SK81394A3 - Method of preparation of modified phenol butimens and their use - Google Patents

Abstract

The invention relates to a process for the preparation of phenolresols for foams, particularly for flower-arranging foams, in which monosaccharides or disaccharides, sugar alcohol or urea-formaldehyde condensation products are added to the starting materials for resol resin preparation. The foams produced in this way are biodegradable, for example during composting.

Description

The use of modified phenolic resins for their use

SUMMARY OF THE INVENTION The present invention relates to modified phenol-formaldehyde resol type foam resins for the production of biodegradable, duroplastic phenolic resin resins.

The use of degradable plastics is increasingly increasing to meet the requirements. It is known that by modifying thermoplastics it is possible to achieve biodegradability. Biodegradable thermosets are not yet known.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide phenol-formaldehyde foams from which duroplastic foams (thermosets) having biodegradability can be produced.

The problem is solved by producing and foaming the modified phenol resols according to claims 1 to 4.

According to the invention, it is surprisingly possible to modify the starting materials for the production of phenolic resins before condensation to the resin, i. no. to the phenol / formaldehyde mixture, as well as to their other ingredients, without limiting condensation and foaming. Suitable amounts of admixtures are from 5% to 50% by weight based on phenol. The impurities do not prevent the condensation of the resins and allow the formation of foam of the same quality as without impurities. Foam with admixtures disintegrate in wet conditions and microorganisms.

Mono- and disaccharides, the corresponding carbohydrate alcohols, as well as urea-formaldehyde condensation products, which, in a similar way to carbohydrates, contain several -OH groups, e.g. no. low-molecular-weight, water-soluble substances, with a plurality of, if appropriate, a large number of -OH groups.

The condensation of phenolic resins with their admixtures takes place under normal production conditions and without changing the typical characteristics of the foamed resins or the foamed products produced therefrom.

The resin feedstock of phenol and optionally cresol can be condensed in the customary manner in the amounts of formaldehyde intended for this purpose by the addition of hot alkali, the additives according to the invention being present from the beginning. Conventional basic condensation agents such as NaOH, barium hydroxide or ammonia can be used in known amounts. After the condensation of the resin is. It is neutralized in the usual manner with acids and dried to a viscosity of preferably 2000 to 12000 mPa.s, measured at 20 [deg.] C. in vacuo. From the analyzes. surprisingly, the added substances are surprisingly still partially free after condensation of the resin.

For the production of foams, resins at room temperature are mixed with an expandable substance, with low boiling expansives such as hydrocarbons and mixtures thereof boiling between 36 and 80 ° C being preferred. Acid reinforcing agents such as toluol- or phenolsulfonic acids as well as surfactants are added.

Surfactant mixtures which act hydrophobically are used for the production of substantially hydrophobic foams, while hydrophilic surfactant mixtures are used for preferred cut-off foam foams. Such foams are used in particular for the production of shaped articles for the treatment of cut flowers, but also for the production of water-soaked protective containers for the transport of flowers.

The water soak, important for this purpose, should be in the vicinity of 80% water, based on the foam volume, by the choice of surfactants, and the water soak rate should be large and should not exceed a few minutes.

The foams used to stab the cut flowers in their treatment are usually colored, preferably green dyes. Surprisingly, it has been found that these foams have excellent color fastness due to the additives according to the invention.

The foaming of the resins takes place in a customary manner at temperatures from 40 to 60 [deg.] C. in a heated mold or in a double press, while at the same time hardening occurs.

A typical foam is characterized by:

solid resin content viscosity / 20 ° C, Hoeppler / water content / according to Karl Fischer / free phenol free formaldehyde resin reactivity

- 84% by weight.

2,000 - 10,000 mPa.s

- 20% by weight.

- 10% by weight.

0.2-3% by weight. 100-150 ° C.

The reactivity of the foam resin as a measure of the stiffening rate is determined by measuring the maximum temperature after adding a certain amount of standard stiffening versus time.

A typical frothing formula is as follows:

1 00 weight parts bitumen 2 - 8 weight parts surfactant mixtures 5 - 1 0 weight parts expandable substances 5 - 15 weight parts stiffening and 0,5 - 2 dye parts by weight.

Preferably, the surfactant mixtures are from a nonionic surfactant and an anionic surfactant in a weight ratio of 1: 5 to 5: 1.

Furthermore, it has been found that the flower-forming foams produced in this way are also perfectly suitable for crop-free crops of ornamental and useful plants using nutrient solutions.

In order to test the biodegradability of the described foams for the cutting of cut flowers, a series of experiments were carried out at the Institute for Vegetable Growing of the Technical University of Hannover. The foam was mixed in different proportions with the compost, the mixtures were placed in glass containers, and 24-hour CCl 2 production was measured as a degradation rate up to three weeks apart. Initially, the measured values were far above those corresponding to the ratio of compost to foam mixing, indicating the degradation of the duroplastic foam. The series was completed after 4 months. For flower dressing foams made from unmodified phenolresols without additives according to the invention, there was no 'degradation' by 'microorganisms' even after - 6 months of composting.

Examples of the invention

Note: Percentages of substances in solutions are weight percentages unless otherwise stated.

Example 1

1000 parts by weight of phenol dissolved in 100 parts by weight of water are mixed with 1.294 parts by weight of a 37% aqueous formaldehyde solution, 250 parts by weight of lactose monohydrate and 53 parts by weight of barium hydroxide octahydrate. The mixture was heated to 85 ° C with stirring and maintained at this temperature for 130 minutes. After neutralization with 21 parts by weight of 25% sulfuric acid, the aqueous resin solution is dried under vacuum (13 mbar, 60 ° C) until the resin test shows a viscosity of 77%. the reactivity of the resin lies at t = 127 ° C, the free phenol content

9.7% by weight, free formaldehyde content 1% by weight, free lactose content 2% by weight.

Example 2

1,000 parts by weight of phenol dissolved in 100 parts by weight of water are mixed with 1,294 parts by weight of a 37% aqueous formaldehyde solution, 715 parts by weight of a 70% aqueous sorbitol solution and 70 parts by weight of barium hydroxide octahydrate. The mixture was heated to 85 ° C with stirring and maintained at this temperature for 85 minutes. After neutralization with 67 parts by weight of 25% sulfuric acid, the aqueous resin solution is dried under vacuum until the resin test shows a viscosity of 5-400 mPa · s (25 ° C) at 82% solid resin content. The reactivity of the resin lies at t = 117 ° C. Free phenol content 7.4%, free formaldehyde content 0.6%, free sorbitol 9.5%.

Example 3 / Resin 1 /

1000 parts by weight of phenol dissolved in 100 parts by weight of water are mixed with 1.294 parts by weight of a 37% aqueous formaldehyde solution, 250 parts by weight of glucose monohydrate and 53 parts by weight of barium hydroxide octahydrate. The mixture was heated to 85 ° C and maintained at this temperature for 130 minutes. After neutralization with 21 parts of 25% sulfuric acid, the aqueous resin solution is dried under vacuum (13 mbar, 60 ° C) until the viscosity test of the resin shows 3 · 700 mPa.s (20 ° C by Hoeppler) at 78 ° C. % solids content. The reactivity of the resin is at t = 112 ° C. Free phenol content 8.9% by weight, ~ max. ´ ´ content of free formaldehyde 0,7% by weight, content of free glucose 3,2% by weight.

Example 4 / Resin 2 /

536 parts by weight of a 37% aqueous formaldehyde solution and 300 parts by weight of urea are maintained with 2 parts by weight of a 25% ammonia solution at 50 ° C for 15 minutes, by the addition of a mixture of triethanolamine / ammonia (4: 1 ratio) The precondensate is adjusted to pH 8 and left at 50 ° C for 30 minutes. To this mixture was added 545 parts by weight of phenol dissolved in 55 g of water, 706 parts by weight of a 37% aqueous formaldehyde solution, and

45.2 pbw of barium hydroxide octahydrate and the resulting mixture was held for 140 minutes at 85 ° C with stirring. After neutralization of 30 g of 25% sulfuric acid, the solution is dried until it has a viscosity of 3,600 mPa · s (20 ° C, Hoeppler) at a solid resin content of 78% by weight.

Example 5

200 g of resin are mixed with 14 g of a control mixture consisting of ionic and non-ionic surfactants, 0.9 g of a triphenylmethane derivative dye, 23 cm @ 2 of petroleum ether 40/80, and

22.5 ml acid stiffener. After stirring for 30 seconds, the reaction mixture is transferred to a paper bag and then placed in an oven at 60 ° C. After 30 minutes the hardening process is complete. The foam is characterized by the following data: density 25 l * water absorption rate (Ziegel / 55 s), water content> 90% v / v.

Example 6

200 g of resin 1 are mixed with 14 g of a control mixture consisting of ionic and non-ionic surfactants, 0.9 g of a triphenylmethane derivative dye, 22 cm @ 3 of petroleum ether 40/80 and 17.5 cnP acid stiffener, with stirring. After stirring for 30 seconds, the reaction mixture is transferred to a paper bag and then placed in an oven at 60 ° C. After 30 minutes the hardening process is complete. The foam is characterized by the following data: density = 25 kg / m < 2 >, water penetration rate / Ziegel / 80 s, water content 80% by volume.

Claims (5)

PATENT CLAIMS 1. Process for the production of modified phenolresols for the production of foams, characterized by the addition of mono- or disaccharides, carbohydrate alcohols or urea-formaldehyde condensation products as modifying agents to the starting materials of resol resin production. Process according to claim 1, characterized in that glucose, fructose, lactose or sorbitol is used to modify the foamed resins. Process according to claim 1 or 2, characterized in that the proportion of modifying agent is 5 to 50% by weight, based on phenol. Use of phenolresols produced according to one of Claims 1 to 3 for the production of biodegradable foams, in particular foams, for injecting cut flowers in their treatment. Duroplastic, biodegradable material made from the products of the process according to one of claims 1 to 3.