MXPA99010546A - Polyurethane foams - Google Patents

Abstract

The present invention relates to a polyurethane foam composition derived from a reaction mixture comprising:a hydrogenated polydiene diol having a number average molecular weight from 1,000 to 20,000;an aromatic polyisocyanate;a plasticiser;and a blowing agent. Preferably, the polyurethane composition further comprises a tackifying resin. The present invention further relates to a process for preparing the polyurethane foam and to articles containing the polyurethane foam.

Description

FOAMS D? POLYURETHANE BACKGROUND OF THE INVENTION: This invention relates to polyurethane foams, in particular flexible polyurethane foams, which contain a polyol and aromatic isocyanates. The invention also relates to a process for preparing polyurethane foams and articles containing polyurethane foams. Polyurethane foams having high resilience are typically produced from a polyether triol and an isocyanate. The polyether triols typically have an average molecular weight number of 4,500 to 6,000 and an average functionality of 2.4 to 2.7 hydroxyl groups per molecule. Toluene diisocyanate, diphenyl diisocyanate methane, mixtures of toluene diisocyanate / diphenyl diisocyanate methane, and modified versions of toluene diisocyanate or diphenyl diisocyanate methane diisocyanate are used to produce foams with ample processing freedom. The functionality of the isocyanate is typically 2.0, and in most cases no higher than 2.3 isocyanate groups per molecule. Polyether triols form resilient foams when combined with isocyanates having from 2.0 to 2.3 isocyanate groups per molecule under conditions that promote foam formation. REF .: 31903 U.S. Patent No. 4,939,184 describes the production of polyurethane foams from polyisobutylene triols and diols, which were prepared cationically. The polyisobutylenes are premixed with an isocyanate, ie an isocyanate which is a mixture of meta- and para-toluene diisocyanate isomers having a functionality of 2.0. Then water was added as a gas injection agent to form the polyurethane foam. The foams obtained were of low resilience and were useful in energy absorption applications. The international application (PCT) WO 97/00902 discloses a high resilience polyurethane foam produced from a polydiene diol. The resilience of the foam was achieved by adding an aromatic polyisocyanate having a functionality of 2.5 to 3.0 isocyanate groups per molecule to ensure adequate crosslinking. The polydiene diol foams produced showed excellent moisture aging properties in comparison to conventional polyurethane foams. U.S. Patent No. 5,710,192 discloses a high resilience, high tear resistance polyurethane foam produced from a polydiene diol. The resilience of the foam was achieved by selecting an appropriate amount of an aromatic polyisocyanate having a functionality of 1.8 to 2.5 isocyanate groups per molecule to ensure adequate crosslinking. The polydiene diol foams produced showed excellent tear resistance and were almost white in color. In the foams described above, the difficulty was found both in the processability and in the control of cell size and cell distribution. It is desirable to have a highly processable foam with small and uniform cell sizes and distribution, while maintaining adequate resilience properties of the foam. Surprisingly, it has been found that the addition of a plasticizer, e.g. up to 50% p of oil, a polyurethane foam produced from a polydiene diol will result in highly processable foams. Therefore, the present invention relates to a polyurethane foam composition derived from a reaction mixture comprising: a hydrogenated diol polyol having an average molecular weight number from 1,000 to 20,000; an aromatic polyisocyanate; a plasticizer; and a gas injection agent.

The foam has lower viscosity during the manufacturing process and more uniform cell structure compared to foams made without oil. According to a further preferred embodiment, the present invention relates to a polyurethane foam composition derived from a reaction mixture comprising: a hydrogenated polydiene diol having an average molecular weight number from 1,000 to 20,000; an aromatic polyisocyanate; a sticky resin; a plasticizer; and a gas injection agent. The plasticizer is preferably compatible with the hydrogenated polydiene diol. A plasticizer is compatible with the hydrogenated polydiene diol if, after mixing the two components in the preferred weight ratio, the components are not separated into two layers in twelve hours, at room temperature. The plasticizers could typically be selected from those known to those skilled in the art. Preferably, the plasticizer is an oil and / or a hydrogenated mono-ol polydiene having an average molecular weight number of from 500 to 20,000.

Description of the Drawings Figure 1 shows the effect of the oil on the viscosity. Figure 2 shows the effect of the oil on the ity of the foam. Figure 3 shows the effect of water content on the ity of foams such as those of the invention.

According to a preferred embodiment, the present invention is preferably a durable resilient polyurethane foam containing 100 parts by weight (pep) of a hydrogenated polydiene diol having an average molecular weight number of 1,000 to 20,000, more preferably 1,000. to 10,000, more preferably from 3,000 to 6,000, from 20 to 55 pep of an aromatic polyisocyanate, up to 200 pep of a plasticizer, more preferably a hydrocarbon processing oil, and a gas injection agent. In a preferred embodiment, the hydrogenated diol polydiene has a functionality of 1.6 to 2, more preferably 1.8 to 2, hydroxyl groups per molecule, and the polyisocyanate used has a functionality of 2.5 to 3.0 isocyanate groups per molecule. The isocyanate is preferably added in a concentration giving almost an equal number of isocyanate groups and hydroxyl groups. Preferably, the molar ratio of NCO: OH is in the range of 0.9 to 1.2. The polydiene diols used in this invention are typically prepared anionically. Anionic polymerization is well known to those skilled in the art and has been described e.g. in U.S. Patents Nos. 5,376,745, 5,391,663, 5,393,843, 5,405,911 and 5,416,168. The polymerization of the polydiene diols begins with a monolithium initiator containing a protected hydroxyl group or dilithium initiator that polymerizes a conjugated diene monomer at each lithium site. Due to cost advantages, the conjugated diene is typically 1, 3-butadiene or isoprene, although other conjugated dienes will also work well in the invention. When the conjugated diene is 1,3-butadiene and when the resulting polymer will be hydrogenated, the anionic polymerization could be controlled with structure modifiers such as diethyl ether or 1,2-diethoxyethane to obtain the desired 1.4 addition amount. The anionic polymerization is terminated by the addition of a functionalization agent before termination. The functionalization agents used are known to those skilled in the art and are described in U.S. Patents 5,391,637, 5,393,843 and 5,418,296. The preferred functionalizing agent is ethylene oxide. The polydiene diols are preferably hydrogenated to improve the stability, so that at least 90%, preferably at least 95%, of the carbon-carbon double bonds in the diols are saturated. The hydrogenation of these polymers and copolymers could be carried out by means of a variety of well-established processes including hydrogenation in the presence of such catalysts as RANEY® Nickel, noble metals such as platinum, soluble transition metal catalysts and titanium catalysts. , as described in the US Patent 5,039,755.

The hydrogenated polydiene diols provide stable, resilient foams. The polydiene diols preferably have from 1.6 to 2, more preferably from 1.8 to 2 terminal hydroxyl groups per molecule. An average functionality of, for example, 1.8 means that about 80% of the molecules are diols and about 20% of the molecules are mono-ols. Since most of the product molecules have two hydroxyl groups, the product is considered a diol. The polydiene diols of the invention have an average molecular weight number between 1,000 and 20,000, more preferably from 1,000 to 10,000, more preferably from 3,000 to 6,000. Hydrogenated polybutadiene diols are preferred, in particular those having an 1,2 addition between 40% and 60%. Diene microstructures are typically determined by nuclear magnetic resonance (NMR) of 13 C in chloroform. It is desirable for polybutadiene diols to have at least about 40% addition of 1, 2-butadiene because, after hydrogenation, the polymer will be a waxy solid at room temperature if it contains less than about 40% addition of 1,2-butadiene. Preferably, the 1,2-butadiene content is between 40 and 60%. The isoprene polymers typically have at least 80% addition of 1,4-isoprene to reduce the glass transition temperature (Tg) and the viscosity. The polydiene diols used in the invention typically have equivalent hydroxyl weights between about 500 and about 10,000, more preferably between 500 and 5,000, more preferably between 1,500 and 3,000. Thus, for the polydiene diols, the appropriate average molecular weight number will be between 1,000 and 20,000, more preferably between 1,000 and 10,000, more preferably between 3,000 and 6,000. The hydrogenated polydiene diol of the Examples has a weight number average molecular weight of 3300, a functionality of 1.92 and a 1,2-butadiene content of 54%. The polymer was hydrogenated to remove more than 99% of the carbon-carbon double bonds. This polymer is hereinafter referred to as Diol 1. The polydiene mono-ols used are prepared substantially as already described herein for the polydiene diols, except that the polymerization is initiated with a monolithium initiator. The monohydroxylated polydiene polymers typically have an average molecular weight number from 500 to 20,000, more preferably from 2,000 to 8,000. The hydrogenated mono-ol polydiene of the Examples has an average molecular weight number of 3850, a functionality of 0.98 and a 1,2-butadiene content of 48%. The polymer was hydrogenated to remove more than 99% of the carbon-carbon double bonds. This polymer is referred to hereinafter as Mono-ol 1. The numbers of average molecular weights referenced herein are numbers of average molecular weights measured by gel permeation chromatography (CPG) calibrated with polybutadiene standards having known average molecular weight numbers. . The solvent for the CPG analysis is tetrahydrofuran. The isocyanates used in this invention are aromatic polyisocyanates, since they have the desired rapid reactivity to make the foam. Since the saturated polydiene diol has a functionality of about 2 hydroxyl groups per molecule, a polyisocyanate having a functionality of 1.8 to 3.0, preferably 2.5 to 3.0, is typically used to achieve a crosslink density that results in a stable foam , high load resistance and high resilience. Using isocyanates of lower functionality results in less stable foams having lower load bearing capacity and having reduced resilience. The higher isocyanate functionality will result in foam having a very high closed cell content, which will negatively influence the physical properties. One example of a suitable aromatic polyisocyanate is MONDUR® MR (Bayer), a polymeric diphenyl polyisocyanate metan that typically has an isocyanate functionality of 2.7. Also used RUBTNATE® 9225 (ICI Americas), a liquid isocyanate consisting of a mixture of 2,4-diphenyl methane diisocyanate and 4,4-diphenyl methane diisocyanate with a functionality of 2.06; however the addition of oil or mono-ol to a foam made with this polyisocyanate of lower functionality could result in the collapse of the foam, requiring the adjustment of the formulation. The oils useful in the invention are oil-based process oils. The compositions of these oils could be in the range of paraffinic to naphthenic for highly aromatic types. The oils that are available cover a wide range of viscosities, from 10 to 1000 centipoise at 38 ° C (100 ° F).

Preferably, the oils to be used in the form of the invention are paraffinic, naphthenic or paraffinic / naphthenic oils, having a viscosity within the above range. An example of an oil suitable for use in the invention is SHELLFLEX® 371 (Shell Oil Company), a paraffinic / naphthenic process oil having a viscosity of 80-100 centipoise at 38 ° C (100 ° F). Because the polydiene diol is a hydrocarbon it has excellent compatibility with hydrocarbon process oils. In addition, there is no tendency for the oil to be exuded from the foam. The addition of oil to the formulation reduces the viscosity, thus improving processability. Fig. 1 shows how the viscosity of the polydiene diol (Diol 1) mixed with oil (SHELLFLEX 371; SHELLFLEX is a registered trademark) depends on the amount of oil in the mixture. Additions of oil up to 200 parts by weight per hundred parts of polydiene diol resin (phr) will decrease the viscosity by a factor of 10 at any temperature. This reduction in viscosity makes the foams of the present invention easier to process than the previous foams, resulting in a more uniform and smaller cell size. Fig. 2 shows the affectation of the oil concentration (SHELLFLEX 371) in the density of the foam of a polydiene diol (Diol 1) mixed with a polyisocyanate (MONDUR® MR) and water. By increasing the oil content from 0 to 200 phr approximately, the density is tripled. The denser resins have smaller cells and distributions of very uniform cell size. The essential components of the polyurethane foams of this invention are the polydiene diol, the aromatic polyisocyanate, a gas injection agent such as water, and a plasticizer, preferably oil, and / or a mono-ol polydiene. Optionally, and preferably, the polyurethane foam further comprises a sticky resin. The tackifying resins useful in the invention are of relatively low molecular weight, predominantly hydrocarbon polymers characterized mainly by their ring and ball softening points, as determined by the standard method E28 of ASTM. Normally, the resins will have softening points in the range of about 80 ° C to about 120 ° C. In certain cases, however, lower softening point resins or liquid resins could be advantageous, for example to obtain the best glue at low temperatures. A typical pay resin is made by cationic polymerization of a mixture containing 60% piperylene, 10% isoprene, 5% cyclopentadiene, 15% 2-met i 1-2 butene and about 10% dimer, as is indicated in the US Patent No. 3,577,398. A resin of this type is commercially available as WINGTACK® 95 (Goodyear Tire &Rubber Company) and has a softening point of 95 ° C. The resins may also contain some aromatic character introduced by the inclusion of styrene or α-methylstyrene in the mixture during the polymerization of the resins. Other types of adhesion-promoting resins that are useful in the invention include hydrogenated resins, resin esters, polyterpenes, terpenphenol resins and polymerized mixed olefins. To obtain good thermooxidative and color stability, it is preferred to use a saturated resin such as a hydrogenated dicyclopentadiene resin such as ESCOREZ® 5000 series (Exxon Chemical Company), or a hydrogenated polystyrene resin such as the REGALREZ® series (Hercules, Inc.). When a glue resin having a high softening point is used, the resin could increase the viscosity of the mixture which reacts to a point where foaming is not actually carried out. The processability of the foam could be improved by the addition of an oil to reduce the viscosity during foaming. Typical oils useful in the invention include paraffinic / naphthenic rubber process oils, as described above. An example of an oil suitable for use in the invention is SHELLFLEX 371. The compatibility of this oil with the polydiene diol / glue mixture is excellent. Therefore, there is no tendency for the oil to exude from the foam, allowing the oil concentration to be adjusted to give the desired viscosity, foam density and glue properties. The processability of the foam could also be controlled by replacing part of the polydiene diol with a mono-ol polydiene. The viscoelastic properties of the foam can be adapted for specific applications by adjusting the ratio of diol to mono-ol. Adhesive foams containing mono-ol up to 75% by weight of the diol / ono-ol mixture have been found to be suitable.

The weight ratio of hydrogenated / plasticizer polydiene is typically at most 5: 1, preferably at most 4: 1, more. preferably at the most 3: 1, in particular at the most 2: 1. The ratio is typically at least 1: 4, preferably at least 1: 3, more preferably at least 1: 1.5, in particular at least 1: 1. The weight ratio of hydrogenated diol polydiene / sticky resin is typically at most 5: 1, preferably at most 4: 1, more preferably at most 3: 1, particularly at most 2: 1. The ratio is typically at least 1: 4, preferably at least 1: 3, more preferably at least 1: 1.5, in particular at least 1: 1. Typically, catalysts and a surfactant are needed in the preparation of the foams. Surfactants are often added to improve the miscibility of the components, which in turn promote the hydroxyl / isocyanate reaction. In addition, the surface tension of the mixture is reduced, which influences the nucleation of the cell and stabilizes the expansion of the foam, leading to a fine cell structure. Preferably, the surfactant is a silicone oil. An example of a commercially available suitable silicone oil is TEGOS -B8404 (TEGOSTAB is a registered trademark). A preferred silicone surfactant is DABCO® DC-5160. The surfactant, if present, is usually added in an amount of 0.01 to 5 parts by weight per 100 pb of the polydiene diol (0.01-5 phr), preferably 0.01 to 1 phr. In principle, any known catalyst could be used to catalyze one or more foaming reactions in the system. Examples of suitable catalysts are described in European Patent Specification No. 0 358 282 and include amines such as tertiary amines, salts of carboxylic acids and organometallic catalysts. Examples of suitable tertiary amines are triethylene diamine, N-methylmorpholine, N-ethylmorpholine, diethyl ethanolamine, N-co-morpholine, l-methyl-4-d imethyl-ami no-ethylpi pe razine, 3-methoxypropyl idimethylamine, N , N, N '-tri-methylisopropyl propylenediamine, 3-diethylamino propyl-diethylamine, dimethylbenzylamine and dimethylcyclohexylamine. An example of a carboxylic acid salt useful as a catalyst is sodium acetate. Examples of commercially available amine catalysts are DABCO® 33-LV and the DABCO® DC-1 slow-release amine catalyst from Air Products and Chemicals. Suitable organometallic catalysts include stannous octoate, stannous oleate, stannous acetate, stannous laureate, lead octoate, lead naphthenate, nickel naphthenate, cobalt naphthenate and dibutyl tin dichloride. Further examples of organometallic compounds useful as a catalyst in the production of polyurethanes are described in U.S. Patent Specification. No. 2,846,408. The amount in which the catalyst, or mixture of catalysts, is used normally falls in the range of 0.01 to 5.0 pbw, preferably in the range of 0.2 to 2.0 pbp per 100 parts of polydiene diol. A variety of gas injection agents could be used. Suitable gas injection agents include halogenated hydrocarbons, aliphatic alkanes and alicyclic alkanes, as well as water which is often referred to as a chemical gas injection agent. Due to the ozone depletion effect of chlorinated or fully fluorinated alkanes (CFC), the use of this type of gas injection agent is not preferred, although it is possible to use them within the scope of the present invention. Halogenated alkanes in which at least one hydrogen atom has not been replaced by a halogen atom (so-called HCFC) have a lower ozone depletion potential and, therefore, are preferred halogenated hydrocarbons for use in foams inflated physically. A very suitable HCFC type gas injection agent is 1-chloro-1,1-difluoroethane. Even more preferred as gas injection agents are the hydrofluorohydrocarbons which are indicated to have a ozone depletion potential of zero. The use of water as a gas (chemical) injection agent is also well known. Water reacts with isocyanate groups according to the well-known reaction NCO / H20, thus releasing carbon dioxide that causes the injection of gas to occur. Aliphatic and alicyclic alkanes, finally, were developed as alternative gas injection agents to CFCs. Examples of such alkanes. they are n-pentane, isopentane and n-hexane (aliphatic), and cyclopentane and cyclohexane (alicyclic). It will be understood that the above gas injection agents could be used alone or in mixtures of two or more. Of the aforementioned air injection agents, water and cyclopentane have been found to be particularly suitable as a gas injection agent for the purpose of the present invention. The quantities in which the gas injection agents are to be used are those conventionally applied, i.e. in the range of 0.1 to 5 pep per 100 parts of polydiene diol in the case of water and in the range of about 0.1 to 20 pep per 100 parts of polydiene diol in the case of halogenated hydrocarbons, aliphatic alkanes and alicyclic alkanes. Preferably, the gas injection agent is water. The water is preferably added in an amount of 0.5 to 3.5 parts by weight (pep) per 100 parts of polydiene diol. Preferably, distilled or demineralized water is used, since the impurities could affect the reaction of the foam. If desired, flame retardants (fire), fillers and other additives could be added. It belongs to the practice of the average expert in this field to select the appropriate additional compounds that are to be added to the composition to be foamed. Antioxidants and ultraviolet stabilizers could be added to further increase the heat and light stability of the foam. Antioxidants of the phenolic type of obstruction, such as IRGANOX® 1076 (Ciba Geigy), are very suitable for stabilizing these foams. "A combination of an ultraviolet light absorber, such as TINUVIN® 328 (Ciba Geigy), and an obstruction amine light stabilizer, such as TINUVIN® 123 (Ciba Geigy), are preferably used for the best resistance to degradation. The polyurethane foams are preferably prepared by mixing all components except the polyisocyanate.The polydiene diol and, if present, the mono-ol polydiene are preheated (typically at about 80 ° C) to reduce the viscosity before mixing Preferably, the tackifying resin is also pre-heated, typically around 150 ° C. After mixing, the aromatic polyisocyanate is added quickly and stirred briefly before pouring the mixture into a mold to heat the expanded foam.

Therefore, a further aspect of the present invention relates to a process for preparing a polyurethane foam composition comprising (i) mixing a hydrogenated polydiene diol, having an average molecular weight number from 1,000 to 20,000, with a plasticizer, a gas injection agent, and, optionally, a tackifying resin, a surfactant and a catalyst to obtain a mixture; (ii) combining an aromatic polyisocyanate with the mixture to obtain a mixture; and (iii) allowing the foaming combination to obtain the polyurethane foam composition. The polyurethane foam could be subjected to a curing treatment by heating the foam to an elevated temperature, usually between 100 and 160 ° C for a certain period of time, typically in the range of 10 minutes to 96 hours, preferably 30 minutes to 48 hours. hours. Usually, however, the heat generated by the exothermic reaction of polyurethane formation is sufficient to ensure complete curing, and the process is carried out adiabatically.

A preferred embodiment of the present invention is a resilient polyurethane foam comprising 100 parts by weight of a hydrogenated polydiene diol having an average molecular weight number of 3,000 to 6,000 and a functionality of 1.8 to 2.0 hydroxyl groups per molecule of 0.5. to 3.5 parts by weight of water, an aromatic polyisocyanate having a functionality of 2.5 to 3.0 isocyanate groups per molecule at a concentration that will give an almost equal number of isocyanate and hydroxyl groups, from 20 to 200 parts by weight oil, of 0.4 to 0.8 parts by weight of an amine catalyst, from 0.3 to 0.6 parts by weight of a slow-acting amine catalyst, and from 0 to 0.06 parts by weight of a silicone surfactant. The foam shows cell size and upper cell size distribution compared to foams made without oil. A further preferred embodiment of the present invention is a resilient polyurethane foam comprising 100 parts by weight of a hydrogenated polydiene diol having an average molecular weight number of 3,000 to 6,000 and a functionality of 1.8 to 2.0 hydroxyl groups per molecule, of 0.5 to 3.5 parts by weight of water, an aromatic polyisocyanate having a functionality of 2.5 to 3.0 isocyanate groups per molecule at a concentration that will give an almost equal number of isocyanate and hydroxyl groups, from 50 to 150 parts by weight of tackifying resin, from 10 to 100 parts by weight of oil, from 0.4 to 0.8 parts by weight of an amine catalyst, from 0.3 to 0.6 parts by weight of a slow-acting amine catalyst, and from 0 to 0.06 parts by weight of a surfactant of sylicon. Yet another preferred embodiment of the present invention is a resilient polyurethane foam comprising from 25 to 100 parts by weight of a hydrogenated polydiene diol having an average molecular weight number of 3,000 to 6,000 and a functionality of 1.8 to 2.0 hydroxyl groups per molecule, from 75 to 0 parts by weight of a polydiene momo-ol having an average molecular weight number from 2000 to 4000, from 0.5 to 3.5 parts by weight of water, an aromatic polyisocyanate having a functionality of 2.5 to 3.0 groups isocyanate per molecule at a concentration which will give an almost equal number of isocyanate and hydroxyl groups, from 50 to 150 parts by weight of sticky resin, from 0 to 100 parts by weight of oil, from 0.4 to 0.8 parts by weight of a amine catalyst, from 0.3 to 0.6 parts by weight of a slow-acting amine catalyst, and from 0 to 0.06 parts by weight of a silicone surfactant. According to a further aspect, the present invention relates to articles containing the polyurethane foam according to the present invention. The following examples are not intended to limit the present invention to specific embodiments, although each example could support a separate claim that ensures that it is a patentable invention.

Example 1 Eight foams were prepared using polymer, isocyanate (MONDUR® MR), catalyst (DABCO® 33-LV and DABCO® DC-1), surfactant (DABCO® DC-5160), and - water in combinations as shown in Table 1. Samples 2- 7 also contained a hydrocarbon process oil (SHELLFLEX® 371) and are the samples shown by the invention. Sample 1 is a comparative example that does not contain oil. Sample 8 is another comparative example containing oil but using a conventional polyether polyol.

In the typical preparation, the polymer and the oil were preheated to 80 ° C. All components in the formulation except the isocyanate were weighed in a dry container and mixed using a CAFRAMO® stirrer equipped with a regular 5.1 cm (2 pig) spacer impeller. The isocyanate was then added and mixing was continued for about 45 seconds. During this time the dough would begin to froth and was poured into a paper cube. After the foam stabilized and a film formed, the foam was post-hardened in an oven for ten (10) minutes at 110 ° C. The specimens were cut from the block for the measurement of foam density, hardness at 40% compression, resilience and hysteresis.

Density The density was determined by the weight of a block and its dimensions. The results are given in Table 2.

Resilience A 16 mm steel ball (16.3 g) was dropped from a height of 51.6 cm through a clear plastic tube, 38 mm in internal diameter, onto a foam block measuring 10 x 10 x 5 cm. Bounce height was measured and resilience was calculated as 100 x (bounce height / fall height). The results are given in Table 2.

Compression Hardness v Loss of Hysteresis Compression hardness and hysteresis loss were measured on an INSTRON® Model 5565 machine. A foam block measuring 10 x 10 x 5 cm was placed between two parallel plates and compressed 60%, then the load was removed, during four cycles at a crosshead speed of 12.5 cm / min. In the fourth cycle, the force required to compress the foam 40% was recorded, giving a measure of compressive hardness of the foam. The hysteresis loss was calculated as the area under the stress / height curve in the fourth cycle with respect to the first cycle. The results are given in Table 2.

Table 1. Foam formulations Table 2. Foam Properties Samples 1-5 were similar formulations with increasing oil contents of Sample 1 (without oil) to Sample 5 (200 phr of oil). Samples 1-5 contained all 1 phr of water and thus all were foamed at approximately the same volume, each expanded by a factor of about 10. With increasing amounts of oil added to that volume, the densities are seen to increase with the increase of oil content. It can be seen that the addition of 11 phr of oil (Sample 2) essentially had no effect on the properties or qualitative appearance of the foam. The addition of 33 phr of oil (Sample 3) somewhat reduced the cell size distribution with only a small effect on density. Additions of 100 to 200 phr of oil (Samples 4 and 5) resulted in foams with small cell sizes, very uniform distribution, but notably denser (heavier) foams. No tendency of oil exudation of any of these foams was observed.

Samples 5-7 and Figure 3 show the effects of increasing the water content in foams containing 200 phr of oil. The higher water content and the resulting increase in the isocyanate content causes more foam formation, thus reducing the density of the foam. It is believed that a foam containing 200 phr will reach a density of 110 g / 1 at about 4 phr of water, a density equivalent to Sample-1 without oil. However, this high-oil foam is expected to have lower compression hardness and cohesive strength than oil-free foam of the same density.

Sample 8 was a conventional foam based on polyether polyol, to which oil was added. It can be seen that these conventional type foams are not suitable for oil additions. The foam has an oily feel and oozes oil due to the incompatibility of the oil and the polyether polymer. 2 Five foams were prepared using Diol 1 or mixtures of Diol 1 / Mono-ol 1, isocyanate (MONDUR® MR), a sticky resin (WINGTACK 95), catalysts (DABCO® 33-LV and DABCO® DC-1), surfactant ( DABCO® DC-5160), and water in the combinations as shown in Table 3. Two foams contained a hydrocarbon processing oil (SHELLFLEX 371).

In the typical preparation, the diol, mono-ol and oil, if present, were preheated to 80 ° C and the sticky resin was preheated to 150 ° C. Subsequently, the procedure of Example 1 was followed.

The density, resilience and compression hardness and hysteresis loss were measured as in Example 1. The results are given in Table 4.

Table 3. Foam formulations OR) Table 4. Foam Properties Sample 1 is an example of a high resilience foam and is used for comparative purposes. At a density of 109 g / 1, it has a compression hardness of 28 N and has good resilience and low hysteresis loss. However, being free of resin does not have the character of glue or adhesive. Samples 9 and 10 examined the effects of adding sticky resin and oil, and adjusting the water content to give foams of approximately constant density. The results show that, as required for pressure sensitive adhesives, these foams are much easier to compress, have much less resilience and much higher hysteresis loss than Comparative Sample 1. Samples 9 and 10 of foam were sensitive adhesives to the pressure very good; both had good grip by the finger and both adhered well to paper and painted surfaces. Both also could be cleanly removed from a substrate, providing examples of a movable adhesive foam. Samples 11-13 show the effects of using a polydiene diol / polydiene mono-ol mixture without oil. Satisfactory foams were not obtained with samples 11 and 12. However, it is believed that by adjusting the preheating temperatures, by mixing the lists and concentrations of catalysts, satisfactory foams can be made with these two formulations. Sample 13 was a very good foam, very soft and sticky. Sample 13 was an unusual foam in that it showed no immediate rebound in the compression, but when it was left to rest, it completely recovered its initial shape and dimensions. Thus, the compression hardness was zero and the hysteresis loss was almost 100%, due to the short time scale of the test, there was almost no recovery of the foam after the first compression. In the resilience test, the foam simply dissipated the energy of the dropped ball and there was no bounce. While this invention has been described in detail for purposes of illustration, this was not constructed as a limit but as an attempt to cover all changes and modifications within the spirit and scope thereof.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (10)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. A polyurethane foam composition derived from a reaction mixture, characterized in that it comprises: a hydrogenated diol polymer having an average molecular weight number of 1,000 to 20,000 and a functionality of 1.6 to 2 hydroxyl groups per molecule; an aromatic polyisocyanate having a functionality of 1.8 to 3.0 isocyanate groups per molecule; a plasticizer; and a gas injection agent, wherein the plasticizer is an oil and / or a hydrogenated mono-ol polydiene having an average molecular weight number of 500 to 20,000.

2. A polyurethane foam composition according to claim 1, characterized in that the reaction mixture further comprises a sticky resin.

3. A polyurethane foam composition according to claim 1 or 2, characterized in that the amount of polydiene diol to plasticizer is in the range of 5: 1 to 1: 4.

4. A polyurethane foam composition according to claim 2, characterized in that the amount of polydiene diol to sticky resin is in the range of 5: 1 to 1: 4.

5. A polyurethane foam composition of confidentiality with claim 1, characterized in that it is obtained by means of a process comprising the steps of: combining the hydrogenated polydiene diol with the aromatic polyisocyanate, the gas injection agent and the plasticizer; and allowing the combined polydiene diol, aromatic polyisocyanate, gas injection agent and plasticizer to foam to obtain the polyurethane foam composition.

6. A polyurethane foam composition according to claim 5, characterized in that the hydrogenated polydiene diol, the gas injection agent, the plasticizer and other components are mixed before combining the mixture with the aromatic polyisocyanate.

7. A polyurethane foam composition according to claim 5 or 6, characterized in that a surfactant and a catalyst are used in the process.

8. A polyurethane foam composition according to any of claims 5 to 7, characterized in that it also comprises a sticky resin.

9. A process for preparing a polyurethane foam composition, characterized in that it comprises (i) mixing a hydrogenated polydiene diol, having an average molecular weight number of 1,000 to 20,000 and a functionality of 1.6 to 2 hydroxyl groups per molecule with a plasticizer, a gas injection agent, and, optionally, a tackified resin , a surfactant and a catalyst to obtain a mixture; (ii) combining an aromatic polyisocyanate having a functionality of 1.8 to 3.0 isocyanate groups per molecule with the mixture to obtain a combination; and (iii) allowing the foaming combination to obtain the polyurethane foam composition, wherein the plasticizer is an oil and / or a hydrogenated mono-ol polydiene having an average molecular weight number "of from 500 to 20,000.

10. Articles, characterized in that they contain the polyurethane foam composition as claimed in any of claims 1-8.