SK91994A3 - : Addition to adhesives and emulsions containing formaldehyde - Google Patents

Abstract

The additive for adhesives and emulsions containing formaldehyde is composed of non-hydrolyzed and/or hydrolyzed, preferably in the form of glue, collagen and/or keratin, and/or casein, a preservative and water. As a preservative, chromium and/or chromate ions and/or phenol, salicylic acid, trihydroboric acid, sodium fluoride, or 2-naphthol are used. The water content is determined by the form of application.

Description

Addition to adhesives and emulsions containing formaldehyde

Technical field

The technical solution relates to an additive for adhesives and emulsions containing formaldehyde which reduces the formaldehyde content.

Current 3-state technology

Up to now, the addition or reduction of formaldehyde in urea-formaldehyde, phenol-formaldehyde, resorcinol-formaldehyde and melamine-formaldehyde adhesives has been used. an excess of formaldehyde-reactive substances, generally in particular urea, melamine, or resorcinol. However, the use of an excess of these components adversely affects the properties and technological process of producing the resulting particleboard or plywood materials.

Disodium tetraborate and urea-modified sulphite liquor are also mentioned as active ingredients in urea-formaldehyde adhesives. A negative accompanying property of adhesive compositions containing these additives is the reduced reactivity of the components, which must be eliminated by the use of another additive, a mixture of calcium chloride and urea reactive with formaldehyde, such as e.g. p-toluenesulfonamide, ethylenediamine and others (Japanese Patent 7128784 and 7444060). In practice, however, these additives have been shown to reduce the amount of formaldehyde released upon curing of the adhesive, respectively. gradually released from the products as insufficiently effective.

In paraffin emulsions, olein has also been used as an emulsifier, which also contains odorous proportions of lower fatty acids, which reduce the quality of the final products.

more effective hardener. Like ureas and addition compounds Substances are also patented

SUMMARY OF THE INVENTION

The aforementioned drawbacks are remedied by an additive for adhesives and emulsions containing formaldehyde, which consists in that it is composed of non-hydrolyzed and / or hydrolyzed, preferably in the form of glues, collagen and / or keratin and / or casein, a preservative and water. As preservative, the additive comprises 0.3 to 3000 mg / kg of chromium and / or chroman ions and / or 0.1 to 2 wt.% Of phenol and / or 0.1 to 2 wt.% Of sallcilic acid and / or 0.1. % to 8 wt.% 58 borohydride and / or 0.1 to 1 wt.% sodium fluoride; The water content of the additive is, depending on the form of application, in the range of 0.01 to 99% by weight.

The addition of formaldehyde-containing adhesives and paraffin emulsions serves to bind free formaldehyde, thereby significantly reducing its emission. Additive systems are well foaming, tolerate the addition of standard fillers and, after drying, have comparable mechanical properties to materials prepared by the present technology, with the required amount of additive being several times lower than the previously used additives.

DETAILED DESCRIPTION OF THE INVENTION

Application of the additive according to the invention is shown in the following examples.

1. Additive in particleboard with urea-formaldehyde adhesive 9 wt.% Was used to prepare the hydrophobic paraffin emulsion. 58 skin glue prepared by hydrolysis by boiling and drying non-hydrolyzed bovine skin collagen material containing 350 ppm total chromium, further 17 wt.58 paraffin and 74 wt% water. The paraffin emulsion was applied to the 3T urea formaldehyde (UF) adhesive using ammonium chloride as a hardener. With an adhesive deposit of 10 wt.58, a particle board of 25x15x2 cm was prepared at a pressing temperature of 140 ° C. A significant reduction of formaldehyde emission to 0.028 mg / m ³ was achieved compared to 0.184 mg / m ³ from a comparative chipboard sample made of 3T cured with phosphoric acid. Mechanical properties of the board: bending strength of 22 MPa, peel strength of 0.4 MPa, swelling after 24 hours. 4,8 9S.

2. Additive in paraffin emulsion.

Using a pigskin skin glue containing 600 ppm total chromium, a paraffin emulsion was prepared at 75 ° C with a paraffin content of 25 wt.%, A glue component of 15 wt.% And a water content of 60 wt.%. The emulsion was added in an amount of 4% to the 3F UF adhesive and cured at 100 ° C using 1 wt% ammonium chloride as a catalyst. The system was compared to an emulsion where olein was used as an emulsifier. The cure rate of the adhesive composition (condensation time) at 100 ° C was comparable to that of the comparative emulsion (92 and 95 seconds). Formaldehyde release during curing was ca 42% lower in the glue additive system than in the comparison system (0.225 vs. 0.387 mg formaldehyde / kg adhesive).

3. Phenol formaldehyde glue admixture.

Additive prepared by mixing ground dry bone size (20 parts by weight), 10% by weight. parts of skin glue and 10 wt. parts of casein glue containing 100 mg / kg chromium ions and 0.5 wt.% phenol was dissolved at 60 ° C in 60 wt. parts of water and was applied at a ratio of 1:30 to a phenol-formaldehyde adhesive mixture from an aqueous solution of strongly alkaline phenol-formaldehyde resol (Umaform B115) at 20 ° C.

The adhesive mixture was air dried at 100 to 120 ° C and then cured at 140 to 150 ° C. A control sample of adhesive without additive 9a was prepared in parallel under the same conditions. The content of free formaldehyde in the sample with the addition of wt. parts prepared was ca 54% lower than in the control (0.18 wt% vs. 0.39 wt% formaldehyde). The release of formaldehyde from the additive sample was cured by approximately 36 during curing than from the control sample (0.145 vs. 0.198 mg formaldehyde / kg adhesive composition).

Industrial usability

In the woodworking, furniture and chemical industries in the manufacture of particle board, agglomerated materials, plywood, formaldehyde-containing adhesives, paraffin emulsions for the preparation of formaldehyde-containing adhesive mixtures, and the like. By reducing the formaldehyde content, the effect of the additive contributes to the protection of the environment and the working environment.

Claims (3)

PATENT CLAIMS Additive for adhesives and emulsions containing formaldehyde, characterized in that it is composed of non-hydrolyzed and / or hydrolyzed, preferably in the form of glues, collagen and / or keratin and / or casein, a preservative and water. 2 Additive for adhesives and emulsions containing formaldehyde according to claim 1, characterized in that it contains as preservative component 0.3 to 3000 mg / kg of chromium and / or chromate ions and / or 0.1 to 2% by weight of phenol and / or 0, 1 to 2 wt.% Salicilic acid and / or 0.1 to 8 wt.% Trihydrogen boronic acid and / or 0.1 to 1 wt.% Sodium fluoride and / or 0.01 to 0.2 wt.% 2-naphthol. 3. Additive for adhesives and emulsions containing formaldehyde according to claim 1, characterized in that it contains 0.01 to 99% of water.