JP2001181397A - Silicone polyether copolymer useful in manufacturing polyurethane flexible molded foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide polyurethane flexible foam molded products having excellent stability relating to bulk, shear, deaeration, surface, and dimension. SOLUTION: Specific types of silicone polyether copolymers are used as the foam stabilizers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the use of specific silicone polyether copolymers as foam stabilizers.
The present invention relates to the production of a polyurethane flexible foam molded article. The present invention provides a water blown with improved surface quality.
blown) to provide a polyurethane flexible molded foam.

[0002]

2. Description of the Related Art Polyurethane foam production involves weighing a resin and a number of liquid components or isocyanate components prepared as a stream and feeding them into a mixer where they are thoroughly mixed and dispensed. It is. A typical formulation includes two streams consisting of an isocyanate and a resin. The resin stream is a crosslinking agent such as polyol, diethanolamine (DEOA),
A mixture of surfactants, catalysts, water, auxiliary blowing agents and other possible additives.

[0003] Foams exhibiting excellent stability have better isotropic physical properties and can be more easily processed using existing equipment. Above all, it is bulky and deaerated (ven
Molded foams with good t) and shear stability are characterized by having a small, uniform cell structure throughout the interior of the foam. Polyurethane foams having excellent surface stability have a layer of fine cells adjacent to the outer surface of the foam. Typically open-cel
The dimensionally stable foam, which is also led), has a reduced tendency to shrink immediately after removal from the mold. Non-molded flexible foams require excellent bulk and dimensional stability, without which the foam will collapse or densify. By reducing the release of additives in the flexible foam, fogging inside the windshield of an automobile may be reduced.

[0004]

SUMMARY OF THE INVENTION Heretofore, bulk, shear,
Chemical strategies for selecting formulation variables to optimize degassing, surface, and dimensional stability have been very successful for many applications. Key variables include careful choice of surfactants and catalysts. Currently, the foam industry is changing its approach to reducing raw materials and / or processing costs while maintaining foam physical properties. Remedies include reducing the density by using less damp chemicals or injecting liquid carbon dioxide, reducing the amount of relatively expensive graft copolymers, using TDI / MDI blends, and Including introducing an isocyanate-terminated prepolymer. In each of these approaches, there is an increasing attempt to use additives that are not always compatible with the prior art.

[0005] Silicone surfactants used in the production of flexible polyurethane foams are typically polydimethylsiloxanes, organofunctional polydimethylsiloxanes or siloxane polyether copolymers.

[0006] US Patent Publication No. 3,402,192 states that
Disclosed are branched polyoxyalkylene siloxane copolymers useful in the preparation of polyurethane foams.

US Pat. No. 4,031,044 discloses:
Disclosed are siloxaneoxyalkylene copolymer surfactants as cell stabilizers for the production of polyether-based highly elastic flexible foams. The '044 patent
Although a very wide variety of structures are taught, the general type relevant to the present invention can be represented by the following formula: Me ₃ Si (OSiMe ₂ ) _x (OSiMeG) _y OSiMe _{3 In the} formula, G is a group having the formula —D (OR ″) _m ^A , wherein D is a divalent organic bonding group, for example, an alkylene group And R ″ comprises propylene groups and groups selected from ethylene and butylene, the amount of ethylene and butylene being less than 35% by weight of the total (OR ″) groups, and m being from 1 to 15 Has an average value, and A is -OR ', -OOC
And R ′ or —OOCOOR ′, wherein R ′ is a group containing no aliphatic unsaturation selected from a hydrocarbon group and a hydrocarbonoxy group. The average value of x is 0-7
, Y has an average value of 1-5; if x = 0, y = 1-5; if x = 1 or 2, y = 1-
4; when x = 3 or 4, y = 1-3; when x = 5, y = 1-2; and when x = 6 or 7, y
= 1. See Example 7 for specific embodiments.

[0008] US Pat. No. 4,139,503 discloses 100 g of a polyol of specific siloxane component for the production of highly elastic, open-cell polyurethane foams.
Uses of 0.01 to 2 g per are disclosed. This patent only shows examples of polydimethyl silicone.

US Pat. No. 4,347,330 discloses polysiloxane-polyoxyalkylene copolymers, polymethylsiloxanes and polyoxyethylene groups in an amount of at least 80% by weight, based on the weight of the polyether polyol. A highly elastic, open-cell, flexible molded polyurethane foam improved by the introduction of three cell modifiers comprising a polyether polyol cell modifier is disclosed.

US Pat. No. 4,650,955 discloses siloxane polyether copolymer surfactants with mixed hydroxyalkoxy capping for stabilizing molded flexible foams.

US Pat. No. 5,633,292 discloses a method for making a highly elastic polyurethane foam using a surfactant containing an alkyl substituent instead of an alkoxy substituent.

[0012]

SUMMARY OF THE INVENTION The present invention is directed to certain precise classes of silicone polyether copolymers belonging to a specific structural area that provides improved surface quality of flexible polyurethane foams. Including the use of

[0013] The present invention is directed to a process for preparing a polyurethane flexible molded foam using a species of silicone polyether copolymer surfactant belonging to a specific structural range. The method comprises reacting an organic polyisocyanate and a polyol in the presence of a catalyst composition, a blowing agent, a silicone polyether copolymer surfactant, a cell stabilizer, and optionally a cell opening agent. Is included. Suitable silicone polyether copolymers have the formula: Me ₃ Si (OSiMe ₂ ) _x (OSiMeG) _y OSiMe _{3 In the} formula, G is a group having the formula —D (OR ″) _m ^A , wherein D is a divalent organic bonding group; "Is an alkylene group, m has an average value of 1 to 5, and A is
-OR '''group or -OOCR''' group, wherein
R ′ ″ is selected from the group consisting of methyl, ethyl and a combination of methyl and ethyl, x has an average value of 1 to 3, y has an average value of 0.25 to 1, x
The value of / y is from 2.5 to 5, and the value of x + y is 1.
5 to 3.5.

[0014] Polyurethane foam can be obtained by a conventional molded flexible polyurethane foam process or "quasi-prepolymer (quas
i-prepolymer) "can be prepared using a molded flexible polyurethane foam process.

[0015] Another embodiment of the present invention includes a silicone polyether copolymer having the above structure.
The use of these particular silicone polyether copolymers in the production of polyurethane flexible molded foams provides the following advantages. Force-to-destruction
improved surface quality without increasing the value of (-crush) (FTC), which is useful for foam quality because it has better cell structure and dimensional stability.

Cell stabilizers used in preparing flexible molded foams include silicone polyether copolymers having the formula: Me ₃ Si (OSiMe ₂ ) _x (OSiMeG) _y OSiMe _{3 In the} formula, x has an average value from 1 to 3, and y is 0.25
Have an average value from 1 to 1 and the value of x / y is from 2.5 to 5
, Preferably from 2.5 to 3.5, especially 3, and the value of x + y is from 1.5 to 3.5, preferably from 1.5 to 2.5, especially 2. G is the formula -D (O
R "is a group having a) _m ^A, D is a divalent organic linking group, R" is an alkylene group. Divalent organic linking group D
Is exemplified by alkylene groups having from 3 to 5 carbon atoms. It is particularly preferred that D is propylene. R "is an alkylene group and m has an average value of from 1 to 5, preferably from 2 to 3. The alkylene group R" is exemplified by ethylene, propylene, butylene, or a combination thereof; It is particularly preferred that "is propylene. Formula A above represents -OR '"
R ′ ″ is selected from the group consisting of methyl, ethyl or a combination thereof.
Preferably, G is a group having the structure: _{-CH 2 CH 2 CH 2 (OCH} (CH 3) CH 2) 2 OCH 3

[0017] The silicone polyether copolymer surfactant is used in an amount of 0.1 to 100 parts by weight of polyol (pphpp).
It is used in parts by weight from 01 to 0.8, preferably from 0.05 to 0.4.

These silicone polyether copolymer surfactants can be prepared by methods well known to those skilled in the art, for example, as taught in US Pat. No. 4,031,044, optionally but preferably , Other silicone surfactants well known for the production of polyurethane foams,
For example, in combination with polydimethylsiloxanes and organofunctional polydimethylsiloxanes, and other silicone polyether copolymers, further disclosed in silicone cell openers such as U.S. Patent Nos. 5,192,812 and 5,852,065. Used in combination with those taught. When used as such a combination, the silicone foam stabilizer according to the present invention can comprise 5-95% by weight of the total silicone surfactant composition.

The silicone polyether copolymer surfactants according to the present invention are used in the manufacture of polyether and polyester flexible molded polyurethane foams in a manner known in the art. In making polyurethane foams using these silicone surfactants, one or more polyether or polyester polyols react with the polyisocyanate to provide urethane linkages. In the present invention, the polyol composition can contain one or more such polyols.

Specific examples of polyols suitable as components of the polyurethane composition are polyalkylene ethers and polyester polyols. Polyalkylene ether polyols include poly (alkylene oxide) polymers, such as polymers of poly (ethylene oxide) and poly (propylene oxide), and copolymers having terminal hydroxy groups derived from polyhydric compounds including diols and triols; Among others, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol,
Includes dipropylene glycol, pentaerythritol, glycerin, diglycerin, trimethylolpropane, and low molecular weight polyols.

In the practice of the present invention, a single high molecular weight polyether polyol can be used. It is also possible to use mixtures of high molecular weight polyether polyols, for example mixtures of di- and trifunctional substances and / or substances of different molecular weight or different chemical composition.

Useful polyester polyols include those obtained by reacting a dicarboxylic acid with an excess of a diol, such as adipic acid with ethylene glycol or butanediol, or reacting a lactone with an excess of a diol, such as caprolactone with propylene glycol. Includes what is manufactured.

In addition to polyether and polyester polyols, masterbatch or premix compositions often contain a polymer polyol. The polymer polyol is a flexible polyurethane foam,
It is used to increase the resistance of the cells to deformation, ie to increase the load-bearing properties of the cells. Currently, two different types of polymer polyols are used to achieve increased yield. The first type, known as a graft polyol, consists of a triol obtained by graft copolymerizing a vinyl monomer. Styrene and acrylonitrile are commonly selected monomers. The second type, a polyurea-modified polyol, is a polyol containing a polyurea dispersion formed by the reaction of a diamine and TDI.
Because TDI is used in excess, some TDI reacts with both the polyol and the polyurea. This second type of polymer polyol has a variant called PIPA polyol, which is formed by in-situ polymerization of TDI and alkanolamine in the polyol. Depending on the load-bearing requirements, the polymer polyols may have a polyol content of 20
-80% can be contained.

The polyurethane product may be any suitable organic polyisocyanate known in the art, such as hexamethylene diisocyanate, phenylene diisocyanate, toluene diisocyanate (TDI) and 4,
It is prepared using 4'-diphenyl-methane diisocyanate (MDI) or the like. Particularly preferred is the use of 2,4- and 2,6-TDI individually or together as a commercial mixture thereof. Another suitable isocyanate is known as "crude MDI" and is commercially available from PAP
Also known as I, is a mixture of diisocyanates containing about 60% 4,4'-diphenylmethane diisocyanate as well as other isomers or similar higher polyisocyanates. Also suitable are "prepolymers" of these polyisocyanates, comprising a polyisocyanate and a polyether or polyester polyol, which have been partially reacted in advance.

Suitable urethane catalysts useful in the present invention are well known to those skilled in the art and include tertiary amines such as triethylene-diamine, N-methylimidazole, 1,2-
Dimethylimidazole, N-methylmorpholine, N-ethylmorpholine, triethylamine, tributylamine,
Pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, triethanolamine, dimethylethanolamine and bisdimethylaminodiethyl ether, and organotins, such as stannous octoate, stannous acetate, stannous oleate, laurin Stannous acid, dibutyltin dilaurate, and other such tin salts are included.

Other typical agents that can be found in polyurethane foam formulations include chain extenders such as ethylene glycol and butanediol; crosslinkers such as diethanolamine, diisopropanolamine, triethanolamine and tripropanol. Amines; cell openers, such as silicones; and especially blowing agents, such as water, liquid carbon dioxide, acetone, pentane, HFCs, HCF
C, CFCs, methylene chloride and the like.

The preferred polyurethane flexible molded foam prepared according to the present invention is a high modulus foam.

A typical polyurethane flexible molded foam formulation containing a silicone surfactant composition according to the present invention and having a density of 1-3 lb / ft ³ (16-48 kg / m ³ ) (eg, for automotive seats) The filling comprises the following components (parts by weight (pbw)):

(Flexible foam formulation (pbw)) Polyol 20-100 Polymer polyol 80-0 Foam stabilizer 0.01-0.8; preferably 0.05-0.4 Silicone foam opener 0-3 Foaming agent 2-4.5 Crosslinking agent 0.5 -2 Catalyst composition 0.3-2 Isocyanate value 70-115

In the present invention, preferred blowing agents for producing flexible molded foams are from 1 to 6 parts of water (pphpp), especially from 2 to 4.5 parts per hundred parts of polyol.
phpp, optionally used with other foams.

[0031] Other additives can of course also be used and can impart specific properties to the foam. Examples are substances such as, for example, flame retardants, colorants, fillers and hardness modifiers.

The polyurethane foam of the present invention is formed by any of the processing techniques known in the art, for example, the "one-shot" method. According to this method, a foamed product is provided by performing the reaction between the polyisocyanate and the polyol simultaneously with the foaming step. In another embodiment, the molded flexible foam can also be made by a "quasi-prepolymer process" as taught in U.S. Patent Nos. 5,708,045 and 5,650,452. It is. In each case, the reaction mixture
It is convenient to add silicone surfactants (cell openers and cell stabilizers) as a premix with the blowing agent, polyol, water, and one or more of the catalyst components.

It should be understood that the amounts of each of the various components of the foam formulation are not strictly critical. The polyol and polyisocyanate are present in the foam generating formulation in amounts as major components. The relative amounts of these two components in the mixture are well known in the art. Blowing agent, catalyst, and silicone surfactant cell opener and cell stabilizer, respectively, are present in small amounts to foam the reaction mixture. The catalyst is the amount of the catalyst,
That is, the surfactant is present in an amount necessary to catalyze the reaction to produce urethane and urea in an appropriate ratio, and the surfactant imparts desired properties and stabilizes generated bubbles, for example, 0%. It is present in a sufficient amount to go from .01 to 0.8 pphpp.

In a typical preparation, a polyol,
When the water, silicone surfactant, amine catalyst, optional tin catalyst and other blowing agents are mixed together, and finally the TDI is mixed, the composition can foam and polymerize.

The present invention has the following features. The silicone polyether copolymer surfactant has a value of x / y of 2.5 or more and 5 or less, and a value of x + y of 1.5 or more.
When it is 5 or less, unexpectedly excellent surface stabilizing properties are obtained without increasing the force required for breaking the foam. This provides a more open cell with less shrinkage after processing. Normally, improvements in surface stabilization are accompanied by an increase in the force required to break the foam.
A preferred structure is x = 1.5 and y = 0.5,
This is the case where R has the structure of the following formula. _{-CH 2 CH 2 CH 2 (OCH} (CH 3) CH 2) 2 OCH 3

The silicone surfactant can be mixed with a dimethyl silicone fluid, cell opener, other silicone polyether copolymer or diluent to obtain additional utility and optimize performance.

[0037]

EXAMPLES Example 1 The silicone copolyether copolymer surfactant of Table 2 was replaced with a trimethylsiloxy endblocked polydimethylsiloxane-polymethyl having the formula: Me ₃ Si (OSiMe ₂ ) _x (OSiMeH) _y OSiMe ₃ Hydrogen-siloxane copolymers and unsaturated polyethers having the formula: CH ₂ ＣＨCHCH ₂ [OCH (CH ₃ ) CH ₂ ] ₂ OCH ₃ are described in US Pat.
Prepared by reacting in the presence of a hydrosilylation catalyst according to the procedure disclosed in US Pat. No. 31,044.

[0038] A silicone polyether copolymer surfactant was prepared in the following manner. A three-necked round bottom flask was equipped with a reflux condenser, an air power mechanical stirrer, and a thermometer equipped with a temperature monitoring control.
The thermometer well was fitted with a side arm gas intake valve fitted with a controlled nitrogen supply. The above trimethylsiloxy endblocked polydimethylsiloxane-polymethyl-hydrogensiloxane copolymer (the values of x and y are listed in Table 2 below) and the unsaturated polyether in a flask in the amounts shown in Table 1 below. And the environment was inert with nitrogen. The nitrogen through the mixture was maintained in a gradual gas flow by observing nitrogen gas bubbles exiting the top of the reflux condenser via dipropylene glycol. The speed was maintained at about 1 bubble per second. Thereafter, the mixture is stirred and the mixture is
Heated to 5 ° C. Next, a catalyst (0.5 g of chloroplatinic acid / isopropyl alcohol (IPA)) prepared as a 0.1 M solution
The mixture was catalyzed using 31.86 microliters (10 ml). Exothermic peak (140-16)
(0 ° C.) for 1 hour. The resulting product was cooled, stripped by applying a vacuum of 120 mmHg at a temperature of 100 ° C. and held for 1 hour to remove volatile components. The product was cooled and identified by FTIR, GPC, and viscosity. Table 2 shows the resulting silicone polyether.
It describes in.

[Table 1]

The silicone polyether copolymer surfactant of Table 2 has the formula: Me ₃ Si (OSiMe ₂ ) _x (OSiMeG) _y OSiMe _{3 where} G is —CH ₂ CH ₂ CH ₂ (OCH (CH ₃ ) CH ₂ ) ₂ OCH ₃ , where x and y are as defined in Table 2 below.

[0040]

[Table 2] ^* Equivalent to surfactant (3) of Example 7 of U.S. Pat. No. 4,031,044 ^** Equivalent to surfactant (2) of Example 7 of U.S. Pat. No. 4,031,044 ^*** U.S. Pat. No. 4,031,044 Almost equivalent to the surfactant (2) of Example 7

In the following examples, the silicone surfactants in Table 2 were compared with commercially available silicone surfactants typically used in making HR flexible molded foams. In the examples and tables, the following substances were used. Lyonde
ARCOL ^R E656 polyether polyol from LL (OH # = 35), Atlantic Richfield, Co., Los Angels, Cal
ARCO from Lyndell (OH # = 24) manufactured by ifornia 90071
L ^R E 688 SAN Polyol. Air Products and Chemicals,
Inc. (APCI) (Allentown, Pennsylvania 18195), D
ABCO ^R 33LV ^R catalyst. APCI made of DABCO ^R BL-11 catalyst. APCI made of DABCO ^R BL-17 catalyst. APCI made of DABCO ^R DEOA-LF - diethanolamine / water (85/15). APCI POLYCAT ^R 7
7 catalyst. PRC-798 from ChemTrend, a solvent-based release agent.
w SPECFLEX ^R manufactured by Chemical (Midland, Michigan 48674)
NC630, well-known triol; SPECFLEX ^R manufactured by Dow Chemical
NC700 polymer polyol. Bayer TDI 80/20.
Are the HR flexible foam formulations A and B used in the examples.
Is expressed in effective parts by weight (pbw) of the component.

[0042]

[Table 3]

Example 2 Polyols Listed in Formulation B
Are premixed and at 70-73 ° F (21-23 ° C)
Stored in the incubated container. Water, crosslinking agents,
Separate mixtures of amine and amine catalysts were also prepared. Foam
Typically, first, the polyol and the surfactant are halved.
In a gallon (1890 ml) paper cup, 3 inches (7.
Servodyner d with 6 cm) disk-shaped stirring blade
Mix for 20 seconds at 6000 rpm using ispersator
It was generated by: Water-amine blend
Introduced into one paper cup, 6000 revolutions for another 20 seconds
And mixed. Next, add TDI to the paper cup for 5 seconds
Mixed. Finally, the entire contents of the cup are 12 × 12 ×
PRC-79, 4 inches (30 × 30 × 10 cm)
8 Removal of 155 ° F (68 ° C) treated with release agent
Aluminum mold with five pores (five vent alminummold)
For 5 seconds. The mold closed immediately. 330
After a second, remove the foam pad and observe the surface.
Remove it from the mold using a metal plate and crush it by hand.
Was. The force to break (FTC) is 50 inches flat
(323cm ^Two) Absolute pounds using the test plate
(Newton). Then cured foam
Cut body into 1 inch (2.54 cm) pieces, bulky, degassed
And surface stability. Stability and surface measurements
Was evaluated by comparing the foam with an internal standard.
Regarding the characteristic of the displacement, it is preferable that the value is large.

According to the data in Table 4, x greater than 2.5
The / y value is shown to be advantageous.

[Table 4] ^* Silicone surfactant activator

Foams prepared using silicone surfactants D, E, G1, Q and R with high x + y values showed that excellent surface values of 4 or more were achieved, Was accompanied by an unacceptably high FTC value. However, Silicone Surfactant B with an x / y value of 3 resulted in a foam with low FTC and good surface resulting from low x + y values.

Example 3 The procedure of Example 2 was repeated, except that Formulation A was used instead of Formulation B.

[Table 5] ^* Silicone surfactant activator

The polyol used in the foam formulation for this Example 3, as can be seen by comparing the performance of each surfactant in Table 4 against the use concentration of 0.06 pphpp in Table 5 As a result, a significantly lower FTC was obtained. Due to the inherently low stability of Formulation A in this example, depending on the type of polyol, to demonstrate the benefits of Surfactant B over the other surfactants in the table,
Higher surfactant concentrations should be employed. Statistical analysis of the data in this example shows a general trend similar to the previous example (high x / y and low x + y values provide superior bulk and surface stability and low FTC values). However, this tendency is shown in Table 5 when the concentration of the working solution is 0.
Examining the data for the 06pphpp case is not clear. Furthermore, when the surfactant is used at a higher working concentration of 0.4 (see Table 5), the bulk stability and surface quality are even higher and show relatively low FTC values. The other surfactants in Table 5, which have high ratings for both bulk stability and surface quality, have high FTC values.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor David Robert Batis USA 48654 Michigan Pull Denville Pony Trail 103 (72) Inventor John Herbert Frey USA 18106 Pennsylvania Allen Town Field Stone Street 1627

Claims (2)

[Claims] 1. The formula: Me ₃ Si (OSiMe ₂ ) _x (OSiMeG) _y OSiMe ₃ [where x has an average value from 1 to 3 and y is 0.2
Has an average value from 5 to 1, the value of x / y is from 2.5 to 5, the value of x + y is from 1.5 to 3.5, and G is the formula -D (OR ") _m ^A : {wherein D is a divalent organic linking group, R ″ is an alkylene group, m has an average value of 1 to 5, and A is —OR ′ ″ group or —
OOCR ′ ″ group, wherein R ′ ″ is a group having｝ selected from the group consisting of methyl, ethyl or a mixture thereof. 2. The copolymer according to claim 1, wherein G is a group having the following structure: —CH ₂ CH ₂ CH ₂ (OCH (CH ₃ ) CH ₂ ) ₂ OCH ₃ .