WO1994017135A1

WO1994017135A1 - Solid sun-ray filtering means for optimum suntan

Info

Publication number: WO1994017135A1
Application number: PCT/DE1994/000077
Authority: WO
Inventors: Maximilian F. Mutzhas
Original assignee: Mutzhas, Irmgard
Priority date: 1993-01-29
Filing date: 1994-01-28
Publication date: 1994-08-04
Also published as: CA2154893A1; AU5879594A; DE9301250U1; EP0681596A1

Abstract

A solid sun-ray filtering means for optimum suntan is disclosed, in particular shaped as slabs, foils, nonwovens, fabrics or lacquers for parasols, tilts, tents, roofings, shelters, canopies, awnings, articles of clothing, huts, caps, visors or the like for human beings, as well as shelters and roofings for animals having thin fur or feathers. In order to achieve an adequate protection against acute skin lesions, at the same time as a durable pigmentation, the erythrem factor equals at least 15 and maximum 40, and the pigmentation factor at least 4 and maximum 6.

Description

Solid-state sunscreen for optimal skin tanning

The invention relates to a solid-state sunscreen for optimal skin tanning, in particular in the form of plates, foils, nonwovens, fabrics or lacquers.

Reports of an increasing number of chronic skin damage, mostly associated with the dermatological consequences of the ozone hole, lead to the fact that sunscreens with a high sun protection factor are being used to an increasing extent.

High sun protection factors for topical sunscreens can only be achieved with high absorber concentrations. At these concentrations, the absorbers in the peripheral blood circulation can be detected after a relatively short time. Because of the possible local and systemic toxic effects, topical sunscreens with high absorber concentrations are not without problems.

A sensible way out is to use a solid-state sunscreen, the absorbers of which do not cause any toxic reactions even when in contact with the skin. The absorbers are therefore embedded in plastic, which is in the form of plates, foils, nonwovens, fabrics or lacquers. This solution has been used in various ways so far, the light protection factor (erythema factor) and the direct pigmentation being taken into account as criteria for the protective effect.

However, based on extensive photobiological experiments and calculations, it was found that direct pigmentation, which usually fades after several hours, is not a reasonable criterion for permanent pigmentation. The same applies to information that only relates to spectral transmission without the associated photobiological effects.

The invention solves the problem as a Solid-state sunscreen must be obtained in order to achieve a corresponding protective effect against acute (and chronic) skin damage on the one hand and on the other hand to obtain permanent pigmentation.

The object is achieved in such a way that the sun protection factor (erythema factor) for normal skin types is at least 15, the attenuation factor for permanent pigmentation (pigmentation factor) is at most 6.

This makes it possible to receive less than a threshold dose for erythema (= minimum erythema dose MED) and, at the same time, more than one threshold dose for permanent pigmentation (= minimum pigmentation dose MTD) in the time from 9 a.m. to 3 p.m. local time. to obtain. To be on the safe side, it was assumed that the person under radiation did not turn around during these 6 hours (in which about 75% of the erythema-effective daily dose is irradiated), so that the entire erythema-effective dose acts on one half of the body. For the permanent pigmentation it was realistically assumed that this radiation is distributed evenly over both halves of the body.

The solid-state sunscreen delays desired and undesired photobiological reactions. This factor (F _biol ) by which the reaction is delayed is defined as follows:

λ ₂

JE (λ) _e • S (λ) biol dλ λ l biül λ ₂

/ E (λ) _e • s (λ) _biol • τ (λ) • dλ λ

mean λ- lower wavelength limit λ ₂ upper wavelength limit

E (λ) _e spectral irradiance of the global radiation τ (λ) spectral transmission of the

Solid-state sunscreen s (λ) _b i _o i relative spectral sensitivity of human

Skin for the photobiological reaction

the following indices mean UV-induced erythema formation in people with normal skin reaction pp UV-induced permanent pigmentation in people with normal skin reaction ca UV-induced skin cancer el UV-induced skin aging pi UV-induced direct pigmentation (immediate pig ent darkening) in humans with normal

Skin reaction.

The important parameters for this are:

the erythema factor

400 nm

J E (λ), s (λ), dλ 290 nm

Fer =

400 nm j E (λ) _e • ε (λ) _er • τ (λ) • dλ 290 nm

the pigmentation factor

400 nm

JE (λ) _e • s (λ) _pD • dλ

290 nm

_{Fn =} 400 nm

/ E (λ) _e • s (λ) _pp • τ (λ) • dλ 290 nm

the average transmission from 290 - 330 nm 330 nm

_. τ (λ) • dλ 290 nm τ, =

40

and the average transmission from 330 - 400 nm

400 nm

J τ (λ) • dλ 330 nm 70

The relationship between the parameters is as follows: 5.219 5.025 τ ₂ = -

F ^• " ^a pp F ^x cr

1.422 τ- = - 0.057 τ ₂

F

First, the desired factors are specified and the

Value for τ _{2 determined} with an accuracy of ± 0.035 and the value for τ- with an accuracy of ± 0.015.

It should be taken into account

F> 15

Values for τ ₂ > 0.9 and τ _: <0 are not real.

From this, the previously determined transmission values τ and τ ₂ can then be set experimentally or arithmetically using the Lambert-Beer's law by varying the concentration of the known absorbent materials and the type and thickness of the substrate.

As substrates for the solid-state sunscreen are in The following main plastics are used in the form of sheets, foils, nonwovens, fabrics and lacquer layers, which, depending on the modification, have sufficient transmission in the UV range: acrylonitrile methyl methacrylate (AMMA), cellulose acetobutyrate (CAB), ethylene tetrafluoroethylene (ETFE), ethylene vinyl acetate (EVA), polycarbonate (PC), polyethylene (PE, HDPE, LDPE), polyethylene terephtelate (PETP), polymethylene methacrylate (PMMA), polypropylene (PP), polytetrafluoroethylene (PTFE), polyurethane (PU), polyvinyl chloride (PVC).

The following materials are essentially used as absorbers for the solid-state sunscreen:

Benzophenones, benzotriazoles, compounds of salicylic, cinnamic and oxalic acid as well as compounds that result from modification of these substances.

The dyes for the solid-state sunscreen according to the invention must have a high transmission, especially in the range from 330 to 400 nm. These are mainly violet, red-violet and blue soluble dyes as well as organic and inorganic pigments.

The desired transmission values x _l and τ ₂ are determined using the following equations

a / b τ (λ) i, x = τ (λ) _{i) t}

τ (λ) = τ (λ) _iιS • τ (λ) _ifA • τ (λ) _ifF • R _f

τ (λ) i _pure spectral transmission R _f reflection _{factor of} the substrate τ (λ) _{iιb pure} spectral transmission with known layer thickness or concentration τ (λ) _{iιX pure} spectral transmission at the desired layer thickness or concentration

^τ (λ) i, _s pure spectral transmission of the substrate

^τ (λ) i, _A pure spectral transmission of the absorber or

Absorber τ (λ) _{i (F} spectral pure transmission of the dye or

Dyes

The following table shows examples with different predefined erythema factors (F _βr ), combined with various predefined pigmentation factors (F _pp ) and the mean transmission values (τ _x ) determined in the spectral range 290 to 330 nm and the mean ones

Transmission values (τ ₂ ) in the spectral range 330 to 400 nm.

F _er F ^A pp τi τ ₂

10 6 0.121 0.367

10 5.5 0.117 0.446

10 5 0.111 0.541

10 4.5 0.105 0.657

10 4 0.096 0.802

10 3.7 0.091 0.900

15 6 0.064 0.534

15 5.5 0.060 0.614

15 5 0.054 0.709

15 4.5 0.048 0.825

15 4.2 0.044 0.900

20 6 0.036 0.619

20 5.5 0.031 0.698

20 5.0 0.026 0.793

20 4.5 0.020 0.900

25 6 0.019 0.669

25 5.5 0.014 0.748

25 5 0.009 0.843

25 4.7 0.005 0.900

30 6 0.007 0.702

30 5.5 0.003 0.781

30 5.0 <0 0.876

30 4.9 <0 0.900

35 6 0.006 0.726

35 5.5 <0 0.805 35 5.0 <0 0.900

40 6 <0 0.744

The following solid-state sunscreens were on the market before the filing date:

Brand Material Color TJ τ ₂ F _er F

Sunselect PVC Violet 0.144 0.632 7.9 4.1

Nylex PVC purple 0.038 0.510 21 7.0

Solmax PVC Purple 0.016 0.506 32 7.8

Sunselect PVC light blue 0.019 0.337 37 11

Sunselect PVC Pink 0.012 0.406 40 9.8

Sunselect PVC Blue 0.011 0.409 41 9.8

Mutzhas PE Yiolett 0.008 0.433 43 9.5

Mutzhas PMMA Violet <0.001 0.485 51 8.9

Procutis PVC Clear <0.001 0.476 52 9.1

Mutzhas PVC violet <0.001 0.398 63 11

Mutzhas PVC (grid) violet <0.001 0.366 68 12

Procutis PVC Purple <0.001 0.311 80 14

Procutis PVC Blue <0.001 0.256 97 17

None of these known solid state sunscreens meet the criteria of this invention.

The following solid-state sunscreens according to the invention were produced in-house:

Mutzhas PE Clear 0.060 0.614 15 5.5

Mutzhas PE violet 0.064 0.534 15 6.0

Mutzhas PVC Clear 0.054 0.709 15 5.0

Mutzhas PVC Purple 0.060 0.614 15 5.5

Mutzhas PMMA Clear 0.048 0.825 15 4.5

Mutzhas PMMA Violet 0.054 0.709 15 5.0

In a solid-state sunscreen according to the invention with an erythema factor F _er > 15 and a pigmentation factor

PP <6 shows:

The skin aging factor F _el is approximately 0.8 • F _er and the skin cancer factor F _ca is approximately 1.1 • F _er . The protection against this chronic skin damage is about the same as protection against acute skin damage sunburn. The threshold time for direct pigmentation, which fades again after a short time, is about half as long as the threshold time for permanent pigmentation. The permanent pigmentation can result in a body-specific erythema (protective) factor of a maximum of 8 with intensive expression.

If the erythema (protective) factor of the solid-state sunscreen is 15 or just above, a very high level of sun protection is achieved on the one hand, and on the other hand sufficient short-wave UV radiation in the range from 290 to 330 nm is transmitted to thicken the epidermis (light calluses ) to reach. A further erythema factor of a maximum of 4 can be achieved through this light calluses.

The solid-state sunscreen according to the invention can therefore be used to build up adequate erythema protection in the body without the skin being affected by excessive daily doses of damaging UV radiation.

Some practical examples are given below:

example 1

Three-layer film produced in the coextrusion process with the following structure

1. Top layer: 20 μm EVA 2. Core: 160 μm LDPE (which contains about 10% masterbatch, which contains the UV absorber and the purple dye).

3rd Top layer 20 μm EVA

FF _ee _ _r = = 1155

F _F , = 5.5 τ i = 0.06 ^τ . = 0.6 1 Example 2

Film manufactured in the calendering process with the following structure:

Thickness: 0.3mm

Substrate: colorless soft PVC in which the organic absorbers are dissolved. F _er = - 15

F _pp = 5.0 τ- = 0.05 τ ₂ = 0.71

Example 3

Cast PMMA sheet

Thickness: 5 mm

Substrate: PMMA stabilized in which the colorless organic absorbers are dissolved.

F _er = 15

F _PP = 4.5 τ, = 0.05 τ ₂ = 0.83

The solid-state sunscreen according to the invention is used, for example, in the following form:

Umbrellas, awnings, tents, roofs, canopies, canopies, awnings, clothing, hats, caps, visors for people as well as covers and canopies for animals with thin hair or feather clothing.

Claims

Expectations

1. Solid-state sunscreen, characterized by the following features: a) the erythema factor (F _er ) is at least 15 and at most 40 b) the pigmentation factor (F _pp ) is at least 4 and at most 6.

2. Solid-state sunscreen according to claim 1, characterized by a) an average transmission (τ ₂ ) in the spectral range from 330 to 400 nm

5,219 5,025

F ^■■ "pp F-- er b) an average transmission (x _γ ) in the spectral range from 290 to 330 nm from

1,422