KR20000069657A - Lipophilic adhesive for secure topical attachment to the skin and comfortable removal - Google Patents

Abstract

The present invention relates to a lipophilic topical adhesive for attachment to the skin. In particular, the present invention relates to topical adhesives that can be used to adhere to the skin of areas where body fluids are to be absorbed. Topical adhesives adhere firmly and have a good feel to the skin when applied and do not cause discomfort when peeled off. This is done by screening out the chemical composition and flow characteristics of the topical adhesive.

Description

LIPOPHILIC ADHESIVE FOR SECURE TOPICAL ATTACHMENT TO THE SKIN AND COMFORTABLE REMOVAL}

Conventional prior art in the field of topical adhesives for adhering to the skin has developed particularly in disposable bands, plasters and bandages. However, these products are usually applied in emergencies where wounds on the wearer's skin and the absorption of body fluids secreted from the wound are required. In this regard, aspects of comfort and ease of use and application, painless removal and separation of absorbent product performance are based on criteria such as wound sterility, support for healing recovery, and mechanical protection. In addition, absorbent products covering such wounds are most often attached to areas of the skin where hair can be removed or little or no hair grows prior to application of the absorbent product.

The present invention relates to topical adhesives that are particularly useful in absorbent products for absorbing body fluids that are naturally secreted from the body even if a wound does not occur. For example, it relates to topical adhesives that are particularly useful for attaching sanitary napkins or pantyliners in the genital area. It is also possible to suitably use the adhesives of the invention, for example, in urinary incontinence devices worn in the genital area or sweat pads worn under the armpits of patients.

The invention also provides a protective product, such as a genital-, knee- or elbow protector, or a bandage; Clothing, such as a bra, surgical gown, or a piece of clothing while fitting at the time of tailoring; Nasal plaster; Prostheses such as breast substitutes or wigs; Warming wraps, for example, to alleviate or insulate bruises during menstrual pain, joint pain, back pain, exercise or labor; Ice wraps, such as to relieve bruises or reduce swelling; hearing aid; Facial protective masks; A topical adhesive particularly useful for decorative products such as jewelry, earrings, ornaments, tattoos, goggles or other eyewear. These products are not used for the absorption of body fluids. The adhesive of the present invention may, for example, attach a wig to the scalp or appropriately attach an elbow or knee protector to the body surface (substantially elongated or wrinkled).

In addition, the present invention may relate to topical adhesives that are particularly useful for functional products such as cosmetic or drug delivery products that provide skin with substances such as skin therapeutic substances, creams, lotions, hormones, vitamins, deodorants, or drugs. Alternatively, the cosmetic or drug delivery material may provide a substance emanating from the skin, such as pesticides, inhalation drugs or perfumes, and the lipophilic adhesives of the invention are not attached to the skin but are cosmetic cosmetics (lipsticks, color eye cosmetics). It can be used in functional products as a component of a product that must remain on the skin for a long time, such as, stage cosmetics) or cleaning products (hand detergents, face masks, especially pore hygiene cleaners). These products are not used for body fluid absorption. For example, the adhesive of the present invention can be used to attach a vitamin plaster to the skin or to properly attach an inhaled drug release product to the breast. Incorporating the adhesive into the cosmetic product does not remove the problem and prevents it from being erased.

Topical adhesives for use in absorbent products, such as sanitary napkins or pantyliners, are generally described in US Patent Application H1602 or WO 96/33683. Some of the more detailed description of the adhesives is described in PCT patent WO 95/16242. This document discloses a sanitary napkin with a topical adhesive applied along its entire circumference on the wearer facing surface of the sanitary napkin. The problem in this document is mainly a firm attachment to the skin but also mentions the problem of detaching the product after use without causing severe pain to the wearer.

WO 95/16424 discloses in more detail the criteria for topical adhesives in terms of fluidity criteria. However, as the fluidity criteria taught include commercially available hair loss (i.e., hair removal) compositions such as STREP MIELE (R), which is available from Laboratori Vaj SpA, Italy, the literature makes the product painless. I rarely consider the problem of stripping. Topical adhesives mentioned in WO 95/16424 include current pressure sensitive adhesives used to attach sanitary napkins to undergarments. In addition, the document only confirms the static flow characteristics of the topical adhesive and does not mention the dynamic flow characteristics.

WO 96/13238 discloses a topical adhesive model that is frequency dependent. However, for example, all measurements disclosed on page 9 were made at temperatures between −60 and + 120 ° C. and actual frequencies between 0.1 and 100 rad / s. At the application temperature (typical bathroom, ie storage temperature of about 20 ° C.), the Williams-Landel-Ferry (hereinafter WLF) equation was used to obtain the required data.

These WLF equations are experimental and valid only at certain limits, so they cannot be used to extrapolate to temperatures below the glass transition temperature of the polymer adhesive, nor can WLF be used based on values obtained below the glass transition temperature. A detailed description of the WLF equation and its application can be found in Z. Tadmor and CGGogos, Principles of Polymer processing, John Wiley & Sons or JDFerry, Viscoelastic Properties of Polymers. , John Wiley & Sons. It is not described in WO 96/13238, so the application of the disclosed data cannot be evaluated.

EP-638 303 discloses the use of a topical adhesive on the side cuff of a sanitary napkin to keep the cuff in an upright position. Swiss Patent CH-643730 discloses a very long sanitary napkin with a rounded outer edge, with a topical adhesive applied to the four corners of the outer edge to provide a topical adhesive area far enough outside the pubic growth area. Neither of these patents mentions an adhesive composition.

Based on the above description of the prior art, the present invention aims to provide a lipophilic topical adhesive that is firmly attached and can be painlessly removed from the skin. Another object of the present invention is to ensure that no adhesive remains on the skin or hair when detached.

Another object of the present invention is to ensure that the lipophilic topical adhesive does not feel cold or unacceptable temperature in application despite the difference in skin temperature and adhesive temperature.

In addition to the above object of the present invention, topical adhesives preferably provide additional effects such as transporting / dispersing compounds or compositions that are beneficial to the skin or generally the body or to the protection of the body. Also preferred are topical adhesives that are breathable or water vapor transmissive or water vapor / sweat absorbent that do not affect the natural skin condition.

Summary of the Invention

While the present invention discloses the use of such adhesives on disposable absorbent articles to adhere topical adhesives to wearers of disposable absorbent articles, other uses of the present invention are also possible.

In addition, the present invention is directed to protective products such as genital-, knee- or elbow-protective, or bandages; Clothing, such as a bra, surgical gown, or a piece of clothing while fitting at the time of tailoring; Nasal plaster; Prostheses such as breast substitutes or wigs; Warming wraps, for example, to relieve menstrual pain, arthralgia, back pain, bruising pain during exercise or labor or just to keep warm; Ice wraps, such as to relieve bruises or reduce swelling; hearing aid; Facial protective masks; It is useful for attaching decorative products such as jewelry, earrings, ornaments, tattoos, goggles or other eyewear to the skin or clothing. Such products are nonabsorbent for body fluids.

In addition, the present invention may be useful for affixing functional products to the skin or improving the function of such products when they are applied on the skin. A functional product is a cosmetic or drug delivery product that provides skin with a substance such as a skin treatment substance, cream, lotion, hormone, vitamin, deodorant, or drug, or the cosmetic or drug delivery substance may be used with pesticides, inhalation drugs, or perfumes. It is also possible to provide substances which emanate from the skin, and also the adhesives of the present invention are not attached to the skin but may be cosmetic cosmetics (lipsticks, color eye cosmetics, stage cosmetics) or cleaning products (hand detergents, face masks, especially pore hygiene cleaners). It may be included in the functional product as a component of the product that must remain on the skin for a long time. Such products are nonabsorbent for body fluids. The use of topical adhesives allows the product to adhere firmly to the wearer's skin and support the product's functionality. The term "functional" in this regard means that the product can exert an additional function which is supported or improved by the adhesive of the invention after it is placed on the skin. The product generally has a wearer facing surface and an outward facing surface.

When used on disposable absorbent articles, the lipophilic topical adhesives of the present invention are intended to be topical adhesives that adhere the product to a wearer. Disposable absorbent articles, such as sanitary napkins, panty liners, urinary incontinence products or armpit sweat pads, typically have a wearer facing and an outward facing. The product includes an absorbent core between the wearer's opposing and outward surfaces to absorb liquids secreted from the wearer such as urine, stool, menstrual blood, sweat and vaginal secretions. Topical adhesives allow the product to adhere to the wearer's facing surface.

A continuous detailed analysis of the general situation that arises from the application of a disposable absorbent product to the removal of such an absorbent product shows the desired performance objectives, specifically firm initial attachment, firm attachment during use, and painless removal at the end. In order to achieve this, it is shown that certain adhesive characteristics need to be preferably satisfied. Features contemplated in this regard are the elastic modulus describing the elastic aspect of the material and the viscous modulus describing the viscous aspect of the adhesive material.

The viscous aspect of the adhesive can be interpreted as indicating an indicator of the ability of the adhesive to adhere quickly and adhere firmly. The elastic aspect can be described as an indicator of the "hardness" aspect of the adhesive. This value is the basis for good initial adhesion. Combinations of these appear to be indicative of the force required to remove them. The relationship between elastic and viscous modulus is considered as an indicator of how much of the energy it takes to release is dissipated in the adhesive and how much of the energy can be used to cause actual peeling.

The relationship between elastic modulus and viscous modulus, as well as their dynamic aspects, is an important key to providing topical adhesives for early and consistently firm attachment and easy and painless peeling.

Topical adhesives have an elastic modulus at 37 ° C. (100 ° F.) abbreviated as G ′ ₃₇ and a viscous modulus at 37 ° C. (100 ° F.) abbreviated as G ″ _{37. The} adhesive also has a G at 100 rad / sec frequency. dynamic elastic aspect _"37 and 1rad / sec G in frequency, the difference between ₃₇ (△ G _'37) and 100rad / sec G' ₃₇ and G at 1rad / sec frequency" mode, a dynamic viscosity difference between the ₃₇ at frequency (ΔG ″ ₃₇ ).

The topical adhesive according to the invention preferably satisfies the following conditions.

G ′ ₃₇ (1 rad / sec) is in the range 1500 to 20000 Pa, preferably in the range 1500 to 15000 Pa, most preferably in the range 3000 to 10000 Pa.

G ″ ₃₇ (1 rad / sec) is in the range of 100 to 15000 Pa, preferably in the range of 100 to 10000 Pa, most preferably in the range of 300 to 5000 Pa.

_{G '37 (1rad / sec)} / G "37 (1rad / sec) ratio is in the range of 3 to 30 range.

And _{(G '37 (100rad / sec} ) -G "37 (100rad / sec)) / (G' 37 (1rad / sec) -G" 37 (1rad / sec)) ratio of 0.5 or more, preferably 0.7 to 3 range, most preferably 1 to 1.8.

_{△ G '37 / G' 37} (1rad / sec) of the ratio is 1.5 or less, preferably less than 1, or most preferably 0.8 or less, or △ G _'37 is more than 10000Pa, preferably less than 5000Pa , and most preferably is below 2000Pa, or _{△ G '37 / G' 37} (1rad / sec) ratio is 1.5 or less, preferably 1 or less, and most preferably at the same time, 0.8 or less △ G _'37 is the It is 10000 Pa or less, Preferably it is less than 5000 Pa, Most preferably, it is 2000 Pa or less.

The value of at least the ΔG ′ ₃₇ / G ″ ₃₇ ratio for frequencies ranging from 1 to 100 rad / sec is preferably at least 3.3, more preferably at least 5, most preferably at least 10 and at the same time the frequency in all parts. The difference should not exceed about 30, preferably 20.

The flowability aspect can also be related to the value of the glass transition temperature (Tg). For topical adhesives according to the invention the glass transition temperature should preferably be below -15 ° C, more preferably below -20 ° C and most preferably below -25 ° C.

Flowability aspects and tolerability of topical adhesives may be related to specific heat capacity. Preferably the specific heat capacity of the topical adhesive is less than 4J / g / K, more preferably less than 3J / g / K, most preferably less than 2J / g / K.

In addition, the flowability aspect and tolerance of the topical adhesive may be related to the specific thermal conductivity of the adhesive. The specific thermal conductivity should preferably be as low as possible, preferably 1 to 0.1 W / m / K, most preferably 0.6 to 0.1 W / m / K.

If the fluid conditions are met, the adhesive also serves as a criterion for the commercial use of the adhesive and satisfies conditions such as sufficient tack (which prevents the adhesive from remaining on the skin), apparent to those skilled in the art. Adhesive compositions that meet the above criteria may be used as topical adhesives for the aforementioned products or as ingredients in a blend of functional products, in particular as topical adhesives for disposable absorbent products, provided they are used for humans or animals during use. They must meet the usual requirement that they be safe and generally safe after disposal of the absorbent product.

The criteria for hygienic appearance and a pleasant feel upon contact are often important so that an adhesive composition that is transparent or white and that does not feel cold and unpleasant upon application are preferred.

The fluid conditions and other considerations are as follows: polystyrene-block-poly (ethylene-lan-butylene) -block-polystyrene (more than 70% by weight of ternary block and more than 25% by weight of styrene) Molecular weight is greater than 60,000) 3 to 15% by weight, preferably 5 to 10% by weight, polystyrene-block- (polyethylene-lan-butylene) -block-polystyrene (70% by ternary block content) as second copolymer 0 to 9% by weight, preferably 0 to 6% by weight, oil as plastic compound (paraffin fraction is more than 50% by weight and aromatic fraction is 5% by weight) 20 to 95% by weight, preferably 30 to 60% by weight, 0 to 50% by weight of hydrogenated cycloaliphatic adhesive resin, preferably 30 to 50% by weight, 0 to 10% by weight of additives such as antioxidants or gel stabilizers %, Preferably It can be satisfied by a particularly preferred adhesive composition of the invention comprising 0.3 to 1% by weight antioxidant and 0 to 1% by weight gel stabilizer. The polystyrene-block- (polyethylene-lan-butylene) -block-polystyrenes as the first and second copolymers are preferably styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-ethylene-butylene-styrene, styrene- It is preferably selected from the group consisting of styrene-block-copolymers of the ethylene-propylene-styrene type. The oil is preferably selected from the group consisting of natural oils and synthetic oils such as vegetable oils, mineral oils or mixtures thereof.

The present invention relates to a lipophilic topical adhesive for attachment to the skin. More specifically, the present invention relates to topical adhesives that can be used to adhere to the skin of areas where body fluids are to be absorbed, and in particular can be used to attach sanitary napkins, panty liners, adult urinary incontinence products or sweat pads. In addition, the lipophilic topical adhesives of the present invention may be used as protective products, garments, prostheses, thermal wraps, ice wraps, hearing aids, face protection masks, ornaments, eyewear, or cosmetics or drug delivery products that provide certain substances to the skin. Other products, such as functional products, can be used to adhere to the skin. In addition, the lipophilic topical adhesive of the present invention can be used in functional products as a component of a product that does not adhere to the skin but must remain on the skin for a long time such as a cosmetic cosmetic or a cleaning product. Topical adhesives adhere firmly and remain for a long time and have a good feel to the skin during application and do not cause discomfort when peeled off. This is accomplished by screening the chemical composition and flowability characteristics of the topical adhesive.

Topical Adhesive

Topical adhesives according to the invention are applied directly to the skin. In specific applications the adhesive may be used in sanitary napkins that are typically applied around the liquid secretion area of the genital area of a female user. The term "skin" according to the invention refers not only to the specific dermis of the user, but also to the mucosal tissue, and also to the hair generally present in the genital area of the sanitary napkin user.

In order to fix the absorbent article according to the present invention on the skin, a topical adhesive should be provided in a certain area on the skin facing surface of the article.

Various designs are contemplated for sanitary napkins, but topical adhesives are preferably provided along the circumferential edge of the topsheet such that the central area of the product does not contain adhesive. This ensures the most appropriate placement of the sanitary napkin so that the liquid-permeable topsheet area without the adhesive is placed adjacent to the opening where the fluid is secreted so that the secreted liquid is immediately moved into the absorbent structure of the absorbent product without the possibility of leakage or spillage. .

Physical, Fluid, and Adhesive Characteristics of Topical Adhesives

Although topical adhesives, such as pressure sensitive adhesives, are used on the hair and mucosal tissues of human skin, the topical adhesive compositions are typical of pressure sensitive adhesives (hereinafter referred to as PSAs) based on the most characteristic flowable aspects that identify the material. I understand that there is a difficulty in regard to this.

Indeed, as those skilled in the art of adhesives know, the biggest feature that distinguishes PSAs from other materials that can temporarily stick objects (e.g. water between two glass plates) is their fluid parameters, in particular elastic modulus. The fact that (G ') varies greatly depending on the frequency of the stress applied. More specifically, the G 'of the PSA may increase by more than a few orders while the frequency of the applied stress varies from normal binding frequency to normal resolution frequency, ie 1 rad / sec to 100 rad / sec as described below.

As a first result, it is concluded that it is unacceptable to define a material to be used as a "topical adhesive" by providing a fluid variable value, especially the G 'value at a fixed frequency. This may be misjudged as it will include materials that have no practical value in the absence of other features. Therefore, fluid features should be based on dynamic considerations.

This applies not only to the elastic modulus G 'but also to the viscous modulus G "and thus also to tan (δ) = G" / G'. A typical PSA not only has a high variation of G 'across the frequencies considered, but also closer to or much higher than the G' value (ie, especially tan (δ) is about 1 or much greater than 1 in the typical frequency of the solution sum). It is well known to have a greater G " than).

While not being bound by theory, this is largely due to the fact that much of the energy applied to the solution sums is dissipated in the adhesive (and therefore not effective in generating solution sums), which is interpreted as a macro-generating record of very high adhesion. Can be.

As mentioned above, the material useful as a topical adhesive according to the present invention has a flow characteristic mainly measured at a reference temperature of 37 ° C. (general human body temperature) and a range of frequencies. In the application of absorbent articles (eg sanitary napkins) containing topical adhesives, it has been found that the contact of the adhesive is formed at a low frequency while the solution bond occurs at the rate of tearing off the product. This rate was expressed in 100 rad / sec frequency while the low frequency of adhesive bond was found to be on the order of 1 rad / sec. Thus, the frequency range for use according to the invention is 1 to 100 rad / sec.

It is believed that the bonding characteristics of the adhesive are most appropriately selected at human body temperature. The topical adhesives according to the present invention are used directly on the skin and those skilled in the art will select adhesive compositions having low specific heat capacity (eg preferably less than 4 J / g / K), so that the actual temperature of the topical adhesives is It may very quickly reach 37 ° C. or be warmed by humans prior to application.

To provide good bonding conditions at a frequency of about 1 rad / sec, the absolute value of the elastic modulus should not be too high, otherwise the adhesive will be too hard and cannot be bonded or molded immediately to the surface to be bonded. In addition, it is important to have a low G "absolute value to have good adhesion, especially useful when using sanitary convection materials that are flexible and can be properly adhered to the skin and products that are frequently detached and then attached or replaced.

_{G '37 (1rad / sec)} / G "37 (1rad / sec) ratio, it is important that the two values at the time of adhesion to the skin for sure to balance the same time, G' absolute change in the ₃₇ frequencies that are considered should be restricted in range. Thus, △ G _{'37 (i.e., G' 37 (100rad / sec} ) -G '37 (1rad / sec)) / G' 37 (1rad / sec) is a value of the ratio with the passage of time continues to be less to discomfort or removal / pirate layer when discomfort to the resulting standing attachment of an adhesive for topical safely without a, which may be represented as an absolute value written because keep △ G _'37 is less than a certain value, that is , the dynamic aspects of the elastic and the viscous module are both firmly adhered to surely maintain the relationship that is easily removed without pain _{(G '37 (100rad / sec} ) -G "37 (100rad / sec)) / (G' 37 (1rad / sec) -G " ₃₇ (1rad / sec)) ratio should be large enough.

Finally, those skilled in the art recognize that the glass transition temperature (T _g ), specific heat capacity and specific thermal conductivity of the adhesive composition are useful parameters to more fully define useful topical adhesive groups.

The following features must be met.

G ′ ₃₇ (1 rad / sec) is in the range 1500 to 20000 Pa, preferably in the range 1500 to 15000 Pa, most preferably in the range 3000 to 10000 Pa.

G ″ ₃₇ (1 rad / sec) is in the range of 100 to 15000 Pa, preferably in the range of 100 to 10000 Pa, most preferably in the range of 300 to 5000 Pa.

_{G '37 (1rad / sec)} / G "37 (1rad / sec) ratio is in the range of 3 to 30 range.

And _{(G '37 (100rad / sec} ) -G "37 (100rad / sec)) / (G' 37 (1rad / sec) -G" 37 (1rad / sec)) ratio of 0.5 or more, preferably 0.7 to 3 range, most preferably 1 to 1.8.

ΔG ′ ₃₇ / G ′ ₃₇ (1 rad / sec) ratio is 1.5 or less and preferably 1 or less and most preferably 0.8 or less, or ΔG ′ ₃₇ is 10000 Pa or less and preferably less than 5000 Pa and most preferably It is either less than 2000Pa, or _{△ G '37 / G' 37} (1rad / sec) ratio is 1.5 or less, and preferably 1 or less and most preferably 0.8 or less at the same time △ G _'37 is 10000Pa or less and preferably less than 5000Pa And most preferably less than 2000 Pa.

The value of at least the ΔG ′ ₃₇ / G ″ ₃₇ ratio for frequencies ranging from 1 to 100 rad / sec is preferably at least 3.3, more preferably at least 5, most preferably at least 10 and at a frequency interval of about 30 , Preferably no more than 20.

The fluid aspect may also be related to the glass transition temperature (T _g ) values. For topical adhesives according to the invention the glass transition temperature should preferably be below -15 ° C, more preferably below -20 ° C and most preferably below -25 ° C.

Flowability aspects and tolerability of topical adhesives may also be related to specific heat capacity. Preferably the specific heat capacity of the topical adhesive is less than 4J / g / K, more preferably less than 3J / g / K, most preferably less than 2J / g / K.

The flowability and tolerance of topical adhesives may also be related to the specific thermal conductivity of the adhesive. Preferably the specific thermal conductivity is as low as possible (except for energy transfer products, where larger values are more preferred), more preferably 1 to 0.1 W / m / K, most preferably 0.6 to 0.1 W / m / K. .

Chemical and Compositional Characteristics of Topical Adhesives

The following formulation criteria are used to provide a preferred topical adhesive composition that meets the requirements of the fluid and physical characteristics of the topical adhesive. It should be noted that most of the compositions useful as topical adhesives have a substantially gel-like structure and are preferably gels. This is derived from the following facts.

(1) The main component is a plasticizer which is a liquid substance at room temperature.

(2) Macromolecules or polymerizable components are present in small amounts relative to the plasticizer. They form, in a preferred embodiment, three-dimensional networks generated by physical or chemical bonds between molecules. Particularly useful are the physical bonds present in systems containing block thermoplastic elastomers.

Typical compositions possible for topical adhesives can be divided into the following three groups depending on the nature of the main ingredient (typically liquid plasticizer (s)).

(1) A hydrophobic (lipophilic) composition wherein the plasticizer is typically an oil derived from a vegetable or mineral source or a blend thereof and the polymer is generally a synthetic polymer, preferably an elastomer, which can be dissolved or swelled in the oil (s).

(2) Mixed-phase compositions wherever possible, in both plasticizers and polymers, both hydrophobic and hydrophilic components form two or more separate phases. In this case the emulsifier / surfactant is preferably present in an amount suitable to form a stable emulsion between incompatible phases. In the case of topical adhesives according to the invention, it is preferred that they consist primarily of hydrophobic components compared to hydrophilic components;

(3) Hydrophilic compositions, typically wherein the plasticizer is water / glycerol / glycol and / or mixtures thereof and the like and the polymer phase originates from a synthetic (eg polyacrylic) or natural (eg natural gum) source or mixtures thereof.

Unlike the prior art and medicinal field described above, it is emphasized that hydrophobic (lipophilic) and mixed phase compositions 1) and 2) above are preferred for use in the present invention while hydrophilic compositions are undesirable.

This depends in part on technical reasons in that many hydrophilic compositions used in the medical field exhibit too low elastic properties and adhesion for use in the present invention. Another reason for favoring hydrophobic or mixed phase compositions is that the application of the present invention, particularly in the field of sanitary napkins, involves the possibility of contact with the liquid to which the topical adhesive is to be absorbed. Since liquids are all common aqueous types, contact with hydrophilic topical adhesives can result in some absorption of body fluids into topical adhesives.

This results in a change in the flow characteristics, resulting in a change in the action of the topical adhesive, resulting in an unsanitary appearance.

In addition, contrary to typical expectations when applied to human skin, hydrophilic topical adhesives are likely to be perceived as cold and moist. Another problem arises, in particular because topical adhesives comprising water as plasticizers tend to be dry unless they are sealed in an impermeable package.

Particularly preferred compositions belonging to the first group of hydrophobic compositions have been found to comprise the following compounds:

-First copolymer, polystyrene-block-poly (ethylene-lan-butylene) -block-polystyrene having a content of more than 70% by weight, more than 25% by weight of styrene, and a molecular weight of more than 60,000; 15% by weight, preferably 5 to 10% by weight,

As a second copolymer, from 0 to 9% by weight of polystyrene-block- (polyethylene-lan-butylene) -block-polystyrene having a triblock content of less than 70% by weight, a styrene content of less than 20% by weight and a molecular weight of less than 60,000, Preferably 0 to 6% by weight.

The polystyrene-block- (polyethylene-lan-butylene) -block-polystyrene, which is both the first and second copolymers, is preferably styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-ethylene-butylene-styrene, Styrene-block-copolymers of the styrene-ethylene-propylene-styrene type.

As plastic compound, 20 to 95% by weight, preferably 30 to 60% by weight, of oil having a paraffin fraction of more than 50% by weight and an aromatic fraction of less than 5% by weight.

The oil is selected from the group consisting of natural and synthetic oils, such as vegetable oils, mineral oils or mixtures thereof.

0 to 50% by weight, preferably 30 to 50% by weight of hydrogenated cycloaliphatic adhesive resin. The resin should have a major range tailored to the glass transition temperature of the system containing the synthetic polymer and be compatible with the rubbery blocks of the styrenic copolymer.

0 to 10% by weight of additives.

Such additives may be materials for promoting and stabilizing gels and gelling processes of hydrophobic liquid plasticizers. These include fatty acids having 8 to 22 carbon atoms, their metal salts and their polyoxo-derivatives; Lanolin derivatives; Silica; Bentonite, montmorillonite and derivatives thereof; Polyamides; Wax or mixtures thereof. Conventional additives known in the art may be included such as preservatives, antioxidants, UV blockers, pigments, mineral fillers, rheology modifiers and the like. Preferably the antioxidant is included in an amount of 0.3 to 1% by weight, the gel stabilizer is included in an amount of 0 to 1% by weight.

Application of topical adhesives

Absorbent articles in which topical adhesives according to a preferred embodiment of the invention may be used may be prepared by any of the methods common in the art. Since the adhesive can be provided by any known technique commonly used in other adhesives, application of the adhesive to the topsheet of the absorbent article, more generally the skin facing side, poses a significant problem for those skilled in the art. It should not be. The total area applied by the lipophilic topical adhesive on the skin or wearer facing surface of the absorbent article depends on the intended use. The preservation of the adhesive should be no more than 80%, preferably 30-60% of the wearer facing surface. In a preferred embodiment of the absorbent article, the total area of the skin facing surface applied with the topical adhesive should be 20% or less, preferably 10% or less. Preferably, the adhesive is preferably present on a portion of the film that is close to the perimeter of the absorbent article and in the case of a film topsheet (or when the backsheet is folded on the topsheet) and not permeable to the liquid.

If possible, the absorbent article also provides breathability because it is at least water vapor permeable, preferably air permeable to prevent stiffening. If breathability is not supported by a topical adhesive, breathability may be limited to areas of absorbent product to which the adhesive is not applied.

Topical adhesives on absorbent articles are preferably protected prior to use. The protection may be achieved by a release liner that is easily peeled off against selected topical adhesives such as silicone or surfactant treated paper.

In a preferred embodiment, the present invention can be advantageously used on disposable absorbent articles applied directly to the user's skin. Absorbent products are generally absorbent to body fluids, prevent user clothing from being contaminated, comfortable to the user, and easy to manufacture and package. Disposable absorbent articles are described as follows for sanitary napkins or menstrual articles, but pantyliners, adult urinary incontinence products or sweat pads are also included in the term disposable absorbent articles. As used herein, the term "physiological zone" refers to a product that is worn by a woman adjacent to the vulva to absorb and contain various body fluids secreted from the body (e.g. vaginal discharge, menstrual blood and / or urine) and to be discarded after a single use. Say. The disposable absorbent article is preferably thin and more preferably 1 to 5 mm thick and is substantially flat or preformed before use.

The term "connection" or "attachment" as used herein refers to a form in which the first member is directly connected to the second member, and the first member is connected by connecting the first member to the intermediate member and connecting the intermediate member to the second member. And indirectly connected to the second member.

In a preferred embodiment, the sanitary napkin of the present invention comprises a liquid permeable topsheet, a liquid impermeable backsheet connected to the topsheet, and an absorbent core between the topsheet and the backsheet. The sanitary napkin has two main surfaces: a body contact surface or a wearer facing surface to which a topical adhesive is applied, and a garment facing surface or a garment contact surface.

The topsheet has a compliant, supple feel and is non-irritating to the wearer's skin. The topsheet may also have an elastic feature in which some of the topsheet or all of its extensions are stretched in one or two directions. The topsheet is also fluid permeable to allow fluid (eg, menstrual blood and / or urine) to pass through it easily.

Preferred topsheets for use in the present invention are selected from the group consisting of high loft nonwoven sheets and perforated molded film topsheets. Perforated molded films are particularly preferred for topsheets because they are permeable to body secretions but are nonabsorbable and have a low tendency to rewet the wearer's skin by refluxing the fluid. Thus, the surface of the molded film in contact with the wearer remains dry, thus reducing body contamination and making the wearer feel more comfortable. Suitable molded films are described in US Pat. No. 3,929,135, US Pat. No. 4,324,246, US Pat. No. 4,342,314, US Pat. No. 4,463,045 and US Pat. No. 5,006,394. Particularly preferred microperforated film topsheets are described in US Pat. No. 4,609,518 and US Pat. No. 4,629,643. Preferred topsheets for the present invention include the molded film described in one or both of the above patents, and are described as "DRI-EWAVE" by The Procter & Gamble Company, Cincinnati, Ohio. Is commercially available.

Topical adhesives are best suited on topsheets having liquid transfer passages oriented such that the liquid transfer passages are not evenly distributed and only a portion of the topsheet is permeable to the liquid at the center and impermeable to the perimeter. Used.

Another alternative is called hybrid topsheets incorporating fibrous and filmlike structures, and particularly useful embodiments of hybrid topsheets are described in PCT Publications WO 93/09744, WO 93/11725 or WO 93/11726. .

When referred to as topsheet, a multilayer structure or a single layer structure is considered. The aforementioned hybrid topsheet is also contemplated as a multilayer design as described above, or other multilayer topsheets such as primary and secondary topsheet designs.

The absorbent core may also include multiple layers and provide fluid storage and distribution functions.

The absorbent core is positioned in fluid communication with the topsheet and is typically below the topsheet. The core may comprise any general absorbent material or combinations thereof. The core preferably comprises an absorbent gelling material generally referred to as a "hydrogel", "superabsorbent", "hydrocolloid" material in combination with a suitable carrier.

Absorbent gelling materials suitable for use herein most often include polymeric gelling materials that are substantially water insoluble and slightly crosslinked and partially neutralized. Such materials form hydrogels upon contact with water. Such polymerizable materials can be prepared from polymerizable unsaturated acid-containing monomers such as acrylic acid, which are well known in the art.

Suitable carriers include materials conventionally used in absorbent structures, such as natural, modified or synthetic fibers, specifically modified or unmodified cellulose fibers in fluff and / or tissue form. Suitable carriers may be used with the absorbent gelling material, but they may be used alone or in combination. With regard to sanitary napkins / pantyliners, tissues or tissue laminates are most preferred.

Particularly useful embodiments of the core in the use of the present invention include bilayer tissue laminates formed by folding tissue. These layers can be connected to each other. Absorbent gelling materials or other optional materials may be included between the layers.

The absorbent core may comprise optional components generally present in the absorbent web, such as odor inhibitors, in particular suitable zeolites.

The backsheet is absorbed by the absorbent core so that the contained secretions do not wet the materials that come into contact with the absorbent product, such as underpants, pants, pajamas and undergarments. The backsheet is preferably made from a plastic film which is impermeable to liquids (eg menstrual blood and / or urine) and is generally thin.

The backsheet typically extends throughout the absorbent core and extends to the topsheet and then folded around the absorbent core to form part of the topsheet. As such, the topsheet form described in US Pat. No. 4,342,314, line 16, lines 47 to 62 can be obtained without the need to selectively perforate the top sheet.

Example 1

10% by weight of Kraton G-1651, a styrene / ethylene-butylene / styrene block copolymer containing 33% by weight of styrene and available from Shell Co., Witco Co. A useful oil-based composition according to the invention in physiology was prepared using 49 wt% of Kaydol, a paraffinic mineral oil available from.

In addition, the composition contained 40% by weight of the adhesive resin. The adhesive resin was Escorez 5300, a hydrogenation resin available from Exxon Co.

0.7% by weight of Magnesium Stearate, available from Carlo Erba S. p. A., was used as an auxiliary gelling agent for the oil.

Irganox 1010, an antioxidant available from Ciba-Geigy, was added in an amount of 0.3% by weight.

Thus, the final formulation included 10.0 wt.% Kraton G-1651, 49.0 wt.% Kaidol, 40.0 wt.% Escorez 5300, 0.7 wt.% Magnesium stearate and 0.3 wt.% Irganox 1010.

The composition exhibited the following fluidity at 37 ° C .:

a) G _'37 = modulus of elasticity of at 1rad / sec 7038Pa;

b) G " ₃₇ = 487 Pa with viscous modulus at 1 rad / sec;

c) the ratio of the elastic and viscous modulus at _{1rad / sec G '37 / G} "37 = 14.45;

_{d) (G '37 (100rad} / sec) -G "37 (100rad / sec)) / (G' 37 (1rad / sec) -G" 37 (1rad / sec)) ratio = 1.11;

e) ΔG ′ ₃₇ / G ′ ₃₇ (1 rad / sec) ratio = 0.291 (ΔG ′ ₃₇ = 2051 Pa).

The combination has been tried in physiology and has been found to be comfortable at the time of initial application and to be comfortable when detached from sensitive skin containing hair.

Comparative Example

7.1 wt% of Kraton G-1651, a styrene / ethylene-butylene / styrene block copolymer containing 33 wt% of styrene, available from Shell Company, and 41.9 wt% of kaidol, a paraffinic mineral oil available from Witco Company. To prepare a comparative oil-based composition.

In addition, the composition contained 704 parts of adhesive resin per 100 parts of craton polymer. The adhesive resin was Regalerez 3102, a carbonization resin available from Hercules Co.

0.7% by weight of magnesium stearate, available from Carlo Erva S.P.A, was used as an auxiliary gelling agent for the oil.

Irganox 1010, an antioxidant available from Ciba-Geigy, was added in an amount of 0.3% by weight.

Thus, the final formulation included 7.1 wt% of Kraton G-1651, 41.9 wt% of chidol, 50.0 wt% of Regalez 3102, 0.7 wt% of magnesium stearate and 0.3 wt% of Irganox 1010.

The composition exhibited the following fluidity at 37 ° C .:

a) G _'37 = modulus of elasticity of at 1rad / sec 3059Pa;

b) G " ₃₇ = 1208 Pa with viscous modulus at 1 rad / sec;

c) the ratio of the elastic and viscous modulus at _{1rad / sec G '37 / G} "37 = 2.53;

_{d) (G '37 (100rad} / sec) -G "37 (100rad / sec)) / (G' 37 (1rad / sec) -G" 37 (1rad / sec)) ratio = -2.87;

e) ΔG ′ ₃₇ / G ′ ₃₇ (1 rad / sec) ratio = 3.944 (ΔG ′ ₃₇ = 12064.7 Pa).

The formulation proved to be very inconvenient to detach from the forearm skin. It could not be applied to sensitive skin containing body hair.

Claims (5)

As the first copolymer, polystyrene-block-poly (ethylene-lan-butylene) -block-polystyrene having a content of more than 70% by weight, more than 25% by weight of styrene, and a molecular weight of more than 60,000. Weight percent, preferably 5 to 10 weight percent, As the second copolymer, 0 to 9% by weight of polystyrene-block- (polyethylene-lan-butylene) -block-polystyrene having a ternary block content of less than 70% by weight, a styrene content of less than 20% by weight and a molecular weight of less than 60,000, preferably Preferably 0 to 6% by weight, As a plastic compound, 20 to 95% by weight of oil, preferably 30 to 60% by weight, having more than 50% by weight of paraffin fraction and less than 5% by weight of aromatic fraction, 0-50 wt%, preferably 30-50 wt% of a hydrogenated alicyclic adhesive resin, 0 to 10% by weight of an additive selected from the group consisting of antioxidants and gel stabilizers, preferably comprising 0.3 to 1% by weight of antioxidants and 0 to 1% by weight of gel stabilizers, A lipophilic topical adhesive for attaching any product to the skin. The method of claim 1, The first copolymer and the second copolymer, polystyrene-block- (polyethylene-lan-butylene) -block-polystyrene, are respectively styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-ethylene-butylene-styrene, styrene- Selected from the group consisting of styrene-block-copolymers of the ethylene-propylene-styrene type, The oil is selected from natural or synthetic oils selected from the group consisting of vegetable oils, mineral oils and mixtures thereof. Additives include fatty acids having 8 to 22 carbon atoms, metal salts thereof, and polyoxo-derivatives thereof; Lanolin derivatives; Silica; Bentonite, montmorillonite and derivatives thereof; A lipophilic topical adhesive selected from the group consisting of polyamides, waxes and mixtures thereof. The method according to claim 1 or 2, A lipophilic topical adhesive having a glass transition temperature of less than -15 ° C, preferably less than -20 ° C, most preferably less than -25 ° C. The method according to any one of claims 1 to 3, A lipophilic topical adhesive wherein said product is a disposable absorbent product. Use of a lipophilic topical adhesive according to any one of claims 1 to 4 on a sanitary napkin or pantiliner.