TW201538649A - Viscoelastic foam system - Google Patents

Abstract

A viscoelastic foam system comprises a viscoelastic foam and spheres dispersed in the viscoelastic foam. Each sphere comprises a gas-filled spherical particle and a polyurethane coating disposed about the gas-filled spherical particle. The polyurethane coating comprises the reaction product of a prepolymer and a polyol component. The prepolymer comprises the reaction product of an isocyanate component and an isocyanate-reactive component, and the prepolymer comprises from 2.5 to 3.6 % by weight of urethane groups based on 100 % by weight of the prepolymer. The polyurethane coating disposed about the gas-filled spherical particle has a shore OO hardness value of from about 20 to about 50 measured according to ASTM D2240 type OO hardness scale.

Description

Viscoelastic foam system

The present invention generally relates to a viscoelastic foam system. More specifically, the present invention relates to a viscoelastic foam system comprising a viscoelastic foam and a sphere dispersed in the viscoelastic foam.

Viscoelastic foams can be used in a variety of articles such as mattresses, pillows, mats, stuffed animals, and the like. In some cases, the viscoelastic foam is a memory foam that exhibits unique compression and recovery characteristics. As a memory foam, the viscoelastic foam may conform to the shape of a body (for example, a human body) disposed on the viscoelastic foam, for example, in response to heat and/or pressure generated by the body, and then The body returns to its original shape after removal of the viscoelastic foam. However, when the body is placed on the viscoelastic foam, the viscoelastic foam retains heat generated by the body. In some cases, the heat retained by the viscoelastic foam can cause the body to overheat and/or experience some discomfort.

The present invention provides a viscoelastic foam system comprising a viscoelastic foam and a sphere dispersed in the viscoelastic foam. Each sphere comprises inflatable spherical particles and a polyurethane coating disposed adjacent the inflatable spherical particles. The polyurethane coating comprises the reaction product of i) a prepolymer comprising a reaction product of an isocyanate component and an isocyanate-reactive component, the prepolymer comprising 100% by weight of the prepolymer 2.5% to 3.6% by weight of urethane groups; and ii) a polyol component. According to ASTM D2240 type The OO hardness scale measures the Shore OO hardness value of the polyurethane coating from about 20 to about 50.

Viscoelastic foam systems can be used in a variety of applications, such as bedding applications including mattresses, pillows, blankets, and/or the like. Viscoelastic foam systems can also be used, for example, in mats, furniture, toys (eg, stuffed animals), medical devices (eg, medical table mats), and the like. Without being bound by any theory, it is believed that the sphere having the polyurethane coating disposed adjacent to the inflated spherical particles acts as a local heat sink within the viscoelastic foam. As a local heat sink, the spheres actively remove (e.g., absorb) heat from the viscoelastic foam. Because the heat is removed, the sphere imparts a cooling effect to the viscoelastic foam. The cooling effect of the salty sphere will increase the overall comfort of the body (eg, a person) placed on the viscoelastic foam system. In addition, the presence of spheres in the viscoelastic foam improves the flow of air through the matrix of the viscoelastic foam. It is believed that this improved air flow also promotes the cooling effect imparted by the sphere to the viscoelastic foam.

A viscoelastic foam system as disclosed herein generally comprises a sphere dispersed in a viscoelastic foam. As mentioned earlier, the sphere imparts a cooling effect to the viscoelastic foam. Therefore, the term "sphere/s" may be referred to as "cooling sphere/s".

The spheres of the viscoelastic foam system generally comprise gas-filled spherical particles, wherein each of the gas-filled spherical particles has a polyurethane coating disposed adjacent the gas-filled spherical particles. The aerated spherical particles may be selected from hollow spheres, each comprising a shell of encapsulating gas. In one example, the inflated spherical particles each comprise a thermoplastic shell of an encapsulating gas, such as an inert gas. Additionally, the effective particle size of the aerated spherical particles is from about 1 [mu]m to about 100 [mu]m, and more typically from about 30 [mu]m to about 50 [mu]m. The density of the inflated spherical particles is also from about 0.01 gram/cm 3 (g/cc) to about 0.05. g/cc and more typically from about 0.038 g/cc to about 0.046 g/cc. Suitable inflatable spherical particles are available from AkzoNobel N.V. (Amsterdam, the Netherlands) under the trade name EXPANCEL® 551 DE40 d42. EXPANCEL® 551 DE40 d42 spherical particles are lightweight, aerated, thermoplastic, hollow spherical particles with a whitish color. In one example, the EXPANCEL® 551 De 40 d42 spherical particles have a density of from about 0.03 g/cc to about 0.06 g/cc. In another example, the EXPANCEL® 551 De 40 d42 spherical particles have a density of from about 0.038 g/cc to about 0.046 g/cc. In yet another example, the density of the EXPANCEL® 551 De 40 d42 spherical particles is about 0.045 g/cc. When the EXPANCEL® 551 DE40 d42 spherical particles are heated, the thermoplastic shell softens and the pressure of the gas encapsulated by the shell increases. This increase in the pressure of the encapsulated gas causes the spherical particles to expand. When a sphere (which includes inflatable spherical particles) is dispersed in a viscoelastic foam, generally light, hollow spherical particles obtain a better gas flow between adjacent spherical particles.

A polyurethane coating is placed adjacent to the inflated spherical particles to form a sphere. When the polyurethane is placed in the vicinity of the aerated spherical particles, the polyurethane is partially or wholly coated on the aerated spherical particles. Typically, the polyurethane coating is disposed adjacent to the entire surface of each of the inflated spherical particles dispersed in the viscoelastic foam. However, it should be understood that the polyurethane coating may be disposed adjacent to at least a portion of the surface of the inflatable spherical particles dispersed in the viscoelastic foam. In some cases, the polyurethane coating may be disposed adjacent to the entire surface of some of the inflated spherical particles dispersed in the viscoelastic foam, and may be disposed to be dispersed in the viscoelastic foam. The vicinity of the surface of one of the other inflatable spherical particles.

Further, the polyurethane coating is usually disposed in the vicinity of all of the inflated spherical particles dispersed in the viscoelastic foam. However, it should be understood that not all of the inflated spherical particles are required to have a polyurethane coating disposed adjacent to the inflated spherical particles. In one example, about 100% of the inflated spherical particles dispersed in the viscoelastic foam have a polyurethane coating disposed adjacent the aerated spherical particles. In another example, at least 95% of the aerated spherical particles dispersed in the viscoelastic foam have a polyurethane coating disposed adjacent to the aerated spherical particles.

The polyurethane coating disposed adjacent to the inflated spherical particles typically comprises the reaction product of a prepolymer and a polyol component.

The prepolymer is the reaction product of an isocyanate component and an isocyanate-reactive component, and may be referred to as an isocyanate-based prepolymer or a heteroprepolymer.

The isocyanate component typically comprises a plurality of isocyanate (NCO) functional groups. In one example, the isocyanate component comprises at least two (2) NCO functional groups, and for this reason, the isocyanate component is said to have a functionality of at least 2. In another example, the isocyanate component can have from 2 to 8 NCO functional groups. In yet another example, the isocyanate component can have from 2 to 6 NCO functional groups. In another example, the isocyanate component can have from 2 to 4 functional groups. In yet another example, the isocyanate component has 2 functional groups, and thus has a functionality of 2.

The isocyanate component can be selected from a plurality of conventional aliphatic, cycloaliphatic, and aromatic isocyanates. In some examples, the isocyanate component is selected from the group consisting of diphenylmethane diisocyanate (MDI), polymeric diphenylmethane diisocyanate (PMDI), and combinations thereof. Polymerized diphenylmethane diisocyanate is also known as polymethylene polyphenyl polyisocyanate. In other examples, the isocyanate component is emulsified MDI (eMDI) or hydrogenated MDI (HMDI). Additional examples of isocyanate components include toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and combination.

In one example, the isocyanate component is selected from the group consisting of isomers of diphenylmethane diisocyanate (MDI). More specifically, the isocyanate component is selected from the group consisting of 2,2'-diphenylmethane diisocyanate (2,2'-MDI) and 2,4'-diphenylmethane diisocyanate (2,4'-MDI). And 4,4'-diphenylmethane diisocyanate (4,4'-MDI). In one example, the isocyanate component is 4,4'-MDI. In other examples, the isocyanate component can be selected from a combination of two or more isomers of MDI. For example, the isocyanate component can comprise a combination of 4,4'-MDI and 2,4'-MDI, wherein the 4,4'-MDI comprises from about 50% to about 98% of the isocyanate component.

For example, the isocyanate-reactive component can comprise a polyol and/or a polyamine having a plurality of functional groups (eg, OH or NH functional groups) that react with the NCO functional groups of the isocyanate component. ). In one example, the isocyanate reactive component is a polyol and/or polyamine having a functionality of at least 2. In another example, the isocyanate reactive component is a polyol having a functionality of from 2 to 8 and/or a polyamine. In another example, the isocyanate reactive component is a polyol having a functionality of from 2 to 6 and/or a polyamine. In yet another example, the isocyanate reactive component is a polyol having a functionality of 2 to 4 and/or a polyamine.

The isocyanate reactive component can comprise any type of polyol. As the polyol, the isocyanate-reactive component may comprise a polyester polyol, a polyether polyol, a polyether/polyester polyol, or a combination thereof. Further, the isocyanate-reactive component may be selected from the group consisting of aliphatic polyols, cycloaliphatic polyols, aromatic polyols, heterocyclic polyols, and combinations thereof. Some examples of suitable isocyanate-reactive components include, but are not limited to, ethylene glycol-initiated polyols, glycerol-initiated polyols, sucrose-initiated polyols, sucrose/glycerol-initiated polyols, trishydroxyl Methylpropane starting polyols and combinations thereof.

Suitable polyether polyols include, for example, ethylene oxide (EO), propylene oxide (PO), butylene oxide (BO), and tetrahydrofuran in the presence of a polyfunctional initiator. A product obtained by polymerization of a cyclic oxide. Suitable initiator compounds contain a plurality of active hydrogen atoms and include, but are not limited to, water, butylene glycol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, ethanolamine, diethanolamine, three Ethanolamine, toluene diamine, diethyltoluenediamine, phenyldiamine, diphenylmethanediamine, ethylenediamine, cyclohexanediamine, cyclohexanedimethanol, resorcinol, bisphenol A, Glycerin, trimethylolpropane, 1,2,6-hexanetriol, isovalerol, and combinations thereof.

Other suitable polyether polyols include polyether diols and triols, such as by simultaneous or A polyoxypropylene diol and a triol and a poly(oxyethylene-oxypropylene) diol and a triol obtained by continuously adding ethylene and propylene oxide to a difunctional or trifunctional initiator. It is also possible to use a copolymer having an oxyethylene content of from about 5% by weight to about 95% by weight based on the total weight of the polyol component and a copolymer having an oxypropylene content of from about 5% by weight to about 100% by weight. These copolymers can be block copolymers, random/block copolymers or random copolymers. Other suitable polyether polyols include polybutadiene diols obtained by the polymerization of tetrahydrofuran.

In one example, the isocyanate reactive component is a blocked polyether polyol. As used herein, the term "capped" means that one or more ends of the polyether polyol are occupied by, for example, an alkylene oxide group. In one example, the polyether polyol is capped with ethylene oxide. In other examples, the polyether polyol is capped with ethylene oxide, propylene oxide, butylene oxide, or a combination thereof.

In one example, the isocyanate reactive component is a polyether polyol having a _{Mw of} from about 3,000 to about 6,000. In yet another example, the isocyanate reactive component is a polyether polyol having a _{Mw of} from about 4,000 to about 6,000. In another example, the isocyanate reactive component is a polyether polyol having a _{Mw of} from about 4,800 to about 5,000.

Suitable polyester polyols include the hydroxyl terminated reaction product of a polyol, a polyester polyol obtained by polymerization of a lactone such as caprolactone together with a polyol, and a polymerization of a hydroxycarboxylic acid such as hydroxycaproic acid. Polyester polyol. Polyester phthalamide polyols, polythioether polyols, polyester polyols, polycarbonate polyols, polyacetal polyols, and polyolefin polyols can also be used.

In certain instances, the isocyanate reactive component of the system comprises a natural oil polyol (NOP), also known as a biopolyol. In other words, the polyol is not a petroleum-based polyol (ie, a polyol derived from petroleum products and/or petroleum by-products). In general, there are several naturally occurring vegetable oils containing unreacted OH functional groups, and castor oil is generally commercially available and is produced directly from a plant source having a sufficient OH functional group content to render the castor oil suitable for the amine. The carbamate chemical reaction is directly used as a polyol. If not all, most other NOPs require the chemicalization of oil obtained directly from plants. Learn to change quality. NOP is usually derived from any natural oil, such as from vegetable oils or nut oils. Examples of suitable natural oils include castor oil and NOP derived from soybean oil, rapeseed oil, coconut oil, peanut oil, rapeseed oil and the like. The use of these natural oils can be applied to reduce the environmental footprint.

In some examples, the isocyanate reactive component comprises a graft polyol. In one example, the graft polyol is a polymer polyol. In other examples, the graft polyol is selected from the group consisting of polyurea (offset PHD) polyols, polyisocyanate polyaddition (PIPA) polyols, and combinations thereof. The graft polyol can also be referred to as a graft-dispersed polyol or a graft polymer polyol. In one example, the isocyanate reactive component comprises a styrene-acrylonitrile graft polyol.

In another example, the isocyanate reactive component can be a polyamine comprising one or more amine (NH) functional groups. In this case, the isocyanate-reactive component typically comprises at least two amine groups. The polyamine can be selected from any type of polyamine. Some examples of suitable polyamines include ethylenediamine, toluenediamine, diaminodiphenylmethane, polymethylene polyphenyl polyamine, amine alcohol, and combinations thereof. Examples of the amino alcohol include ethanolamine, diethanolamine, triethanolamine, and a combination thereof.

It will be appreciated that the isocyanate reactive component can include any combination of the foregoing polyols and/or polyamines.

As mentioned previously, the prepolymer comprises the reaction product of an isocyanate component and an isocyanate-reactive component. In order to form the prepolymer, the isocyanate component is reacted with a sufficient isocyanate-reactive component such that the prepolymer has from 2.5 wt% to 3.6% by weight of the urethane, based on 100% by weight of the total prepolymer (also That is, the NC=O) group. In another example, to form the prepolymer, the isocyanate component is reacted with sufficient isocyanate reactive component such that the prepolymer has from 3.2% to 3.6 weight percent amine based on 100% by weight of the total prepolymer. Carbamate group. Thus, the prepolymer comprises residual isocyanate groups which can be used in subsequent reactions between the prepolymer and the polyol component to form a polyamine based acid ester coating disposed adjacent to the aerated spherical particles. .

Without being bound by any theory, the salty polyurethane gel can be formed by the reaction between a polyol component and a prepolymer having a prepolymer of 100% by weight. 5% by weight to 3.6 % by weight of urethane groups. Further, when the amount of the urethane group in the prepolymer is less than 2.5% by weight based on 100% by weight of the prepolymer or when the amount of the urethane group in the prepolymer is When the polymer is more than 3.6% by weight based on 100% by weight, the polyurethane gel cannot be formed. For example, when the amount of the urethane group is less than 2.5% by weight, all of the urethane groups will be consumed during the subsequent reaction between the prepolymer and the polyol component. While polyurethanes will be formed, most polyurethanes (eg, greater than 3.6% by weight of the polyurethane) will not be characterized by a polyurethane gel. In addition, when the amount of the urethane group is more than 3.6% by weight, a soft polyurethane coating is formed (that is, the Shore OO hardness value of the polyurethane coating is greater than 50). Instead of a polyurethane gel.

In one example, the reaction between the isocyanate component and the isocyanate-reactive component is accelerated in the presence of a catalyst to form a prepolymer. For example, the catalyst can be selected from an organic base such as a tertiary amine or an organometallic compound.

Prepolymers may also be formed in the presence of one or more other additives such as crosslinking agents, chain extenders (eg, low molecular weight polyfunctional aliphatic or aromatic alcohols or amines), colorants, and fillers (eg, Organic and inorganic fillers). The additive can be combined with the isocyanate component and/or the isocyanate reactive component prior to reacting the isocyanate component with the isocyanate reactive component. Alternatively, the additive may be introduced as a separate component after the isocyanate component has been combined with the isocyanate reactive component.

Examples of chain extenders generally have a backbone having from 2 to 8 carbon atoms. In another example, the chain extender has a backbone having from 2 to 6 carbon atoms. The weight average molecular weight (M _w ) of the chain extender is also, for example, less than 1,000. In another example, the chain extender has a _{Mw of} from 25 to 250, and more typically, _Mw is less than 100.

The chain extender can have two isocyanate reactive groups. In one example, the chain extender is a diol having a hydroxyl group as an isocyanate reactive group. The chain extender may be selected from the group _consisting of 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-butanediol, 1,3-propanediol, _{Mw of} up to 200 , 5-pentanediol, ethylene glycol, diethylene glycol and polyethylene glycol. Suitable examples of commercially available chain extenders are NIAX® DP-1022 from Crompton OSi Specialties (Greenwich, CT) and ELASTOCAST® C1006 from BASF Corporation (Florham Park, NJ).

Examples of crosslinking agents are amine based crosslinking agents selected from, for example, diethanolamine, triethanolamine, trimethylolpropane, ethylenediamine alkoxylation products having a hydroxyl number greater than 250 and combination. It should be understood that other crosslinking agents can also be used. For example, a polyol having a hydroxyl number greater than 250 and a functionality greater than 2 can be used as the crosslinking agent. An example of a suitable crosslinking agent is PLURACOL® 355, which is commercially available from BASF Corporation. In one example, the crosslinker is present in an amount from about 0.3% to about 5% by weight based on 100% by weight of the prepolymer.

In one example, the filler is an inorganic filler, a metal stearate, or a combination thereof. Some specific examples of fillers include citrate, carbonate, talc, clay, aluminum hydroxide, fly ash, barium sulfate, zeolite, aerosolized cerium oxide, molecular sieves, glass fibers, glass spheres, carbon black, nanoparticles. , conductive particles or a combination thereof. More specific examples of suitable fillers include metal stearates, carbonates, decanoates, and combinations thereof.

A cell opener may also be added having at least one of a paraffin wax, a cyclic and an aromatic hydrocarbon chain. For example, the cell opener is a mineral oil. However, it should be understood that other cell openers may be used, such as polyoxyphthalic acid, corn oil, palm oil, linseed oil, soybean oil, and defoamers based on particles such as ceria. The polyurethane formed using the cell opener is significantly less viscous than the polyurethane formed without the cell opener. In addition, the polyurethane formed using the cell opener does not have an oily residue. An example of a suitable cell opener is mineral oil available from Mallinckrodt Chemicals.

In one example, the prepolymer is commercially available. For example, the prepolymer is ELASTOCAST® TIP02, which is an isocyanate-based prepolymer available from BASF Corporation. ELASTOCAST® TIP02 is a prepolymer comprising a modified MDI component terminated with a polyether. ELASTOCAST® TIP02 is also a clear liquid having a urethane group of 2.5% by weight to 3.6% by weight based on 100% by weight of the prepolymer, and has a viscosity of about 30,000 mPa at 25 ° C. s to 60,000 mPa. s.

An example of a polyurethane coating disposed adjacent to the inflated spherical particles will now be described. The polyurethane coating disposed adjacent to the inflated spherical particles is typically the reaction product of the prepolymer and the polyol component.

The polyol component can be selected from any of the polyols identified above for the isocyanate reactive component. In one example, the polyol component is the same as the isocyanate reactive component. For example, both the polyol component and the isocyanate reactive component can be selected from the group consisting of polyether polyols capped with ethylene oxide. For example, both the polyol component and the isocyanate reactive component can be selected from the group consisting of ethylene oxide capped triol starting polyols. In another example, the polyol component can be different than the isocyanate reactive component.

The polyurethane formed by the reaction between the prepolymer having a residual isocyanate group as previously mentioned and the polyol component is a polyurethane gel. Additionally, it will be appreciated that as the polyurethane gel is formed, the polyurethane gel is applied to the aerated spherical particles. In other words, the polyurethane is formed and applied to the aerated spherical particles at substantially the same time.

An example of a method of forming a polyurethane on an aerated spherical particle generally comprises: providing a plurality of gas-filled spherical particles by reacting an isocyanate component with an isocyanate-reactive component to form a prepolymer, and combining pre-polymerization The polyol component and the aerated spherical particles react the prepolymer with the polyol component to form a polyurethane on the aerated spherical particles. In some cases, the mineral oil and catalyst are also combined with the prepolymer, the polyol component, and the aerated spherical particles. Details of the formation of the polyurethane on the inflated spherical particles are listed in the specific examples that will now be described.

In the specific examples mentioned immediately above, the polyurethane is formed using a batch process and applied to the aerated spherical particles. In the examples described below, the prepolymer is commercially available ELASTOCAST® TIP02 as mentioned above. In another example, a prepolymer is formed. The details of forming the prepolymer are listed below. In one example, a prepolymer of from about 10 lbs to about 11 lbs is preheated (eg, to a temperature of from about 100 °F to about 130 °F, more typically to about 120 °F) in a drum and preheated in another drum ( For example, a polyol component of from about 100 °F to about 130 °F, more typically to about 120 °F) from about 30 lbs to about 33 lbs. In this example, from about 80 lbs to about 85 lbs of corn starch is slowly added to a mixing vessel (such as a Hockmeier mixing vessel) containing inflatable spherical pellets. The aerated spherical particles and corn starch are mixed (e.g., about 30 minutes) using agitators and dispersers each operating at a frequency of from about 10 Hz to about 20 Hz and more typically at a frequency of about 15 Hz. The prepolymer is combined with the polyol component in another mixing vessel and the combination is blended at a frequency of from about 10 Hz to 20 Hz. This blending is performed, for example, for about 5 minutes to 10 minutes. A blend of the prepolymer and the polyol component is added to a mixing vessel containing the inflated spherical particles. The blend of the inflated spherical particles and the prepolymer and polyol component is mixed in a mixing vessel (e.g., using a stirrer and disperser operated at a frequency of about 10 Hz to 20 Hz for about 25 minutes to 30 minutes).

When mixing occurs in the mixing vessel, the prepolymer reacts with the polyol component to form a polyurethane. In addition, the salt mixture promotes the reaction between the prepolymer and the polyol component and drives the reaction to completion. The prepolymer and the polyol component are disposed when the polyurethane coating is disposed adjacent to a sufficient surface of the aerated spherical particles such that there is no active site on the surface of the aerated spherical particles for further reaction/bonding The reaction between the two is completed. In addition, the thickness of the polyurethane coating disposed adjacent to the inflated spherical particles is from 0.5 mm to 3 mm.

In some cases, one or more additives may be added to the mixing vessel when the polyurethane is formed. For example and as mentioned above, a mineral oil such as is commercially available from Calumet Specialty Products Partners, LP (Indianapolis, IN). Additives and catalysts of DRAEKOL® 7), such as tri-ethylamine catalyst, are added to the mixing vessel. Other additives such as a crosslinking agent, a chain extender, and a filler may also be added. Examples of such additives are listed above.

In the examples described above, corn starch is added to the aerated spherical particles prior to combining the prepolymer, the polyol component, and the aerated spherical particles. For example, the aerated spherical particles are mixed with corn starch in a mixing container prior to adding the blend (and additives) of the prepolymer to the polyol component to the mixing vessel. Alternatively, the aerated spherical particles may be added to the corn starch prior to combining the prepolymer, the polyol component, and the aerated spherical particles. Thus, corn starch and aerated spherical particles can be combined prior to combining the prepolymer, the polyol component, and the aerated spherical particles. The salty corn starch prevents the aerated spherical particles from cohesing in the mixing container such that the polyurethane coating is properly disposed adjacent to each of the inflated spherical particles. In other words, the salty corn starch prevents the aerated spherical particles from agglutinating (e.g., adhering to each other) in the mixing container such that the polyurethane coating is properly disposed on each of the inflated spherical particles. In another example, corn starch is not added to the aerated spherical particles, and in this example, the polyurethane is formed in the absence of corn starch.

In another example, a colorant (eg, a dye) can also be added to the mixing vessel (eg, before or after the blend of prepolymer and polyol component is added to the mixing vessel). Typically, the colorant imparts the desired color to the sphere (i.e., the inflated spherical particles having a polyurethane coating). For example, a blue dye can be added to cause the sphere to visually depict blue. The salt blue will provide a visual reference for the cooling effect of the sphere on the viscoelastic foam.

In another example, a prepolymer for batch processing as described above can be formed rather than purchased. In one example, the prepolymer is formed by reacting 4,4-MDI with a polyether triol in a heated reactor in the presence of a stabilizer such as benzamidine chloride.

After the polyurethane coating is placed in the vicinity of all of the inflated spherical particles, the spheres (i.e., the aerated particles having the polyurethane coating) are removed from the mixing vessel. It should be understood that there may be some residual components (such as residuals) after the formation of the polyurethane coating. Corn starch and uncoated inflated spherical particles). These residual components are not separated from the polyurethane coating and are instead dispersed in the viscoelastic foam. It is believed that the residual component does not affect the cooling effect imparted to the viscoelastic foam.

As mentioned previously, the polyurethane coating disposed adjacent to the aerated spherical particles may be a polyurethane gel. The polyurethane coating in the form of a gel is considered to be relatively flexible, and the Shore OO hardness value of the urethane coating is about 20 according to the OO hardness scale of ASTM D2240 type. To about 50. In another example, the polyurethane hardness coating has a Shore OO hardness value of from about 35 to about 50, as measured by the OO hardness scale of the ASTM D2240 type. ASTM D2240 is a standard test method for rubber properties - hardness scale hardness, and is based on the penetration of an indenter when forced into a material such as a polyurethane under specified conditions. The indentation hardness is inversely related to the penetration, and the indentation hardness depends on the elastic modulus and viscoelastic properties of the material. The test method can be used for several types of rubber hardness, including hardness type OO.

A method of forming a viscoelastic foam system is disclosed herein. The method comprises forming a sphere and dispersing the spheres in a viscoelastic foam. Inflated spherical particles (i.e., spheres) having a polyurethane coating are formed as previously described. The spheres are dispersed in a viscoelastic foam such as a viscoelastic polyurethane foam to form a viscoelastic foam system. Examples of dispersing the spheres in the viscoelastic foam are listed below.

For example, the viscoelastic polyurethane foam may be a single layer flexible foam such as a conventional single layer flexible foam, a highly elastic single layer flexible foam, and a closed cell. A single-layer flexible foam, an open-cell single-layer flexible foam, a molded single-layer flexible foam, a sheet-like single-layer flexible foam, and/or a combination thereof. Similarly, a single layer flexible foam can be further defined as a polyurethane monolayer flexible foam, a polyurea single layer flexible foam, and a polymer single layer flexible hair. Foam, single layer flexible foam rubber and the like. In one example, the single layer flexible foam is a polyurethane monolayer flexible foam. Non-limiting examples of the various generic single flexible foams to include PLURACEL ^® VE and PLURACEL ^® HR, all available from BASF Corporation (Florham Park, NJ) .

As used herein, the term "flexible" foam typically does not include a rigid foam. Further, the flexible foam suitable for the viscoelastic foam of the present invention may have specific physical properties measured according to ASTM, ISO and/or BIFMA standards (or any other standard recognized in the art) and / or highlight features. Non-limiting examples of various physical properties that can be measured and/or highlighted include density, support factor (compression modulus), airflow, ball bounce, compression modulus, compression set, durability, dynamic fatigue, flex fatigue , hysteresis, indentation force deflection (IFD), recovery, resilience, static fatigue, surface firmness, tear strength, tensile strength, and/or total vertical motion (TVM).

Viscoelastic foams such as viscoelastic polyurethane foams generally comprise the reaction product of an isocyanate material and an isocyanate-reactive material. The isocyanate material for the viscoelastic foam may, for example, be selected from any of the isocyanate components mentioned above. In another example, the isocyanate material can be an isocyanate-terminated prepolymer that is the reaction product of an isocyanate with a polyol and/or a polyamine. In another example, the isocyanate material can be any combination of isocyanate and/or isocyanate terminated prepolymers. Further, the isocyanate material can have any amount (%) of urethane groups and can have any viscosity.

In one example, the isocyanate-reactive material can be selected from any of the isocyanate-reactive components identified above for forming the prepolymer.

In an example, the viscoelastic foam further includes one or more additives. Such additives include, but are not limited to, crosslinking agents, chain extenders, catalysts, fillers, and color formers. Specific examples of such additives are provided above. Additional additives that may be included in the viscoelastic foam include surfactants, flame retardants, plasticizers, stabilizers, air release agents, wetting agents, surface modifiers, waxes, foam stabilizers, moisture Scavengers, desiccants, viscosity reducing agents, cell size reducing compounds, cell openers, reinforcing agents, mold release agents, antioxidants, compatibilizers, ultraviolet light stabilizers, thixotropic agents, anti-aging agents, lubricants, Coupling agent, solvent, Rheology promoters, adhesion promoters, thickeners, aerosol inhibitors, antistatic agents, antimicrobial agents, and combinations thereof.

In one example, the viscoelastic foam may also include a monohydric alcohol to increase the tan delta peak of the viscoelastic foam. In one example, the monohydric alcohol also softens the viscoelastic foam and slows recovery.

The viscoelastic foam may also include a cell opener having at least one of a paraffin wax, a cyclic and an aromatic hydrocarbon chain. Examples of the cell opener are listed above. The viscoelastic foam formed using the cell opener is significantly less viscous than those formed without the use of the cell opener. In addition, the viscoelastic foam formed using the cell opener does not have an oily residue. Further, the foam containing less than 2.5 parts by weight of the open cell agent in an amount of 100 parts by weight of the viscoelastic foam is less likely to retain fingerprints after the treatment. However, other components of the modified viscoelastic foam can also affect fingerprint recognition. In addition, the cell opener increases the gas flow through the foam and reduces the recovery time of the viscoelastic foam.

Further, the viscoelastic foam may contain a foaming agent such as a chemical foaming agent, a physical foaming agent, or a combination thereof. The chemical blowing agent is designed to react with the isocyanate component to form carbon dioxide. The physical blowing agent is designed to not react with the isocyanate component. Examples of physical blowing agents include hydrofluorocarbons (HFCs) such as HFC-134a, HFC-152a, HFC-245fa, HFC-365mfc, HFC-22, and combinations thereof.

As mentioned previously, the viscoelastic foam is the reaction product of an isocyanate material and an isocyanate-reactive material. In one example, the isocyanate material is on the A side of the reaction and the isocyanate reactive material is on the B side of the reaction. In one example, the A side of the reaction constitutes about 25% by weight based on 100% by weight of the viscoelastic foam and the B side of the reaction constitutes about 75% by weight based on 100% by weight of the viscoelastic foam. Further, the viscoelastic foam system includes a viscoelastic foam and a sphere dispersed in the viscoelastic foam. For example, a sphere is added to the B side of the reaction prior to reacting the isocyanate material with the isocyanate reactive material. For example, adding about 4% to 10% by weight of the spheres with 100% by weight of the B side of the reaction To the B side of the reaction. The spheres can be added to the isocyanate-reactive material (eg, in the first drum) while independently containing the isocyanate material (eg, in the second drum). The contents of the first and second rolls are combined and the isocyanate material is reacted with an isocyanate-reactive material to form a viscoelastic foam.

It will be appreciated that as the viscoelastic foam is formed (i.e., during the reaction of the isocyanate material with the isocyanate-reactive material), the spheres will disperse throughout the viscoelastic foam matrix. The spheres may be randomly or uniformly dispersed in the viscoelastic foam. In one example, as the viscoelastic foam is formed, the spheres will randomly disperse throughout the viscoelastic foam matrix. As used herein, the term "randomly dispersed" means that the sphere does not contain any form of orientation, alignment, positioning and/or distance between adjacent spheres in the viscoelastic foam. In one example, the spheres are present in the viscoelastic foam system in an amount from 3% by weight to 7.5% by weight based on 100% by weight of the viscoelastic foam system.

It should also be understood that when the sphere is incorporated into the viscoelastic foam, the polyurethane coating disposed adjacent to the inflated spherical particles is not chemically bonded to the viscoelastic foam. For example, the polyurethane coating disposed adjacent to the inflated spherical particles does not form a covalent bond with the viscoelastic foam. The salt letter can exhibit at most some hydrogen bonds between the polyurethane coating disposed adjacent to the inflated spherical particles and the viscoelastic foam.

An example of forming a viscoelastic foam system has been described above as adding a sphere on the B side of the reaction prior to actually reacting the isocyanate material with the isocyanate-reactive material (which comprises the spheres). Also contemplated herein, spheres may be additionally separately added; for example, the spheres may be contained in a third cylinder and then the contents from the first, second, and third rollers may be added together to form a viscoelastic foam. body. It is also contemplated that the spheres can be added from multiple sources; for example, some spheres can be added on the B side and other spheres can be added from the separate drum. Furthermore, the spheres may be added once the isocyanate material has reacted with the isocyanate-reactive material and after the reaction between the isocyanate material and the isocyanate-reactive material has begun.

Additionally, the spheres can be formed using the example methods described above and then followed by It is incorporated into the viscoelastic foam. Alternatively, the spheres may be formed again using the example methods described above and then stored, shipped or later incorporated into the viscoelastic foam.

As used herein, the term "about" is understood by those of ordinary skill in the art and will vary to some extent depending on the context in which the term is used. If there is a use of the term that is not known to those skilled in the art, it is assumed that the context of the term is used, and "about" means adding or subtracting at most 10% of a particular term.

It will be understood that one or more of the values described above may vary by ±5%, ±10%, ±15%, ±20%, ±25%, ±30%, etc., as long as the differences are still within the scope of the invention. It is also to be understood that the scope of the appended claims is not limited to the description of the embodiments and the specific embodiments, compositions, or methods, which may vary between the specific embodiments within the scope of the appended claims. With respect to any Markush group on which the specific features or aspects of the various embodiments are relied upon, it should be understood that the respective Markusi group may be independent of all other Markusi members. Each member receives different, special and/or unexpected results. Each member of the Markush group may be relied upon individually and/or in combination and provided with sufficient support for a particular embodiment within the scope of the appended claims.

It is also to be understood that any of the scope and sub-ranges of the various embodiments of the invention are to be construed as being All ranges, even if the values are not explicitly written in this article. It will be readily apparent to those skilled in the art that the scope and sub-ranges recited are fully described and the various embodiments of the invention can be practiced, and the scope and sub-ranges can be further described as related one-half, three-thirds One, one quarter, one fifth, and so on. As an example only, the range "0.1 to 0.9" can be further depicted as the lower third (ie 0.1 to 0.3), the middle third (ie 0.4 to 0.6) and the upper third (ie 0.7 to 0.9), which are individually and collectively within the scope of the appended claims, and which may be individually and/or collectively dependent, and provide sufficient support for particular embodiments within the scope of the appended claims. In addition, the language defining or modifying the scope, such as "at least", "greater than", "small" "," "not exceeding" and the like, it should be understood that the language includes sub-ranges and/or upper or lower limits. As a further example, the range "at least 10" inherently includes a sub-range of at least 10 to 35, a sub-range of at least 10 to 25, a sub-range of 25 to 35, etc., and each sub-range may be individually and/or collectively dependent and attached Particular embodiments within the scope of the patent application provide sufficient support. Finally, the individual numbers within the scope of the disclosure may be relied upon and provide sufficient support for the particular embodiments within the scope of the appended claims. For example, the range "2 to 8" includes various individual integers (such as 3) and individual numbers including decimal points (or fractions), such as 4.1, which may depend on and are specific to the scope of the appended claims. The embodiment provides sufficient support.

The subject matter of all combinations of independent and subsidiary items (single affiliation and multiple affiliations) of the patent application is expressly included herein, but is not described in detail for the sake of brevity. The present invention has been described in an illustrative manner, and it is understood that the terms Numerous modifications and variations of the present invention are possible in light of the above teachings.

Claims (20)

A viscoelastic foam system comprising: a viscoelastic foam; and a sphere dispersed in the viscoelastic foam, each sphere comprising: inflatable spherical particles; and a polymer disposed adjacent to the inflatable spherical particles a urethane coating comprising a reaction product of: i) a prepolymer comprising a reaction product of an isocyanate component and an isocyanate reactive component, the prepolymer comprising a urethane group of from 2.5% by weight to 3.6% by weight based on 100% by weight of the prepolymer; and ii) a polyol component; wherein the OO hardness scale is applied according to ASTM D2240 type The polyurethane OO hardness value on the aerated spherical particles is from about 20 to about 50. The viscoelastic foam system of claim 1, wherein the isocyanate reactive component is a polyether polyol. The viscoelastic foam system of claim 2, wherein the polyether polyol is capped with ethylene oxide. The viscoelastic foam system of claim 2, wherein the polyether polyol has a weight average molecular weight in the range of 3,000 to 6,000. The viscoelastic foam system of any one of claims 1 to 4, wherein the isocyanate component has a functionality of at least 2. The viscoelastic foam system according to any one of claims 1 to 4, wherein the isocyanate component is selected from the group consisting of 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, A group consisting of 4,4'-diphenylmethane diisocyanate and combinations thereof. The viscoelastic foam system of any one of claims 1 to 4, wherein the polyol component is a polyether polyol. The viscoelastic foam system of any one of claims 1 to 4, wherein the isocyanate reactive component is the same as the polyol component. The viscoelastic foam system of any one of claims 1 to 4, wherein the aerated spherical particles have an expandable thermoplastic shell encapsulating a gas. The viscoelastic foam system of claim 9, wherein the aerated spherical particles have an effective particle diameter in the range of 30.0 μm to 50.0 μm. A sphere for a viscoelastic foam, the sphere comprising: inflatable spherical particles; and a polyurethane coating disposed adjacent to the inflatable spherical particles, the polyurethane coating comprising the following Reaction product of each: i) a prepolymer comprising a reaction product of an isocyanate component and an isocyanate-reactive component, the prepolymer comprising from 2.5% by weight to 3.6% by weight of the amine based on 100% by weight of the prepolymer a urethane group; and ii) a polyol component; wherein the Shore OO hardness of the polyurethane coating disposed adjacent the gas spheroidal particle is measured according to an OO hardness scale of the ASTM D2240 type The value is from about 20 to about 50. The sphere of claim 11, wherein the isocyanate reactive component is a polyether polyol terminated with ethylene oxide. The sphere of claim 11, wherein the isocyanate-reactive component is a polyether polyol having a weight average molecular weight in the range of 3,000 to 6,000. The sphere according to any one of claims 11 to 13, wherein the isocyanate component is selected from the group consisting of 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'- A group consisting of diphenylmethane diisocyanate and combinations thereof. The sphere of any one of clauses 11 to 13, wherein the inflatable spherical particles comprise an expandable thermoplastic shell encapsulating a gas. The sphere of claim 15, wherein the inflatable spherical particles have an effective particle size in the range of 30.0 μm to 50.0 μm. A method of forming a viscoelastic foam system, the method comprising the steps of: A. forming a sphere by providing a plurality of inflatable spherical particles; and coating the plurality of inflatable spheres with a polyurethane Shaped particles; wherein the polyurethane has a Shore OO hardness value of from about 20 to about 50 according to the OO hardness scale of the ASTM D2240 type; and B. the spheres are dispersed in the viscoelastic foam To form the viscoelastic foam system. The method of claim 17, wherein the coating step is further defined by reacting an isocyanate component with an isocyanate-reactive component to form a prepolymer, wherein the prepolymer comprises 100 of the prepolymer 5% by weight to 3.6% by weight of a urethane group; and reacting the prepolymer with a polyol component to form the polyurethane as the plurality of gas-filled spherical particles Coating. The method of claim 18, further comprising combining the prepolymer, the polyol component, and the plurality of aerated spherical particles during the reacting step to react the prepolymer with the polyol component to form The polyurethane. The method of any one of claims 17 to 19, wherein the viscoelastic foam comprises a reaction product of an isocyanate material and an isocyanate-reactive material, and wherein the spheres are dispersed in the viscoelastic foam The step is further defined as: combining the spheres with the isocyanate-reactive material; and combining the isocyanate material with the isocyanate-reactive material comprising the spheres a reaction; wherein the spheres are dispersed in the viscoelastic foam during the reaction step.