JPH0790102A - Urethane foam manufacturing method - Google Patents

Abstract

(57) [Summary] [Object] The present invention aims to provide a method for producing a urethane foam. [Structure] The structure of the present invention is characterized in that a surfactant comprising a non-hydrolyzable linear siloxane-polyoxyalkylene (AB) n block copolymer is used as a foam stabilizer of a urethane foam. Is a manufacturing method. [Effect] The method for producing a urethane foam, which is characterized in that the surfactant having a specific chemical structure of the present invention is used as a foam stabilizer for a urethane foam, is excellent in super-foaming power, holding power for fine bubbles, etc. It is stable, has no shrinkage, no cracks, etc., and there is no variation in the bubble stabilizing effect, which is superior to conventional products.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a urethane foam. More specifically, the present invention is characterized in that a surfactant having a specific chemical structure is used as a foam stabilizer for urethane foam. Regarding the method.

[0002]

2. Description of the Related Art Urethane foams include hard type, semi-hard type, soft type, integral type, and integral type depending on the purpose of use.
There are various types such as foamed polyurethane elastomer,
Usually, each of them is obtained by foaming together with the formation of a polymer by a polymerization reaction, which is mainly composed of a compound having an active hydrogen atom such as isocyanate and a hydroxyl group, for example, a polyol, a catalyst and a bubble stabilizer. In the production of urethane foam, the raw materials excluding the cell stabilizer mainly control the polymer structure with respect to mutually complicated chemical reactions, but it is said that the cell stabilizer participates in a physical phenomenon and controls the cell structure. The physical phenomenon relates to the effect of surface activity due to static / dynamic surface tension, surface viscoelasticity and the like. A commonly used cell stabilizer is a block copolymer of polyether and polysiloxane. The chemical structure of this copolymer is a linear type in which polyether and polysiloxane are bonded at one end of each molecule, a branched type in which side chains are bonded, or a bond between polyether and polysiloxane. Part is Si-
There are various types such as an O-C hydrolyzed type and a Si-C non-hydrolyzed type. Especially as a new structure,
Japanese Examined Patent Publications No. 52-24078 and No. 54-1840 propose linear type repeating structures, and Japanese Examined Patent Publication No. 57-14797 proposes a non-hydrolyzable type. Attention has been focused on its usefulness such as superior foaming power and holding power for fine bubbles as compared with the above-mentioned bubble stabilizer.

However, in the above-mentioned conventional techniques, there is a demand for a bubble stabilizer having more stable performance because the foam state is not stable and there are variations in the bubble stabilizing effect such as shrinkage and generation of cracks.

[0004]

SUMMARY OF THE INVENTION In view of such circumstances, the present invention is a further improvement of the conventional cell stabilizer, which is excellent in foaming power and holding power for fine foam, and has a stable foam state.
It is an object of the present invention to provide a method for producing a urethane foam, which is characterized by using a cell stabilizer having more stable performance, which is free from shrinkage, cracking, and the like and has no fluctuation in the cell stabilizing effect.

[0005]

[Means for Solving the Problem and Its Action] In order to find a silicone compound and other components effective as a cell stabilizer component during the production of urethane foam, the present inventors have found that silicone compounds having various chemical structures and other components. In addition, experiments were carried out on these combinations, and it was found that it was effective to use a surfactant having a specific chemical structure in the foam stabilizer of urethane foam, and the present invention was completed.

That is, the present invention has the general formula

[Chemical 2] (In the formula, R represents a monovalent hydrocarbon group containing no aliphatic unsaturation, n is an integer of 2 to 4, a is an integer of at least 6, b is an integer of at least 4, c is an integer of at least 2, Y represents a divalent organic group bonded to an adjacent silicon atom by a carbon-silicon bond and to a polyoxyalkylene block by an oxygen atom,
The average molecular weight of each siloxane block is about 400 to 1
The average molecular weight of each polyoxyalkylene is 200 to about 10,000, and the polyoxyalkylene block has an average of about 50 ethylene oxide.
To about 80% by weight, the siloxane block making up about 10 to 95% by weight of the copolymer, the polyoxyalkylene block making up about 90 to 5% by weight of the copolymer, and the block copolymer at least About 1,20
A urethane foam characterized in that a surfactant comprising a non-hydrolyzable linear siloxane-polyoxyalkylene (AB) n block copolymer having an average molecular weight of 0) is used as a foam stabilizer of urethane foam. Is a manufacturing method.

Examples of R in the above formula include a hydrogen group,
Alkyl group (eg, methyl group, ethyl group, propyl group,
Butyl group, pentyl group, hexyl group, octyl group, decyl group, dodecyl group, octadecyl group, eicosyl group, etc.), aryl group (eg phenyl group, naphthyl group etc.), aralkyl group (eg benzyl group, phenylethyl group etc.) , A tolyl group, a xylyl group, a cyclohexyl group, a halogenated alkyl group (a trifluoropropyl group, a chloropropyl group, etc.) and the like, and a methyl group is particularly preferable.

The group Y is a divalent organic group having one end bonded to a silicon atom and the other end bonded to an oxygen atom, that is, it is bonded to an adjacent silicon atom by a carbon-silicon bond, and a polyoxy group is bonded via the adjacent oxygen atom. A divalent organic group bonded to an alkylene block, for example, the following formulas: -R'-, -R'-CO
-, -R'-NHCO-, -R'-NHCONH-R "
-NHCO- or -R'-OOCHN-R "-NHC
O- (in the formula, R'is a divalent alkylene group such as ethylene group, propylene group, butylene group, etc., and R "is 2
Valent alkylene group, for example, exemplified group or a divalent arylene group with respect to R ', for example _{-C 6 H 4 -, - C} 6 H 4
_{-C 6 H 4 -, - C} 6 H 4 -CH 2 -C 6 H 4 -, - C
₆ H ₄ —CH (CH ₃ ) —C ₆ H ₄ — and the like, and particularly preferably a phenylene group).

Suitable examples of radical Y are: --C
_{H 2 CH 2 -, - CH} 2 CH 2 CH 2 -, - CH 2 CH
_{(CH 3) CH 2 -,} - CH 2 CH 2 CH 2 CH 2 -,
_{- (CH 2) 2 CO -} , - (CH 2) 3 NHCO -, -
_{(CH 2) 3 NHCONHC 6 H} 4 NHCO- or -
_{(CH 2) 3 OOCNHC 6 H} 4 NHCO-. The most preferred groups Y is a divalent alkylene group, in particular _-CH 2 _CH 2 C
H ₂ - or _{-CH 2 CH (CH 3) CH} 2 - it is.

The above linear polysiloxane-polyoxyalkylene block copolymer has a single or two or more polyoxyalkylene compounds having a reactive end group, and an end group which reacts with the reactive end group of the compound. Alone or 2
It can be produced by reacting one or more polydialkylsiloxanes.

The linear polysiloxane-polyoxyalkylene block copolymer used in the present invention is represented by the above formula (1), in which R, Y, a,
The molecular weights of b, c and n, and each block and the whole copolymer are in the range defined above. Further, the polyoxyalkylene block in the formula (1) cannot obtain a cell stabilizer with stable performance unless it contains about 50 to about 80% by weight of ethylene oxide on average. That is, when the ethylene oxide is less than this, the foam is not formed, and when the ethylene oxide is more than this, the foam shrinks and cracks, and the product value is significantly reduced.

The block copolymer used in the present invention may be used alone or dissolved in water or various organic solvents (ethanol, isopropyl alcohol, ethylene glycol, propylene glycol, pentane, hexane, octane, nonane, decane, toluene, xylene, etc.). To use.

Further, the surfactant having a specific chemical structure used in the present invention may further include a lower alcohol, if necessary.
Water, antioxidant, preservative, polyalkylene glycol,
A conventional block copolymer of polyether and polysiloxane, which is used as an organic surfactant or a bubble stabilizer, may be blended. These must be used under qualitative and quantitative conditions that do not impair the object of the present invention.

[0014]

EXAMPLES Next, the present invention will be explained based on examples, but the present invention is not limited to these. In addition,
Prior to the examples, the evaluation methods are shown below. Semi-rigid urethane foam test 100 parts by weight of polyol mixture, 22.3 parts by weight of TDI (mixture of about 80% by weight of 2,4-tolylene diisocyanate and about 20% by weight of 2,6-tolylene diisocyanate), TMBDA (N, N). , N ', N'-tetramethyl-1,3-butanediamine) 0.1 part by weight, nickel acetyl acetate 0.2 part by weight, and a surfactant 2.0 parts by weight in a container, and a turbine type agitator. Using a machine, stir at room temperature, pour into a 300 mm × 300 mm × 300 mm wooden mold and cure at 125 ° C. for 10 minutes to complete the foam. Here, the polyol mixture has a molecular weight of about 3
Propylene and a glycerol oxide adduct triol having a hydroxyl number of about 56 and about 80% by weight of acrylonitrile and 55 parts by weight of a graft copolymer having a hydroxyl number of about 45, a molecular weight of about 700 and a hydroxyl number of about 45%. The glycerol starting propylene oxide adduct triol having about 240 comprises 20 parts by weight and the poly-ε-caprolactone diol having a molecular weight of about 530 and a hydroxyl number of about 212 comprises 25 parts by weight. At this time, the foam retention rate and foam density are measured by changing the type of surfactant. Flexible urethane foam test 100 parts by weight of polyether polyol, 5.0 parts by weight of water, 0.3 parts by weight of TEDA-L33 (manufactured by Tosoh, 33% dipropylene glycol solution of triethylenediamine), 0.13 parts by weight of tin octylate, Add 1.2 parts by weight of surfactant to a container and use a turbine-type stirrer.
After premixing at 00 rpm for 40 seconds, add TDI stoichiometry (NCOindex 100) and stir for 5 seconds,
400 (W) x 400 (L) x 1 which was preliminarily adjusted to 40 ° C
It is poured into an aluminum mold of 00 (H) mm to form a foam. About 100 seconds after adding TDI, the filling of the mold is completed. Then, the mold is placed in a hot air oven at 170 ° C. for 8 minutes for curing to obtain a flexible polyurethane mold foam. At this time, the physical properties of the foam are measured according to JIS-6401 by changing the kind of the surfactant.

Synthesis Example of Linear Polysiloxane-Polyoxyalkylene Block Copolymer Synthesis Example 1 Dimethallyl was placed in a 1000 ml three-necked flask equipped with a mechanical stirrer, condenser, thermometer and nitrogen inlet. Polyether

[Chemical 3] 250g, toluene 350g, and platinum content 20p
Chloroplatinic acid was added so that it would be pm. The mixture was charged with dihydropolydimethylsiloxane at a rate to maintain the temperature at 80-100 ° C.

[Chemical 4] 57 g were added slowly. The end of this reaction was determined by the AgNO ₃ test for SiH being negative. The reaction mixture was then neutralized with NaHCO ₃ , filtered and the solvent was removed on a rotary evaporator at 50 ° C./1 mmHg to give the following formula:

[Chemical 5] As a result, 292 g of a linear polysiloxane-polyoxyalkylene block copolymer having a molecular weight of 45,000 was obtained.

Synthesis Example 2 Dimethallyl polyether

[Chemical 6] 200 g, dihydropolydimethylsiloxane

[Chemical 7] 125g, 350g toluene, and platinum content 20p
When the same operation as in Synthesis Example 1 is performed using a platinum-based addition catalyst so as to give pm, the following formula:

[Chemical 8] As a result, 309 g of a linear polysiloxane-polyoxyalkylene block copolymer having a molecular weight of 53,000 was obtained.

Synthesis Example 3 Dimethallyl polyether

[Chemical 9] 210 g, dihydropolydimethylsiloxane

[Chemical 10] 276 g, toluene 350 g, and platinum content 20 p
When the same operation as in Synthesis Example 1 is performed using a platinum-based addition catalyst so as to give pm, the following formula:

[Chemical 11] 283 g of a linear polysiloxane-polyoxyalkylene block copolymer having a molecular weight of 69000 was obtained.

Synthesis Example 4 Dimethallyl polyether

[Chemical 12] 180 g, dihydropolydimethylsiloxane

[Chemical 13] 156g, 350g toluene, and platinum content 20p
When the same operation as in Synthesis Example 1 is performed using a platinum-based addition catalyst so as to give pm, the following formula:

[Chemical 14] Thus, 318 g of a linear polysiloxane-polyoxyalkylene block copolymer having a molecular weight of 46,000 was obtained.

Synthesis Example 5 Dimethallyl polyether

[Chemical 15] 83.3 g, and

[Chemical 16] 103.9 g, dihydropolydimethylsiloxane

[Chemical 17] 118g, 350g toluene, and platinum content 20p
When the same operation as in Synthesis Example 1 is performed using a platinum-based addition catalyst so as to give pm, the following formula:

[Chemical 18] As a result, 290 g of a linear polysiloxane-polyoxyalkylene block copolymer having a molecular weight of 59000 was obtained.

Synthesis Example 1 for Comparative Example Dimethallyl polyether

[Chemical 19] 137 g, dihydropolydimethylsiloxane

[Chemical 20] 163 g, toluene 350 g, and platinum content 20 p
When the same operation as in Synthesis Example 1 is performed using a platinum-based addition catalyst so as to give pm, the following formula:

[Chemical 21] As a result, 280 g of a linear polysiloxane-polyoxyalkylene block copolymer having a molecular weight of 47,000 was obtained.

Synthesis Example 2 for Comparative Example Dimethallyl polyether

[Chemical formula 22] 200 g, dihydropolydimethylsiloxane

[Chemical formula 23] 126g, 350g toluene, and platinum content 20p
When the same operation as in Synthesis Example 1 is performed using a platinum-based addition catalyst so as to give pm, the following formula:

[Chemical formula 24] As a result, 309 g of a linear polysiloxane-polyoxyalkylene block copolymer having a molecular weight of 87,000 was obtained.

Synthetic Example 3 for Comparative Example Dimethallyl Polyether

[Chemical 25] 100 g, dihydropolydimethylsiloxane

[Chemical formula 26] 43 g, 350 g of toluene, and platinum content of 20 pp
When the same operation as in Synthesis Example 1 is performed using a platinum addition catalyst so that m becomes, the following formula:

[Chemical 27] Thus, 134 g of a linear polysiloxane-polyoxyalkylene block copolymer having a molecular weight of 27,000 was obtained.

Examples 1 to 5 and Comparative Examples 1 to 3 Semi-rigid urethane foam tests were conducted using the surfactants obtained in Synthesis Examples 1 to 5 and Comparative Examples 1 to 3. The results are shown in Table 1 below.

[Table 1] As is clear from Table 1, the present invention is stable in the foam state and has no occurrence of cracks, and is thus excellent as a method for producing a urethane foam.

Examples 6 to 10 and Comparative Examples 4 to 6 Flexible urethane foam tests were conducted using the surfactants obtained in Synthesis Examples 1 to 5 and Comparative Synthesis Examples 1 to 3. The results are shown in Table 2 below.

[Table 2] As is apparent from Table-2, the present invention is excellent in foaming power and holding power for fine bubbles, has a stable foam state, does not cause shrinkage, has no fluctuation in the bubble stabilizing effect, and produces urethane foam. It turns out that it is an excellent method.

[0025]

EFFECT OF THE INVENTION A method for producing a urethane foam, which comprises using the surfactant having a specific chemical structure of the present invention as a foam stabilizer for urethane foam, is excellent in foaming power and holding power for fine foam. The state is stable, there is no shrinkage, cracks, etc., and there is no variation in the bubble stabilizing effect, which is superior to conventional products.

Claims (1)

[Claims] 1. A general formula: (In the formula, R represents a monovalent hydrocarbon group containing no aliphatic unsaturation, n is an integer of 2 to 4, a is an integer of at least 6, b is an integer of at least 4, c is an integer of at least 2, Y represents a divalent organic group bonded to an adjacent silicon atom by a carbon-silicon bond and to a polyoxyalkylene block by an oxygen atom,
The average molecular weight of each siloxane block is about 400 to 1
The average molecular weight of each polyoxyalkylene is 200 to about 10,000, and the polyoxyalkylene block has an average of about 50 ethylene oxide.
To about 80% by weight, the siloxane block making up about 10 to 95% by weight of the copolymer, the polyoxyalkylene block making up about 90 to 5% by weight of the copolymer, and the block copolymer at least About 1,20
A urethane foam characterized in that a surfactant comprising a non-hydrolyzable linear siloxane-polyoxyalkylene (AB) n block copolymer having an average molecular weight of 0) is used as a foam stabilizer of urethane foam. Manufacturing method.