H40)
24(C3H,0)-VOCH.

E (CH,)3si((CH3)2SiO)+5(C
H3XSiO)ysi(CH3)3X: -C,H,-
(C2H,0iOH) The physical properties of the foam obtained in the above example were measured and the values shown in the following table were obtained.

As shown in the above table showing the results of the above examples, Example 1 shows the results obtained by using the foam stabilizer (A) of the present invention in which all the terminals of the polyoxyalkylene moieties of the copolymer are hydroxyl groups. This shows that it has low air permeability. Example 2 shows the results obtained by using the foam stabilizer (B) of the present invention, in which 80% of the terminal groups of the polyoxyalkylene moiety of the copolymer are hydroxyl groups and 20% are methocino groups. It has been shown to have low air permeability.

In Comparative Examples 1 and 2, a foam stabilizer (C is a foam stabilizer for general flexible polyether urethane foam) different from the foam stabilizer of the present invention in which the terminal group of the polyoxyalkylene moiety of the copolymer is only a methoxy group instead of a hydroxyl group. D is a foam stabilizer for general rigid polyether urethane foam). No good results were obtained.

Comparative Example 3 shows the results obtained by using a foam stabilizer (E) different from the foam stabilizer of the present invention in which the polyoxyalkylene portion of the copolymer is composed of a polyethylene oxide portion, but sagging occurred during foam production. 2. Good results were not obtained as in the present invention.

Claims (1)

Claims: From a reaction mixture comprising a polyether, an organic polyiso/anate, a blowing agent, a catalyst and a foam stabilizer suitable for use in producing polyurethane foam from a polyether polyol and an organic polyynon anate. , in the method of producing polyurethane foam, as a foam stabilizer (1 formula % formula %) [where m has an average value of 1 to 300, n has an average value of 1 to 25
X has the structure -E-R(C2H40)a(C3H60)bY] (R is an alkylene group containing 1 to 10 carbon atoms, and a/b is a molar ratio of 3/1 to 1/ 3 and Y is -OR'. -0CRnee0COR' and R' is a hydrogen atom or carbon number 1
~511100 alkyl group, and the ratio of hydrogen atoms is 50 coefficients or more)] By using a polysiloxane-polyoxyalkylene copolymer shown as A method for producing a soft polyether urethane foam characterized by obtaining a foam that does not shrink.