NO152866B - CABLE PULL UNIT - Google Patents

Description

alcohol and its ester with a fatty acid, as well as its acetals.

However, only a sufficient sta-

bility when the formaldehyde does not contain special

equal to large amounts of methanol.

In the following test report, the stability

the head of such solutions indicated.

Comparison six example 1.

To a formaldehyde solution with a content

of 37.2 percent formaldehyde and 0.3 percent methanol to

add 0.005 percent pentaerythritol 0.02 percent polyethylene glycol stearate, 0.01 percent polyvinyl alcohol,

0.05% polyvinyl formal, a mixture of 0.02% hydroquinone and 0.005% polyethylene glycol stearate,

a mixture of 0.02% octanol and 0.05% pentaerythritol monoformal, a mixture of 0.05% sorbitan monopalmitate and 0.05% decanol or a mixture of 0.05% sorbitril methylene ether and 0.05% .heptanol and dissolve in the heat. An outcome

ling of paraformaldehyde takes place within 1 hour at 0°C.

Comparison six example 2.

To a formaldehyde solution with a content

of formaldehyde of 37.2 percent and 7 percent methanol, 0.0005 percent pentaerythritol stearate, 0.05 percent polyethylene glycol stearate, 0.01 percent polyvinyl alcohol

hol, a mixture of 0.02% 2-ethylhexanol and 0.0001% pentaerythritol stearate or a mixture of 0.02% hydroconone and 0.001% polyethylene glycol stearate and dissolve in the heat. Paraformalde hyde precipitation occurred within a day at

-H 6.6°C.

Comparison example 3.

To a formaldehyde solution with a content

of 45.2 percent formaldehyde and 1 percent methanol to

add 0.05 percent polyethylene glycol stearate, 0.0005

percent pentaerythritol dipropyl ether, 0.05 percent polyvinyl formal, 0.05 percent polyvinyl acetate, a mixture of 0.05 percent pentaerythritol monooleate, and 0.05 percent polyvinyl formal, a mixture of 0.02 percent hydro-

quinone, 0.02% 2-ethylhexanol and 0.0001% pentaerythritol stearate or a mixture of hydro-

quinone and 0.005 percent polyethylene glycol stearate. Paraformaldehyde precipitation occurs during 1

24 hours at 25°C.

Comparison example 4.

To a formaldehyde solution with a content of 50.2 percent formaldehyde and 1 percent methanol to

a mixture of 0.05 percent polyvinyl alcohol and 0.02 percent 2-ethylhexanol or a mixture of 0.05 percent sorbitol monopalmitate and 0.05 percent polyvinyl acetate is added and dissolved in the heat. The precipitation of paraformaldehyde occurs within 1 day at 40°C.

The present invention is thus based on

a stabilization of aqueous formaldehyde solution against excretion of paraformaldehyde, and the special

peculiar to the method according to the invention is that the solution is added

a) at least one guanamine of the general formula

in which R means a hydrocarbon residue, a methylolde-

rivate and/or the condensation product with an aldehyde and

b) at least one ester of a polyhydric alcohol with a higher fatty acid, an ether and acetal of

a polyhydric alcohol, a higher alcohol, hydro-

quinone, a polyvinyl alcohol, or an ester or acetal of a polyvinyl alcohol.

The guanamine compounds mentioned under a) are preferably used in an amount of 0.01 to 1 percent by weight and the compounds mentioned under b)

parts in an amount of 0.0001 to 0.1 percent by weight. A 30 to 55 percent formaldehyde solution or a solution containing up to 8 percent methanol by weight is preferably stabilized. The stabilization of aqueous formaldehyde solutions

nings with guanamines, e.g. formoguanamine, benzoguanamine, methylolated formoguanamine, methylolated mono- or dibenzoguanamine, acetoguanamine, N-phenyl-2,4-diamino-1,3,5-triazine, phenylacetoguanamine, tetrahydrobenzoguanamine, methylanilinopropioguanamine or phthalodiguanamine

min, is already known (Belgian patent specification 623 697).

Comparison tests show that the stability

of a 37 percent formaldehyde solution stabilized by guanamines is not fully sufficient.

For example stabilizes 0.08 percent benzoguanamine, which is apparently the best of the aforementioned guana-

miner, a 37 per cent formaldehyde solution with 0.3

percent methanol content for approximately 4 days at 0°C. The superiority of those according to the invention

Stabilizers used by nelsen in comparison to the known guanamines appear in particular from the following table:

Furthermore, according to the French patent document 1 228 672, an organic colloid, e.g. hydroxypropyl methyl cellulose, pectin, carrageenan, gelatin, sorbitan monolaurate and lipophilic polyoxyethylene lauryl ether.

The stability of a 37% formaldehyde solution when using these colloids is not mentioned in the patent description. However, after investigations, these compounds have no stabilizing effect on a 37% formaldehyde solution with less than 1% methanol when tested at 0°C.

As mentioned, the method according to the invention can be used for formaldehyde solutions with a formaldehyde content of up to 55% by weight. The method can be used for formaldehyde solutions with a very low methanol content, but is not limited to use for solutions with a low methanol content. When the method is used for solutions with a considerable methanol content, stability is achieved at lower temperatures than when storing solutions with a low methanol content.

With the method according to the invention, a formaldehyde solution with 37% formaldehyde and less than 1% methanol can be kept stable for more than 1 month at 0°C and a formaldehyde solution with 37% formaldehyde and 8% methanol for at least 1 week at -r- 6.6°C. A formaldehyde solution with 45% formaldehyde and less than 1% methanol can be kept stable for more than 1 month at 25°C.

As already indicated, a mixture of compounds from two groups is used to stabilize an aqueous formaldehyde solution.

Examples of compounds from group a) are benzoguanamine acetoguanamine, propioguanamine, butyroguanamine and their methyl derivatives including mono-, di-, tri- and tetramethylbl derivatives and a mixture of these, their condensates with an aldehyde, f e.g. formaldehyde, glyoxal, glutaraldehyde, adipicaldehyde.

Examples of compounds from group b) are hydroquinone, heptanol, octanol and decanol, polyvinyl alcohol, esters and acetals of polyvinyl alcohol, esters of pentaerythritol and polyethylene-1 glycol with palmitic, stearic or oleic acid, and ethers of pentaerythritol.

The stabilizers from group a) can be used in amounts between 0.1 and 1 per cent, preferably 0.05 to 0.2 per cent.

Depending on the structure of the compounds, the stabilizers from the second group are used in amounts between 0.1 and 0.0001 percent. As the stabilizer must be contained in the solution in a well-dissolved state, the mixture is preferably heated, e.g. to 40-60°C.

Should it return after warming up

*n undissolved residue, this is removed by filtration.

The following examples illustrate the invention.

The percentages in the examples refer to percentages by weight when not expressly stated otherwise.

Example 1.

To a formaldehyde solution with a content of 37.2% formaldehyde and 0.3% methanol is added 0.05% butyroguanamine, 0.05% benzoguanamine and 0.005% pentaerythritolate, a mixture with a high monooleate content, and the mixture is sufficiently dissolved in the heat. After cooling to room temperature and separation of undissolved by filtration, the solution can be kept stable without precipitation of paraformaldehyde at 0°C for more than 30 days.

Example 2.

To a formaldehyde solution with a content of 37.2% formaldehyde and 0.3% methanol, 0.05% butyroguanamine, 0.05% benzoguanamine and 0.02% polyethylene glycol stearate are added and the mixture is heated for solution. The undissolved substance is removed by filtration. The stored solution is resistant to the release of paraformaldehyde at 0°C for more than 30 days.

Example 3.

To a formaldehyde solution with a content of 37.2% formaldehyde and 0.3% methanol, 0.05% butyroguanamine, 0.05% benzoguanamine and 0.01% polyvinyl alcohol are added and the mixture is dissolved by heating. The solution is stable against precipitation of paraformaldehyde at 0°C for more than 30 days.

Example 4.

To a formaldehyde solution with a content of 37.2 percent formaldehyde and 0.3 percent methanol, 0.05 percent butyroguanamine, 0.05 percent benzoguanamine and. 0.05 percent polyvinyl formal and dissolves sufficiently in the heat. The mixture is cooled to room temperature and undissolved substance is removed by filtration. The solution is resistant to the release of paraformaldehyde at 0°C for more than 30 days.

Example 5.

To a formaldehyde solution with a content of 37.2% formaldehyde and 0.3% methanol, add 0.05% butyroguanamine, 0.05% benzoguanamine, 0.02% hydroquinone and 0.005% polyethylene glycol stearate and dissolve in the heat . No paraformaldehyde is released from the solution during storage at 0°C for more than 30 days.

Example 6.

To a formaldehyde solution with a content of 37.2% formaldehyde and 0.3% methanol is added 0.05% butyroguanamine, 0.05% benzoguanamine, 0.02% octanol and 0.05% pentaerythritol monoformal and the mixture is heated to solution. The solution is resistant to the release of paraformaldehyde at 0°C for more than 30 days.

Example 7.

To a formaldehyde solution with a content of 37.2% formaldehyde and 0.3% methanol, 0.1% butyroguanamine, 0.005% pentearythrite monopalmitate and 0.05% decanol are added. The mixture is heated to accelerate the dissolution and undissolved substance is separated by filtration. This solution is resistant to the release of paraformaldehyde for more than 30 days at 0°C

Example 8.

To a formaldehyde solution with a content of 37.2% formaldehyde and 3% methanol, 0.08% benzoguanamine, 0.05% sorbitol trimethylene ether and 0.05% heptanol are added and dissolved in heat. The solution is resistant to the release of paraformaldehyde for more than 30 days at 0°C.

Example 9.

To a formaldehyde solution with a content of 37.2% formaldehyde and 7% methanol is added a methylacetoguanamine which mainly consists of the tetramethylol derivative, equivalent to 0.1% acetoguanamine, and 0.0005% pentaerythritol stearate (a mixture with high mono- stearate content) and the mixture is dissolved in the heat. After cooling to room temperature, undissolved substance is removed by filtration. During 7 days of storage at -i- 6.6°C, no paraformaldehyde is released from this solution.

Example 10.

To a formaldehyde solution with a formaldehyde content of 37.2% and a methanol content of 7% is added a methylolbenzoguanamine, which mainly consists of the tetramethyl derivative, equivalent to 0.1% benzoguanamine, and 0.05% polyethylene glycol stearate. The mixture is heated for dissolution and, after cooling to room temperature, the mixture is freed from undissolved substance by filtration. During 7 days of storage at + 6.6°C, no paraformaldehyde is released.

Example 11.

To a formaldehyde solution with a formaldehyde content of 37.2% and a methanol content of 7%, 0.05% butyroguanamine, 0.05% benzoguanamine and 0.01% polyvinyl alcohol are added and the whole is heated to solution. After 8 days of storage at 6.6°C, no paraformaldehyde is released.

Example 12.

Crude formaldehyde solution obtained by methanol oxidation on a metallic silver contact with a high methanol-air ratio is added to 0.02 percent 2-ethylhexanol, 0.0001 percent pentaerythritol stearate and 0.1 percent acetoguanamine, which was transferred with excess formaldehyde into a methylol derivative, and is then adjusted to a concentration of 37.1 percent formaldehyde and 7 percent methanol (the amounts of stabilizer calculated on parts by weight in the adjusted solution). During 8 days of storage at 6.6°C, no paraformaldehyde is released from this solution.

Example 13.

Crude formaldehyde solution from the same source as in example 12 is added 0.02 percent hydroquinone, 0.001 percent polyethylene glycol stearate and 0.1 percent benzoguanamine which had been transferred in a methylol derivative with an excess of formaldehyde, and then adjusted to a concentration of 37 ,1 percent formaldehyde and 7 percent methanol (the amounts of stabilizer are calculated according to the weight amounts in the set solution). A paraformaldehyde excretion does not occur during 8 days of storage at -r- 6.6°C.

Example 14.

To a formaldehyde solution with a content of 45.2% formaldehyde and 1% methanol is added methylacetoguanamine, which mainly consists of the tetramethylol derivative, equivalent to 0.1% acetoguanamine, and 0.05% polyethylene glycol stearate. After dissolution in the heat, the mixture is cooled to room temperature and the undissolved substance is removed by filtration. When stored at 25°C, the solution is resistant to the release of formaldehyde for more than 30 days.

Example 15.

To a formaldehyde solution with a content of 45.2% formaldehyde and 1% methanol, add the condensation product of benzoguanamine and glyoxal (molar ratio 1:1), equivalent to 0.1% benzoguanamine, and 0.005% pentaerythritol dipropyl ether and dissolve in the heat. Under

Claims (2)

After 30 days of storage at 25°C, no paraformaldehyde precipitates from this solution. Example 16. To a formaldehyde solution with a content of 45.2% formaldehyde and 1% methanol, 0.05% acetoguanamine, 0.05% benzoguanamine and 0.05% polyvinyl formal are added and dissolved by heating. Undissolved substance is removed by filtration. No paraformaldehyde is released from this solution after 30 days of storage at 25°C. Example 17. To a formaldehyde solution with a content of 45.1% formaldehyde and 1% methanol, add 0.1% acetoguanamine and 0.05% polyvinyl acetate and dissolve well in the heat. The solution is resistant to the excretion of paraformaldehyde during 30 days of storage at 25 °C. Example 18. To a formaldehyde solution with a content of 45.1% formaldehyde and 1% methanol, 0.1% benzoguanamine, 0.05% pentaerythritol monooleate and 0.05% polyvinyl formal are added and dissolved sufficiently in the heat. The undissolved substance is separated by filtration. After 30 days of storage at 25°C, no paraformaldehyde has been secreted from this solution. Example 19. Crude formaldehyde solution, obtained by methane oxidation on a metal oxide catalyst with an excess of air, is added 0.02 percent hydroquinone, 0.02 percent 2-ethylhexanol, 0.0001 percent pentaerythritol stearate and 0.1 percent benzoguanamine which with an excess of formaldehyde was transferred in a methylol derivative, and then adjusted to a concentration of 45.1% formaldehyde and 1% methanol (the amounts of stabilizer are measured by weight of adjusted solution). A paraformaldehyde release from this solution did not occur after 30 days of storage at 25°C. Example 20. Crude formaldehyde solution from the same source as in example 19 is added 0.02% hydroquinone, 0.005% polyethylene glycol stearate and 0.1% benzoguanamine which had been transferred into a methylol derivative by means of an excess of formaldehyde, and then adjusted to a concentration of 45.1 percent formaldehyde and 1 percent methanol (the amounts of stabilizer are measured based on the amount by weight in the adjusted solution). A paraformaldehyde release from this solution did not occur after 30 days of storage at 25°C. Example 21. To a formaldehyde solution with a content of 50.2% formaldehyde and 1% methanol, 0.1% acetoguanamine, 0.05% polyvinyl alcohol and 0.02% 2-ethylhexanol are added and dissolved in the heat. A paraformaldehyde release from this solution does not occur after 3'0 days of storage at 40°C. Example 22. To a formaldehyde solution with a formaldehyde content of 50.2% and a methanol content of 1%, 0.1% benzoguanamine, 0.05% pentaerythritol monopalmitate and 0.05% polyvinyl acetate are added and dissolved in the heat. The insoluble substance is separated by filtration. A release of paraformaldehyde does not occur during a 30-day storage at 40°C. Patent claim: 1. Method for stabilizing aqueous formaldehyde solutions, in particular formaldehyde solutions containing 30-55 weight percent formaldehyde and up to 8 weight percent methanol against the excretion of paraformaldehyde by the addition of guanamine derivatives, characterized in that the solution is added a) at least one guanamine with the usual fnrmel wherein R means a hydrocarbon residue, its methylol derivative and/or its condensation product with an aldehyde and b) at least one ester of a polyhydric alcohol with a higher fatty acid, an ether or an acetal of a polyhydric alcohol, a higher alcohol, hydroquinone, a polyvinyl alcohol, an ester or an acetal of a polyvinyl alcohol. 2. Method as stated in claim 1, characterized in that the guanamine compounds mentioned under a) are added in an amount of 0.01-1.0 weight percent and the compounds mentioned under b) are added in an amount of 0.0001-0.1 weight percent.