DE2118477A1 - Toothpastes - Google Patents

Description

DR. ING. A. VAN DERWERTH DR. FRANZ LEDERER

2t HAMBURG 90 '8 MÖNCHEN 80

WILSTORFEH STR. 33 - TEL. (0411 »77 0 * 61 LUCILE-GRAHN-STR. S3 - TIL. 10»! Il 44 0 * 46

Case J 176 / I76a

Munich, April 8, 1971 L / My

Applicant: Unilever N.V., Museumpark 1, Rotterdam, Netherlands

Toothpastes

The invention relates to toothpastes.

Most toothpastes contain a proportion of water, the liquid phase being a mixture of humectants and there is water. Glycerin and sorbitol are the most common humectants, although others are occasionally used will.

Chloroform is a component that is often added to toothpastes to improve the taste. It will be common in an amount between 0.5 to 4.0 wt. # added.

However, the incorporation of chloroform can cause corrosion of the aluminum tubes, which is the most common and

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The hottest material for toothpaste packaging is «It has been suggested to solve this corrosion problem by that Use of relatively high levels of glycerin in the liquid phase of the toothpaste to weaken. However the use of high glycerol contents leads to products that are burdened by high material costs, fibrous Have breakage and are slow to disperse in the mouth. The problem of tube corrosion due to chloroform arises, if the water in the toothpaste is more than 20% by weight of the liquid sigen phase is present. The occurrence of corrosion is also particularly noticeable with chloroform contents of about 1% by weight of the toothpaste. The problem of corrosion due to the chloroform content has been known to toothpaste manufacturers for a long time.

It has now been found that the corrosion of aluminum due to chloroform is considerable in the case of toothpastes with a content of glycerine as a moisturizing agent Incorporation of urea, biuret, gelatin or benzoic acid or a water soluble salt of benzoic acid or one Mixture of these substances in the product can be reduced.

Accordingly, the invention provides a toothpaste which contains glycerin, water and chloroform and has a reduced tendency to Has corrosion of aluminum and which acts as a corrosion inhibitor urea, biuret, gelatin or benzoic acid or a water-soluble salt of benzoic acid is incorporated.

The one required for a corrosion-inhibiting effect The content of urea, biuret, gelatin, benzoic acid or a benzoic acid salt in the toothpaste can be determined by experiment will. The amount required is related to the amount of water in the toothpaste. Increasing amounts of inhibitor are required with the presence of larger amounts of water in the toothpaste. In normal practice, the

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Amount of water vary from about 25 to about 60 wt.% Of the liquid phase of the toothpaste. Furthermore, higher levels of chloroform, in the range of -0.5 to $ 4.0, generally tend to cause more corrosion. However, as has been found for a particular combination of levels of water and chloroform, it is merely a matter of simple experimentation to determine what level of the relevant suitable inhibitor is required to effect / prevent corrosion. An anti-corrosive effect is sometimes achieved with an amount of urea as low as 0.1% by weight of the toothpaste, although generally an amount of at least 0.5% by weight and in the range of 0.5 to 2% by weight will be desirable . The chemically related compound biuret does not appear to be quite as effective as urea when used in equal amounts by weight, and biuret is therefore used in an amount of at least 0.5% by weight of the toothpaste, preferably in an amount of 1 to 2% by weight. ^, applied.

When using gelatin as a corrosion inhibitor, this material is used in an amount of at least 0.1% by weight of toothpaste, and preferably used in the range of $ 0.5 to $ 2. Benzoic acid and its water-soluble salts are preferably in an amount of at least 0.5 wt. ^ of the toothpaste, and preferably in an amount of 1 to 5 wt. # used

There is no benefit in using more inhibitor than is necessary to obtain the required reduction in corrosion, apply. The amounts of corrosion inhibitor required are unlikely to ever reach $ 10 and are becoming common Do not exceed 5% by weight of the toothpaste.

In addition to the corrosion inhibitor, the toothpaste according to the invention contains the usual ingredients in the usual proportions.

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keep. Thus, a tooth paste of the invention in addition to dom corrosion inhibitor is preferably 15 to 40 wt. ^ Glycerol, 30 to 60 wt. 'Ρ a cleaning abrasive and active substance, 1 to 2.5 wt. ^C / o of a surface. active agent, 0.5 to 4 wt. ^ b chloroform and the usual small amounts of binder, flavoring and sweetener, the remainder water, the latter is usually present in an amount of about 8 to 30 wt.

The following experiments illustrate the invention, the percentages being by weight.

Five basic toothpastes were made using the following approaches:

Stock ex Toothpaste: chalk 50 I. % Amount 00 III 00 IV V 50 Alpha alumina tri-
hydrate .00 II 6th Dicalcium phosphate dihydrate 55. 50 Anhydrous dicalcium
phosphate 55. 42.50 42, precipitated silica 4th 50 50 6.50 Titanium dioxide .00 00 00 Glycerin 25th 0. .00 .00 0. 20th 28.00 28 27

Sodium carboxymethyl

cellulose 0.60 0.60 0.75 0.75 Ο.75

Sodium Lauryl Sulphate 1.50 1.50 I.50 I.50 I.50

Saccharin 0.15 O.I5 O.I5 O.I5 O.I5 -

Sodium dihydrogen ortho-

phosphate 0.40 0.40

Flavor 1.00 1.00 1.00. 1.00 1.00

Chloroform * <from $ 2.5 to 3 O ^?

Water <: to 100 ψ

*. The amount of chloroform varied due to the volatility of the chloroform. £ 10,984 / £ 183 3

Other toothpastes were made in accordance with the invention by replacement part of the abrasive produced the corrosion inhibitor.

All toothpastes were packaged in unpainted aluminum tubes and tested for corrosion using one or more of the following test methods.

Test method A

Six tubes of the toothpaste to be tested were stored at 50 ° C. and 65 ° C. for a period of up to 6 months and one tube of each test product at each temperature was opened every month and the inner walls were checked for corrosion.

Test method B

21 6 and 72 tubes of the test product were stored at J50 ° C and 65 ⁰ C and di checked for outward signs of corrosion on tubes perforation of the tube in different time intervals. The percentage of the number of tubes stored showing signs of corrosion was determined for each app test.

Test method C

Between 12 and 24 tubes of the test toothpaste were stored at 65 C and at monthly intervals for external signs of a Corrosion tested. The percentage of the number stored Tubes showing outward signs of corrosion were determined in each test.

The results obtained are shown in the tables below.

The results obtained with test methods A and B, which explain the effectiveness of urea, follow in the tables 1 or 2.

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^C P urine
material I. • Table 1 3 months 6 months tooth
paste 0 # Urine
material perforation perforation I. 0.1 easy easy 1 Extent of corrosion after storage at 65 ° C
while very easy easy 2 1 month no no 5 moderate no no Ö easy perforation perforation II 1 no no no 2 no no . no 0 no perforation perforation III 2 moderate no no 0 no strong perforation IV 2 no no no 0 perforation perforation perforation V 1 no no no easy no Percent perforated tubes after one
Storage for 12 months tooth
paste perforation no Table 2

at 50 ⁰ C

at 65 C

I. 0 1 - 2 60 86 II O 0 Q 2

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The box don Teslniotliorlen B and C received. Results which explain the effectiveness of biuret as a corrosion inhibitor, Γοΐ, 'τοη in Tables 3.hzw. 4th

Biuret Table 3 Number of weeks of the
Storage at 65 C Zalin-
past 0 * f> perforated
Tubes 14th I. 2 63 14th 3 21st 14th 14th Biuret Table 4 Storage time
(Months) tooth
paste 0 $ perforated
Tubes. 3 I. 2 82 3 4th 13th 3 0 0 3 II 1 11 3 2 0 3 0 0 2 III 2 89 2 4th 0 2 0 0 2 IV 2 37 2 4th 5 2 0

The results obtained with test methods B and C, which illustrate the effectiveness of gelatin as a corrosion inhibitor, follow in Tables 5 and 6, respectively.

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Table 5

Tooth- ^ o
paste gelatin

perforated tubes. Storage of

6 months ',

at 50 ° C

at 65 C

O
2

93 25

paste gelatin

Table 6

perforated tubes after storage for 6 months

0
0.5

93

18th

Ii

7.0 1.5 2.0

53

none none none

ITI

0
2.0

88 * none

Result after 2 months

The results obtained by test methods A ₁ B and C, which illustrate the effectiveness of sodium benzoate as a corrosion inhibitor, follow in Tables 7, 8 and 9, respectively.

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Table 7

Tooth ',' sodium paste Benzoate corrosion emission after storage at 50 C during

month

3 months

6 months

IV

0
2

easy easy very easy none

easy very easy

0
2

slight perforation perforation slight, very slight, none

Table 8

Dental io sodium paste benzoate perforated tubes after storage for 6 months

at 50 C

at 65 C

02 93

TI

0 2 1.5

53 31

Table 9

Toothpaste

Sodium benzoate 'fo perforated tubes after storage for 6 months

0 0.5 93 16

III

88 20

* Notice after 2 months

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The results obtained by test method C, which explain the effectiveness of benzoic acid and a large number of water-soluble salts of benzoic acid., As corrosion inhibitors, follow in Table 10. The results relate to the incorporation of the inhibitor in an amount of 2 % the toothpaste

cation

Tabel

^ P tubes showing signs of corrosion after 6 months of storage

at 50 C at 65 C O 24 5 11 12th 42 5 5 0 0 0 5 0 17th 0 0. 0 0 0 37 52 93

ir Li ¹

N / A

NH ₂ Mg

Ca Sr Zn

2 +

2 + 2 +

2 +

3 +

Alkeine inhibitor

While urea was already suggested in toothpastes and incorporating biuret as therapeutic agents, gelatin as a binder and sodium benzoate as a preservative, The use of these substances as corrosion inhibitors in toothpastes containing chloroform is new and one Enrichment of technology and thus also inventive.

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Claims (6)

Claims 1. Zalin paste, which contains glycerin, water and chloroform and would have a corrosive effect on aluminum, characterized by a content of urea, biuret, Gelatin, benzoic acid or a water-soluble salt of benzoic acid as a corrosion inhibitor. 2. Toothpaste according to claim 1, characterized by a Content of 0.1 to 5% by weight of urea as a corrosion inhibitor. 3. Toothpaste according to claim 1, characterized by a content of 0.5 to 5 wt. ^ Of biuret as a corrosion inhibitor. H. Toothpaste according to Claim 1, characterized by a gelatine content of 0.1 to 5% by weight as a corrosion inhibitor. 5. Toothpaste according to claim 1, characterized by a content of 0.5 to 5 wt. ¹ Jo of benzoic acid or a salt thereof as a corrosion inhibitor. 6. Use of urea, biuret, gelatin, benzoic acid or a water-soluble salt of benzoic acid as a corrosion inhibitor in toothpastes containing glycerine, water and chloroform. 1098 4 4/1833