SI23066A2 - Spring mattress and pillow made of flexible foamed polyurethane with thermally adaptable microcapsules - Google Patents

Abstract

A spring mattress and a pillow are described, which comprise at least a part of flexible foamed polyurethane, where preliminarily microcapsulated thermally adaptable substances with the liquid-solid phase transition within the temperature range from 18 to 37 degrees Celsius are integrated in the polyurethane.

Description

Mattress and pillow made of flexible foamed polyurethane with heat-adjustable microcapsules

The present invention relates to a mattress or bed pillow made of flexible foamed polyurethane.

As is known, mattresses and pillows are used as a resting body on the bed to rest or recover the wearer. These items are procured for both private domestic use and the public sector (eg hospitals, sanatoriums, hotels) where there are even stricter requirements.

They are also known to make these items from flexible polyurethane material.

Polyurethane chemistry is based on the reaction of isocyanides with molecules containing active hydrogen atoms. The -NCO groups contained in the isocyanate molecule react rapidly in the presence of suitable catalysts with hydrogen atoms bonded to atoms that are more electronegative than carbon. This reaction leads to the formation of the desired polymeric structure; in this regard, a gas production reaction occurs, e.g. carbon dioxide (arising from the reaction of isocyanate with water).

Typically, a continuous batch production process is performed for the manufacture of pillows and pillows. From the reservoirs, sized and constructed for the raw materials and additives used, chemical components move - by means of circulating / dosing pumps - along the conduits for connection to the mixing and distribution head. Different mixing parameters can be varied in the mixing head. The distributor head leads to the foaming line, where a high and wide carpet of foamed polyurethane is continuously produced, which is then cut to the desired length to produce long polyurethane blocks. The blocks are then stored on aging boards until the next cutting into slabs, boards or rolls of a size suitable for producing the finished item.

Many types of polyurethane pillows and mattresses are already available on the market, where various individual polyurethane sheets (in density, mechanical behavior, sanitary characteristics, etc.) are joined together or used thin sheet rolls together with fabric and material to obtain the final the product that best meets the user's requirements.

Although the polyurethane itself has good thermal properties along with good perspiration quality, the applicant has set himself a purpose to offer an improved pillow and mattress that offer the user a comfortable, comfortable feeling at different temperatures. In particular, it aims to offer a mattress that can contribute to the adjustment of body temperature, providing greater comfort in all those cases where the user's body - for various temporary or pathological reasons - is too warm or cold.

Such a purpose is achieved by the product as described by its essential features in the annexed main claim.

Other inventive aspects of the mattress and pillow are described in the dependent claims.

The further features and advantages of the object in the sense of the patent with respect to the duration will certainly be more apparent from the following detailed description of the preferred embodiment in the form of a case and shown in the accompanying drawing, which is a curve showing the result of the comfort that can be achieved with the object in the sense of the patent with the shortened duration.

The Applicant has begun to select substances that undergo a phase change that releases / absorbs heat energy over a time interval, which may be advantageous. During the phase change, such phase change materials, also called PCMs, release latent heat (transition from liquid to solid state) or absorb latent heat (transition from solid to liquid state), thereby becoming able to dissipate or supply heat to the surrounding environment in proportion to its volume.

The phases to be considered are solid and fluid because gaseous would present significant practical problems, mainly related to volume changes, making it of little use.

Particularly preferred substances for specific use, which are applicable here - which will be referred to below as thermally adaptable substances - are so-called. PCMs with high latent condensing heat having a state change temperature in the interval between 18 and 37 ° C corresponding to a temperature interval suitable for feeling comfortable for the user's body.

Such substances exist both in organic form (eg paraffin or fatty acids) as well as inorganic form (eg hydrated salts such as M _n H ₂ O) and also in eutectic forms. Furthermore, they are capable of storing 5 to 14 times more energy than other reference substances, such as water.

Preferably, in the application submitted, such thermally flexible substances are selected from paraffins.

In the sense of the present patent, the shortened duration of such a substance, prepared in granular or powder form, is first micro-encapsulated.

A technology called microencapsulation allows the substance to be contained within the shell and to protect it from external influences. The microcapsules can vary in size between 3 and 800 pm. The microencapsulation technique is known in itself and will not be described in further detail. In the specific case of the application of suitable thermally adaptable substances, the shell of each microcapsule may be of one of the following preferred materials: polyesters, polyacrylates, vinyl polymers or waxes.

When the microspheres of the selected thermally adaptable substance are obtained, they are subjected to a dispersion process in a reaction compatible reaction carrier for the formation of foamed polyurethane. We do not use dispersion techniques such as spherical or cylindrical to minimize mechanical stress on the mixture.

The carrier may be of either the reactive type by remaining bound in the polymer matrix or the non-reactive type. In the first case, its presence during chemical formulation should be further considered to ensure that the polyurethane polymerization reaction occurs as desired; in the second case, it is easy to select a substance that does not compromise the requirements of the sectoral standards relating to the environment, workers' health and safety, and to the health of the user, taking into account the scope of the end product. When choosing a carrier, consideration must also be given to aspects of chemical compatibility with the nature of the membrane of the microsphere.

As an example of a reactive carrier, polyol is mentioned herein; as a non-reactive carrier e.g. we consider non-phthalic softener.

In addition to the carrier, if it is necessary to maintain a good homogeneity of dispersion, wetting and stabilizing additives can be introduced into the same dispersion.

The dispersion thus obtained, consisting of microspheres (micro-encapsulated substance with phase change) and polyol and any wetting agent, is used in the manufacture of flexible foamed polyurethane.

The finished product (pillow or mattress), which can be obtained in terms of a patent with a short duration, can be manufactured using various technologies for the production of flexible foamed polyurethane, both from continuous blocks and by casting.

Densities of polyurethanes generally vary from 25 to 100 kg / m ³ ; the isocyanates may be TDI (toluene diisocyanate), MDI (methylene diphenylisocyanate) and IPDI (isophorone diisocyanate), the nature of the polyol may be the usual high elastic ethers based on ethylene oxide and / or propylene oxide, and esters, possibly crosslinked, to increase the hardness of the polyana. We can also use plant-based polyols, ie obtained from renewable sources.

In a polyurethane formulation, the weight percentages of additional dispersion (containing microcapsules) relative to the microspheres per foam final mass can vary - depending on the density and / or end use of the polyurethane - between 3 wt. % and 30 wt. %.

The treatment identified as preferred in the context of the present patent for shortened duration is mass treatment: therefore, it provides for the use of a piston, gear or peristaltic pump to dispense additional dispersion directly into the polyurethane mixing chamber.

The resulting polyurethane is cut and molded, in the case of continuous or non-continuous block production, to obtain mattress sheets, thin sheets for insertion into quilts or pillows, used in a mold to obtain cast mattresses and pillows.

In particular, the mattress cover can be obtained with foamed polyurethane, which includes a thermally adjustable component, with continuous fabrication of the panels then bonded to the fabric; while the mattress filling can be formed in one of the following ways:

A. a single polyurethane board or board with a heat-adjustable component;

B. two jointed panels, preferably using polyurethane produced with a heat-adjustable component in the surface panel alone (i.e., one that remains closest to the user's body);

C. three jointed panels, preferably using polyurethane produced by technology within the meaning of a patent with a shortened duration in surface panels only, possibly with different thermally adaptive properties (winter side, summer side).

In the second case (B), the surface plate generally has lower CV ₄₀ (kPa) pressure values to give a greater sense of comfort, while the lower panel serves as support with higher CV ₄₀ (kPa).

In the third case (C), both surface panels generally have lower CV ₄₀ pressure values (kPa) to give a greater sense of comfort, while the middle or core panel acts as a support with higher CV ₄₀ pressure values (kPa).

In all cases, the surface surfaces of the panels on the user facing side may be flat or have different patterns. Samples have the purpose of creating surfaces of varying hardness and / or of producing a massage effect.

Flexible foamed polyurethanes used in the formulation in the sense of a shortened patent for the manufacture of mattresses, quilts and pillows may be:

- conventional polyethers;

- highly elastic polyethers;

- viscoelastic.

Viscoelastic foams should preferably be used for surface panels or inside quilts placed at the top of the mattress, arranged very close to the wearer: in fact, due to their tendency to hold the body better than other foams, they are more suitable for heat-adaptive processing than for their supporting ones. middle or lower panel properties.

As mentioned in the luxury mattresses (type C) we can guarantee the use of two sheets of polyurethane with different heat-adaptive properties. We get a mattress / pillow that has:

- winter side having polyurethane on the surface with thermally adjustable microspheres with a lower melting point PCM;

- Summer side having polyurethane on the surface with thermally adjustable microspheres with higher melting point PCM.

For the final mattress cover, natural or synthetic fabric can be used as well as just fabric, quilts (which may include thermally flexible material), removable or non-removable blankets.

For the manufacture of a pillow, it is generally preferable to use a single flexible foam polyurethane with a heat-adaptive property (subsequently molded in the case of a continuous block production) with different patterns.

The mattress, and especially the pillow, can preferably be made by casting.

If we are to obtain finished pieces by casting instead of forming a block made with a continuous technique, it is possible to introduce - in addition to what was stated above - a further original feature.

During the mold preparation phase, a layer of microspheres (micro-encapsulated thermally adaptable substance) is first applied to the inner surfaces of the mold. The mold surfaces affected by this process are at least those facing the end user in the end product.

The above action is intended to temporarily and reversibly attach the microspheres to the inner surfaces of the mold. To improve adhesion with uniform thickness of the microspheres to uneven surfaces, it is possible to pre-mount a film of the same decision medium normally used to facilitate the removal operations of the final piece from the mold on the inner surfaces of the mold. The microsphere layer thus obtained has a thickness of the order of magnitude of the diameter of the microspheres, i.e. between 3 and 800 p.m.

When the mold was resealed and injected with the polyurethane-based reaction mixture, the microspheres were automatically embedded in the polymer matrix on the surface of the cast object by transferring from the inner walls of the mold.

The following further advantages are obtained:

- deciding the final piece from the mold at the end of the process is further facilitated because the microsphere layer acts as a decision powder;

- The concentration of microspheres near surface surfaces is significantly increased, thus increasing the potential for thermal regulation.

The accompanying drawing shows the temperature curve of the polyurethane material against time. The curve is a testament to the results that can be obtained with an object in terms of a patent with a reduced duration. In particular, the heat-adaptive effect of the mattress becomes apparent when the mattress is made of flexible foamed polyurethane sheets incorporating PCM microcapsules or microspheres, with the panels constituting either the core or outer sides of the mattress.

A sample of flexible foamed polyurethane containing thermally flexible microcapsules within the meaning of a shortened patent was subjected to the ASTM D 7024 test.

The test was performed at two different exit temperatures: the first graph (outer) was obtained when starting from a temperature of 41 ° C, while the second graph (internal) was obtained when starting from about 25.5 ° C. It may be mentioned that, although the same energy was dissipated and supplied with the same amount of material, if - the second graph - the temperature circulates around the critical / operational temperature of the microcapsules (ie around the temperature where the phase change occurs), the polymeric material is exposed to smaller temperature variations than the sample at operating at temperatures outside the critical / operational temperature of thermally adaptable PCM microcapsules contained in microcapsules embedded in a polymeric material, they delivered latent heat to the polymeric material during the cooling phase, while latent heat was discharged from the polymeric material during the heating phase.

This test gives a clear picture of the favorable advantages of an object in terms of a patent with a short duration, which allow the user to experience increased comfort after using a mattress or a pillow in the sense of a patent with a short duration. The heat-adjustable effect is able to reduce the temperature points, which greatly increases the comfort of the mattress or pillow wearer, designed in the sense of a shortened patent.

It should be noted that the heat-adaptive effect can be extended over a wide range of different temperatures (18 to 37 ° C) by selecting suitable mixtures of different PCM microcapsules embedded in the same material using the same mass treatment process.

As can be seen from the above, the original system proposed in the patent of the shortened duration, the objects mentioned in the foregoing notes have been fully achieved.

In particular, a mattress or pillow made of flexible foamed polyurethane with the addition of microcapsules of thermally adaptable substances, with a phase change over a temperature interval of 18-37 ° C (an interval within which the heat of the human body is capable of causing the melting of thermally adaptable material by phase change), enable it to provide the end user with greater comfort due to energy storage and the effect of release in the form of heat produced by microspheres. The microspheres create a microclimate that compensates for the temperature peaks, improving sleep quality or prolonged recovery.

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However, it is understood that the protection afforded by the patent described above with a reduced duration is not limited to the individual embodiment shown, but extends to any other construction variant that achieves the same utility.

Claims (6)

A mattress or bed pillow comprising at least a portion of flexible foamed polyurethane, characterized in that pre-micro-encapsulated, thermally adaptable substances are incorporated in the polyurethane by changing the liquid / solid phase in the temperature range 18 to 37 ° C. A mattress or pillow according to claim 1, wherein the microencapsulated thermally adaptable substances are embedded in a portion of the foamed polyurethane at least near the surface adjacent to the wearer's body. A mattress or pillow according to claim 2, consisting of different layers connected to one another, in which at least a surface layer embedded, a micro-encapsulated thermally adaptable substance. A mattress or pillow according to claim 2, obtained by casting, wherein the microencapsulated thermally flexible substance is a material uniformly represented in the surface portion, the material being applied to the inner surface of the mold prior to injection of polyurethane during its manufacture. Mattress or pillow according to any one of the preceding claims, wherein the thermally adjustable substances are paraffins. Mattress or pillow according to any one of the preceding claims, wherein the thermally adaptable substances are micro-encapsulated and dispersed in a carrier belonging to the polyol or non-phthalic softener family.