MXPA99009102A - Rigid polyurethane foam based on polyesters of - Google Patents

Abstract

The present invention is directed to a rigid molded foam produced by reaction of: a) one or more organic polyisocyanates with b) a polyol mixture consisting of 1) 100 parts by weight of a mixture consisting of: 1) from 30 to 80 parts by weight of one or more polyethers having hydroxy functionalities of 2 to 3 and molecular weights of between about 1,000 and about 8,000, the polyethers further characterized by not containing nitrogen atoms and not being filled polyethers, 2) from 10 to 50 parts by weight of one or more adducts of toluenediamine and alkylene oxide, the adduct of which has a molecular weight of about 350 to about 700; 3) of pa to 15 parts by weight of one or more di- or trialkanolamines, totaling the amounts of components 1), 2) and 3) 100 parts, and T from about 0.1 to about 4 parts by weight per 100 parts by weight of component b) of a cell-opening silicone surfactant and (d) from 1 to 7 parts by weight d e) water and e) from 0.1 to 2 parts by weight of at least one " mine " catalyst, where the reaction mixture does not contain auxiliary blowing agents and where the amount of polyisocyanate is such that the isocyanate index is 95 to 1.

Description

RIGID POLYURETHANE FOAM BASED ON POLYETERES PE TDA BACKGROUND OF THE INVENTION Energy-absorbing foams based on urethane chemistry are known in the art. The first literature used, in general, halocarbon blowing agents (see, for example, US Patent 3,926,866). A significant number of patents have been granted related to water-swelled energy-absorbent foams based on polyols ("polyolefins"), prepared by polishing mixtures of styrene / acrylomethyl monomers into polytexes (see US Patents 4,116. 893, 4,190,712, 4,212,954, 4,866,102, 5,216,041 and 5,232,957.) Another patented technology describes the use of relatively high molecular weight garlic crosslinkers (see, for example, US Pat. 4,282,330, 5,143,941 and 5,167,884) or the use of various polyols, such as ethylene oxide adducts of Mannich condensates (US Patent 4,371,629), alkoxylated to-luendiamma (US Pat. No. 4,614,754) or propylene glycol or ethylene diamine derivatives (US Patent 5,187,204) .Other patented technology describes energy absorbing foams blown with water as flexible foam (US Patents 4,981. 880 and 5,489,618), while the systems based on some of the As indicated above, they have been used commercially, we continue to look for systems that produce foams, energy absorbents that have a low cost, that meet a variety of specifications, such as compliance with commercial production processing requirements at the most time. demolition of five (5) minutes. The "demold time" is defined as the time from the start of the introduction of the foamable reagents into the mold until the finished part of the mold is removed. SUMMARY OF THE INVENTION The present invention is directed to a rigid molded foam, produced by reaction of: a) one or more organic polusocyanates with b) a polyol mixture consisting of i) 100 parts by weight of a mixture consisting of: 1) from 30 to 80 parts by weight of one or more pali ethers having iiidroxy functionalities of 2 or 3 and molecular weights of from about 1,000 to about 8,000, the polyethers also being characterized as not containing any nitrogen atom and not being filled polyethers, 2) 10 to 50 parts by weight of one or more additives of toluenediamma and an alkylene oxide, the adduct of which has a molecular weight of about 350 to about 700/3) from 0 to 15 parts by weight of one or more di- or tnalkanolammas, totalizing the amount of the components 1), 2) and 3) 100 parts, and c) from about 0.1 to about 4 parts by weight per 100 parts by weight of component b) of a silicone opener surfactant icona and d) from 1 to 7 parts by weight of water and e) from 0.1 to 2 parts by weight of at least one amine catalyst; where the reaction mixture does not contain auxiliary insufflating agents and where the amount of poly-lissatinate is such that the isocyanate number is from 95 to 120. It is an object of the present invention to develop a new mixture of polyols which allows the production of energy absorbing foams that meet the specification of having not less than a five (5) minute demoulding time. Another object of the present invention is not to require the use of expensive filled polyols, still allowing the production of foams that exhibit very low molding pons with good moldability.

DETAILED DESCRIPTION OF THE INVENTION The foams of the present invention are rigid molded foams energy absorbing and water blown, largely produced by reaction of a specified reaction mixture to isocyanates with a polymethylene glycol (phenyl isocyanate). The isocyanate-reactive mixture A) consists of the following specific components; 1) at least one polyether polyol having a hydroxyl functionality of 2 to 3 and a molecular weight varying between 1,000 and 8,000, the polyether being further characterized as not containing nitrogen atoms and not being filled polyethers; 2) one or more adducts of toluenediamma and an alkylene oxide, whose adduct has a molecular weight of 350 to about 700 and, 3) one or more di- or trialkanolanes; B) a cell-opening surfactant, and C) water in an amount ranging from about 1 to about 7 weight percent. The polyether polyols used in component A) and their manufacturing methods are generally known in the art. Examples of some polyethers suitable for use according to the invention are known and can be obtained, for example, by polymerizing tetrahydrofuran or epidoxides, such as, for example, ethylene oxide, propylene oxide, butylene oxide, oxide of styrene or epichlorohydrin, in the presence of suitable catalysts, such as, for example, BF¿ or KÓH, or by chemically adding these epoxides, preferably ethylene oxide and propylene oxide, in admixture or successively, to components containing reactive hydrogen atoms , such as water, alcohols or amines. Examples of suitable alcohols and amines include the low molecular weight chain extenders indicated below, propylene glycol, glycerin, ethylene glycol, triethanolamine, water, tp ethylolpropane, bisphenol A, sucrose, aniline, ammonia, ethanolamine and ethylenediamine. Mixtures of these initiators are also used to prepare polyethers with the desired functionality of 2 to 3 for component A) 1) of the present invention. It is preferred to use polyethers containing substantial amounts of primary hydroxyl groups in terminal positions (more than 80% by weight, based on all terminal hydroxyl groups present in the polyether). Polyether polyols consisting of copolymers of propylene oxide and ethylene oxide are preferably used as component A) l) in the invention. Suitable amine-initiated co or polyether polyols include toluenediamma adducts. These pore initiator polaols and methods for their production are known and described, for example, in US Pat. 4,877,879 and 5,786,405 and in Japanese Abstracts 57168917A and 5716918. These palladium polyethers show promising results in blown foam systems without CFC insufflating agents. Said polyether polyols can be formed by reaction of an amine, such as, for example, toluenediamine, with an alkylene oxide, such as, for example, ethylene oxide or propylene oxide. This reaction can also be catalyzed with an alkaline catalyst, such as potassium hydroxide. Suitable N-substituted ethanolamine and ethanolamine derivatives for use as component A) 3) according to the invention include, for example, ethanolamm, N-methylethanolamm, diethanolamine and triethanolamm. Preferred ethanolamine derivatives include, for example, diethanolamine and triethanolamine. The methods of manufacturing these derivatives are generally known in the art. Polyethylene poly (phenyl isocyanates) useful herein are known in the art and are produced by the reaction of phosgene with aniline / formaldehyde condensates. Known processes for the preparation of the aniline / formaldehyde condensates and the resultant polusocyanates are described in the literature and in many patents, for example US Pat. 2,683,730, 2,950,263, 3,012,008, 3,344,162 and 3,362,979. The isocyanates useful herein contain from about 40 to about 85% by weight of methylene bis (phenyl isocyanate) and have an isocyanate group content of from about 20 to about 35% by weight, preferably from about 30 to about 35S by weight and, more preferably, from about 31 to about 33% by weight. As indicated above, the isocyanate index of the total system is from about 95 to about 120. When water is used as the sole blowing agent, it is typically used in the present invention in amounts of between about 1 and approximately 7. percent by weight and, preferably, between 2 and about 5, 5 weight percent based on 100% by weight of the mixture reactive to isocyanates. Si-1-one cell-surfactant surfactants, which are used in amounts of about 0.1 to about 4 percent by weight, are known in the art. In a preferred embodiment, the silicone cell opener surfactants are used in an amount of about 0.3 to about 2.5 weight percent. Siloxane polyethers are particularly suitable silicone cell opener surfactants. These compounds are generally copolymers having a polydimethylsiloxane group attached to polyethylene oxide and polypropylene oxide chains, or mixed blocks of the two. Examples of useful cell-opening silicone surfactants include those sold as L3802 and L3801, formerly called UAX 6164 and 6137, respectively, marketed by itco. Other examples of useful cell opener silicone surfactants include L3803 from Witco and also the cell-opening sllicone surfactants described in US Pat. No. 5,489,618. The surfactants used in the present invention are superior in molecular weight to the commercially available standard surfactants, which have a molecular weight ranging from about 15,000 to about 90,000. The reaction mixture also contains at least one tertiary amine catalyst to catalyze the reaction between isocyanate groups and hydroxyl groups. The tertiary amine is present in an amount ranging from about 0.05 to about 2 percent by weight and, preferably, between 0.1 and 1 percent by weight. Urethane catalysts are generally known and include tertiary amines, such as triethylamine, tributhylamine, N-methylmorpholma, N-ethylmorpholma, N-cocomorpholma, N, N, N ', N "-tetramet-1-ethylenediamine, 1, 4- diazab? cicls (2, 2, 2) octane, N-methyl-N'-d? met? laminoethyl? ipera2ina, N, N-dimethylbenc? lamma, bis- (N, N-diethylammoethyl) adipate, N, Nd? et? lbenc? lam? na, pen-tamethyldietilentpamine, N, N-dimet? lc? clohexylamine, N, N, N ', N'-tetramethyl-l, 3-butanediamine, N, N-dimethyl-β-fe- Ilethylamine, 1,2-dimethyl-midazole, 2-methylimido2 and the like Commercial tertiary amines, such as Niax AI and Niax AI07, from Witco, are also useful.; Thancat DD, from Hunt = man, and the like. Mannich bases, known per se, obtained from secondary amines, such as dimethylamine, and aldehydes, preferably formaldehyde, and ketones, such as acetone, methyl ethyl ketone or cyclohexanone, and phenols, such as phenol, nonylphenol or bisphenol, can also be used as catalysts. . Silamines with carbon-silicon bonds can also be used as catalysts as described, for example, in German Patent No. 1,229,290 and in US Pat. No. 3,620,984. Also, delayed action catalysts can be used, such as the acid blocked tertiary amines marketed as NIAX A-300, NIAX-400, NIAX-107, DABCO 8154, DABCO DC-1 and DABCO DC-2. Formic acid, 2-ethylhexanoic acid and glycolic acid are typical of the carboxylic acids used to block these amines. other suitable catalysts may include, for example, organometallic catalysts. Examples of suitable organometallic catalysts include, for example, organometallic compounds of tin, lead, iron, bismuth, mercury, etc. Preferred organotin catalysts include compounds such as, for example, tin acetate, tin octoate, tin ethylhexanose, tin oleate, tin laurate, dimethyltin dilaurate, dibutyltin oxide, dibutyltin dichloride, dimethyltin dichloride, dibutyltin diacetate, diethyltin diacetate, di ethyltin diacetate, dibutyltin dilaurate, diethyltin dilaurate, dimethyltin dilaurate, dibutyl maleate, dimethyltin maleate, dioctyltin diodetate, dioctyltin dilaurate, oxy -do di (2-ethylhexyl) tin, etc. Especially preferred are heat-activated or delayed-action tin catalysts, such as, for example, dibutyltin diisooctyl-mercaptoacetate, di-ethyltin dimercaptide, dibutyltin dilaurylmercaptide, dimethyltin dilaptyl mercaptide, dimethyltin dusooctylmercaptoacetate, bis (isooctyl ercaptoacetate) di (n-butyl) tin and di (isooctyl) tin bis (i = ooctyl ercaptoacetate), all marketed by Witco Chemical Corp. The use of a retarded-action catalyst, such as an iron pentanedione or a bismuth carboxylate, as described in US Pat. 4,611,044, here incorporated as a reference, is also possible. The reaction mixture may also optionally contain additives, such as trimerization catalysts. Timerization catalysts (i.e., catalysts that promote the self-polypeptization reaction of isocyanate groups) are known in the art. Finally, according to the present invention, the components can react with each other by known methods, often using mechanical devices, such as those described in US Pat. No. 2,764,565 The details concerning the processing apparatus that can be used according to the invention can be found in Kunststoff-Handbuch, Volume Vn, published by Vie eg and Hochtlen, Carl-Hanser-Verlag, Munich, 1966, pages 121 and 205. The foaming reaction to produce foam products is carried out in molds.In this process, the foamable reaction mixture is introduced into a mold, which may be made of a metal, such as aluminum, or A plastic material, such as an epoxy resin, The reaction mixture forms foam inside the mold, to produce the shape-end product The forming process is foam in molds is carried out to produce a product having a non-cellular structure (skin) on its surface Frequently, so-called external mold release agents known in the art, such as silicone waxes and oils, are used when foaming is carried out within the body. and molds. The procedure can also be carried out with the help of the so-called internal mold release agents., if desired, in combination with external mold release agents, for example as described in German Patent Application Publication Nos. 2,121,670 and 2,307,589. The invention is further illustrated, but without intending to limit it, by the following examples, wherein all parts and percentages are by weight, unless otherwise indicated. EXAMPLES In the following examples, the following materials were used: A) POLYOL A: A poly (oxyalkylene) polyol having a molecular weight of about 4,000 and a functionality of about 2 and which is prepared by adding a mixture of about 87% of propylene oxide and 13% of ethylene oxide to propylene glycol, so that approximately 75% of the hydroxyl groups are primary. B] POLYOL B: A poly (oxyalkylene) polyol having a molecular weight of about 4,800 and a functionality of about 3 and which is prepared by adding a mixture of about 83% propylene oxide and 17% ethylene oxide to glycerm, so that approximately 85% of the hydroxyl groups are primary. C) POLYOL C: A polyether based on ortho-TDA containing units of both ethylene oxide and propylene oxide, which has a hydroxyl number of 395. D) POLYOL D: A polyol PHD based on POLYOL B, with a solids content of 20% and hydroxyl number of 28. £) POLYOL E: A propylene oxide polyether polyol initiated with ethylendia ma, having an average hydroxyl functionality of 4 and a hydroxyl number of 630. F; TEOA: Tpetanolamma (an adduct of ammonia and 3 moles of ethylene oxide). G) DEOA: Dietanolamma (adduct of ammonia and 2 moles of ethylene oxide). H) Dabco DC-l: A catalyst trietilendiamma (TEDA) blocked with acid from Air Products. I) Glycerin. J) Dytec A: An amine (2- methylpentamethylenediamine from DuPont K) B4690: A surfactant from = ilicone from Goldsch idt. L) UAX 6137: a silicone surfactant cell opener marketed by Witco (also known as L3801). M) ÜAX 6164: A silicone surfactant cell opener marketed by Witco (also known as L3802). N) DC-5244: A cell-opening silicone surfactant marketed by Air Products.

Oj NIAX Al: A tertiary amine catalyst (70% solution of bis (dimethylammoethyl) ether) from Witco. P) WATER. Q) ISO: A polymethylenepoly (phenyl isocyanate) containing about 45% by weight of diisocyanate, having an isocyanate group content of about 31.5%, an equivalent weight of about 133 and a viscosity of about 200 mPa-s at 25 * C, marketed by Bayer Corporation. A foam machine, used to make the foamed blocks, was equipped with two REXROTH 12 axial piston pumps and a HennecJe mQ-8 mixing head. The parts were made in an effervescent process in a heated aluminum mold of 10"xl0" x2, 5".The injection pressure was 150 bar on the polyol side and the isocyanate. The flow rate was maintained in the mixing head a 100 g / sec The mixture of polyols was made in the indicated proportions and put in the RIM machine and heated, together with the isocyanate, to a temperature of between 29'C and 32 ° C.

TABLE 1 -FORMULATIONS RASTRA IMPACT Cylindrical head (6") 43 lb. MAZA 17 MPH TABLE 2 £ 1 Example A, which is the same as Example 1, is the control and is beyond the scope of our patent. It is based on a more expensive filled polyether and a crosslinker based on the most expensive initiator, ethylenediamine (compared to ortho-TDA). Note that the molded foam blocks are slightly post-expanded. Examples C and D, based on DC-5244, a conventional cell-surfactant surfactant, are also outside the scope of the patent. Example C, which is based solely on DC-5244, does not show post-expansion, but produces instabilities and is very coarse cells. In Example D, a known cell stabilizer, DC-5043, is added to DC-5244. This time, fine cells are produced, but post-expansion is observed. Example B of the present invention, based on the very high molecular weight silicone, is of fine cells and is formed without post-expansion. Examples 3, 5 and 6 are illustrative of our claims. The open cell content of these three foams is very high. The others, based on B-4690, known as very weak stabilizer, have open cell contents at about 50% and show a slight post-expansion. Although the invention has been described in detail in the foregoing for illustrative purposes, it is to be understood that said detail has only those purposes and that those skilled in the art can make variations therein without departing from the spirit and scope of the invention, except in what may be limited by the claims.

Claims (12)

1. CLAIMS 1. A rigid molded foam produced by reaction of; a) one or more polusocyanate = organic with b) a mixture of polyols consisting of: i) 1Q0 parts by weight of a mixture with: 1) from 30 to 80 parts by weight of one or more polyethers having functional- 2 or 3 nidroxyl dades and molecular weights of about 1,000 to about 8,000, whose polyethers are further characterized as not containing nitrogen atoms and not being filled polyethers; 2) from 10 to 50 parts by weight of one or more adducts of toluenediamma and an alkylene oxide, which adduct has a molecular weight of about 350 to about 700; 3) from 0 to 15 parts by weight of one or more di- or tnalkanolammas, totaling the amounts of 1), 2) and 3) 100 parts, and c) from about 0.1 to about 4 parts by weight per 100 parts in weight of component b) of a silicone surfactant cell opener; d) from 1 to 7 parts by weight of water; e) from 0.1 to 2 parts by weight of at least one tertiary amine catalyst; wherein the reaction mixture does not contain auxiliary blowing agents and where the amount of polusocyanate is such that the isocyanate index is from 95 to 120.
2. 2. A rigid foam molded according to Claim 1, wherein said methylene poly (socianate of fe -nyl) contains from about 40 to about 85% by weight of methylene bis (femlo isocyanate) and has an isocyanate group content of about 20 to about 35% by weight, with the amount of said isocyanate B) that the isocyanate number of the mixture of all isocyanate-reactive components and said isocyanate is from about 95 to about 120.
3. 3. The foam according to Claim 1, wherein said amine is selected from the group consisting of in ethanolane, N-methylethanolamine, diethanolam and triethanolamine.
4. 4. The foam of Claim 3, wherein said amine is triethanolamine.
5. 5. The foam of Claim 1, wherein the isocyanate group content of said polusocyanate is from about 30 to about 35% by weight.
6. 6. The foam of Claim 5, wherein said isocyanate group content of said polusocyte is from about 31 to about 33% by weight.
7. 7. The foam of Claim 1, wherein said water ranges from about 2 to about 5.5% by weight.
8. 8. The foam of Claim 1, wherein said cell-opening silicone surfactant is from about 0.3 to about 2.5 parts by weight per 100 parts by weight of said polyol mixture.
9. 9. The foam of Claim 8, wherein said cell-opening synthetic surfactant consists of a polyene = lloxane.
10. 10. The foam of Claim 9, wherein said cell-opening silicone surfactant has a molecular weight ranging between 15,000 and 90,000.
11. 11. The foam of Claim 1, wherein said foam contains at least one tipping catalyst, ranging from about 3 to about 10 parts by weight of said polyol mixture.
12. 12. The mixture of Claim 1, wherein said tertiary amine catalyst varies between about 0.1 and about 1 part by weight of said mixture of polyols.