CS239368B1 - Method of modifying adhesives - Google Patents

Abstract

The method of modifying adhesives based on urea-formaldehyde condensates consists in adding to the adhesive mixture, before the adhesive is cured by the action of acid catalysts, the following thermodynamically unstable oxygen compounds from the group of inorganic and/or organic peroxy compounds, such as barium peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, decanoyl peroxide, bis-(1-hydroxycyclohexyl) peroxide, t-butyl peroxyacetate, t-butyl peroxybenzoate, 2,5-dimethyl-2,5-di(t-butylperoxy) hexane, t-butyl hydroperoxide, or thermodynamically unstable mixtures formed by mixing a peroxy compound or a strong oxidant with at least one stable substance, such as an equimolar mixture of hydrogen peroxide with cyclohexane, or ozonized air, in an amount of 0.5 to 25% by weight per weight of the adhesive mixture. The invention can be used in the production of adhesives intended primarily for gluing wood materials.

Description

239368 3 4

SUMMARY OF THE INVENTION The present invention provides a modification of adhesives for urea-formaldehyde condensate formulations, especially for bonding woody materials, in particular chipboard, fiberboard, veneer, plywood, cardboard, paper, and the like, such that the form-aldehyde is released and favorably reduced. affect physico-mechanical indicators.

A number of processes for the production of amine plastic adhesives are known. One of the problems addressed by researchers in the development of new manufacturing processes and applied adhesives is the avoidance of loose formaldehyde from the adhesive product. The removal of formaldehyde odor can be achieved by many methods. For example, the addition of phenol by the pre-polycondensation step (U.S. Pat. No. 3,547,868) is known, the reduction of formaldehyde is achieved by the potency of ammonia or alkali metal phosphate in urea-formalin reaction (Japan Kokai 73-60,737), protein-uptake absorption (JapanKokai 73 By mixing amine lining with acetoacetates, acetylacetonates or malonates (Japan Kokai 73-60, 140) by addition of aliphatic amides, thioamides, imines or amines to the adhesive (Ger, Offen. 696), by addition of m-phenylenediamine, dicyanediamide or resorcinol, which can be added to the produced adhesive or introduced into the reaction mixture during the final step synthesis (A. Zmi-horska, S. Wlodzimierz: Polimery 18, No. 5). 12, 639 (1973).

Modification of adhesives with various polyacids and / or capable polyreases has proven to be useful, with the use of various forms of lig-sulphonic acid (MS Author's Certificate No.22.450) and others. Another way to reduce the release of formaldehyde is to reduce the molar ratio of formaldehyde to urea in the adhesive manufacturing process. However, from this reduced molar ratio, there are adhesives with reduced adhesive capacity, thereby impairing the mechanical properties of the bonded joints (articles). Due to the fact that the adhesive capacity of the adhesive is proportional to its volume, it compensates for the deteriorated properties of urea-formaldehyde adhesives with a reduced formaldehyde molar monomer by applying an increased amount of adhesive to the adhesive and / or special adhesives. , plaster, etc.), which leads to a deterioration of the mechanical properties of the joint.

The disadvantage of the above-mentioned methods is the fact that the additives used do not meet the requirements of protection of the working and living environment, or they do not guarantee the required quality of the glued joint. The use of acid catalysts (curing agents), which are peroxyacids and / or precursors in the manufacture of molded bodies (German Pat. No. 2,716,375) is preferred. The present invention utilizes conditions such that during curing releasing the appropriate acid in the "in situ", which is ensured by the lower temperature of the curing process and promoting the addition of formaldehyde.

The realization of the present invention requires higher demands on the quality of the raw materials, the control technique and the technological discipline of the operator. Decomposition of the undesired direction of the balanced peroxyacid and / or pre-cursor, in which bubbles form, leads to a deterioration of the physico-mechanical properties of the shaped bodies. Further, the addition of formaldehyde during curing results in its release into the working environment. More preferably, the foaming is terminated by curing the adhesive with acidic catalysts which maintain the mechanical properties of the bond. Two methods are known for foaming of urea-formaldehyde adhesives: I. by air using emulsifiers II. by means of the thermodynamically non-stable compounds

Attention is drawn to the thermodynamically unstable nitrogen compounds (U.S. Pat. No. 225,416 and 225,417), which reduce the release of formaldehyde by beneficially affecting the physico-mechanical properties.

The compounds of the second method qualitatively broaden the present invention.

According to the present invention, the process for modifying urea-formaldehyde condensate adhesives associated with the foaming and curing of the adhesive by acid catalysts is accomplished by adding to the adhesive composition the following thermodynamically unstable oxygen compounds from the inorganic group and / or organic peroxygen compounds such as barium peroxide, benzyl peroxide, 2,4-dichlorobenzoyl peroxide, lauryl peroxide, decanoyl peroxide, bis (1-hydroxycyclohexyl) peroxide, t-butyl peroxyacetate, t-butyl peroxybenzoate, 2,5-dimethyl-2,5-di- (t-butylperoxy) hexane, t-butyl hydroperoxide, or thermodynamically unstable compounding by mixing a peroxy compound or a strong oxidant with at least one stable substance such as equimolar hydrogen peroxide mixture with cyclohexane, or ozonized air , in an amount of 0.5 to 25p. wt. on the weight of the adhesive composition. An advantage of the present invention is the beneficial effect of physico-mechanical inducers such as hardness, strength and bond strength of the bond, achieving a substantial reduction in the formyldehyde released, especially in the production of particle boards below 10 mg free form. - with 6 2 3.9 3 8.8 aldehyde per 100 g of absolute dry thatch (according to the valid FESIP method). For the application of such chipboard boards in wooden constructions, this means that environmental protection requirements are met without the need for special surface treatment of these boards, thus further reducing the costs compared to the previously known and used methods.

The perzoo compounds are essentially unstable compounds due to the weak peroxydic bond they contain. This bond is readily cleavable (heat, radiation, catalysts, and the like) to form one or more radicals, which, in particular, are curing agents of free formaldehyde, especially when cured. When decomposing, gaseous products which generally contain carbon dioxide, methane, ethane, oxygen, and the like according to the type of peroxy compound are formed. The pressure of said decomposition products ultimately contributes significantly to increasing the adhesive capacity and reducing the consumption of glue in the glueing process.

The greater effect of the invention is further elucidated by the following examples, which are not to be construed as limiting the scope of the invention. Example 1

The adhesive zines are prepared by mixing 125 parts by volume of urea-formaldehyde adhesive, 2.5 parts by volume of 15% by weight of ammonium chloride solution, 15 parts by volume of paraffin emulsion and 46 parts by volume of water.

Adhesive zippers are dosed with a chipboard dispensing device containing 4.2 pounds. wt. moisture, in an amount of 13 parts by weight of the adhesive composition to 90% by weight. dielovdrevotriesok. The mass formed is formed into a carpet by a known method which preforms the carbon black at normal temperature and then presses it at 120 ° C for 6 minutes. The chipboard corresponds to the serial product and has the following parameters:

Flexural Strength (MPaj 17.1

Strength perpendicular to thatch plane (MPa 0.4Specific weight (kg.m'3) 780.0

FESIP free formaldehyde content (in mg per 100 g absolute dry thatch) 24.5 Example 2 K 100 wt. of the adhesive composition, such as Example 1, 15 wt. % sodium peroxide and 10 wt. % of peroxidubaric (i.e., 25% by weight of lepiacuzmes). After homogenization, the procedure of Example 1 is followed, except that the woman is 90 wt. parts of the particleboard are 10 wt. parts of adhesive additive composition. In the resulting chipboard, the following parameters are set:

Flexural Strength (MPaj 17.5

Strength perpendicular to the thatch plane (MPa 0.4Specific weight (kg.m-3) 780.0

FESIP free formaldehyde content (in mg per 100 g of absolute dry thatch) 15.5 Example 3 K 100 wt. part of the adhesive composition, such as Example 1, is added 10 wt.% of benzoyl peroxide containing 25 wt. water (i.e., 10% by weight of the adhesive composition, which is characterized by a decomposition temperature of 110.5 ° C. After homogenization, the process is carried out according to Example 1, with the difference that 90% 10 parts by weight of the glue mixture is speroxide, the following parameters are determined for the resulting particleboard:

Flexural Strength (MPa 18.4

Strength perpendicular to the thatch plane (MPaj 0.5Specific weight (kg.m-3) 770.0

FESIP free formaldehyde content (in mg per 100 g of absolutely dry yam 8.5 Example 10 10 parts by weight of 2,4-dichlorobenzoyl peroxide in the form of 50% by weight are added to 100 parts by weight of the adhesive composition, such as Example 1) passages with dibutyl phthalate (i.e. 10% by weight adhering composition, characterized by a decomposition temperature of 81.5 ° C. After homogenization, the procedure of Example 1 is followed, except that 90 parts by weight of the particleboard are metered in 9.5 parts by weight of the adhesive composition with the additive The following parameters are determined for the resulting particleboard:

Flexural Strength (MPaj 18.1

Thickness Thickness (MPa 0.5Specific Weight (kg.mr3) 760.0

FESIP free formaldehyde content (in mg per 100 g absolute dry thatch) 9.0 Example 5 K 100 wt. part of the adhesive composition, such as Example 1, is added 4.0 wt. dielovlauroyl peroxide (i.e., 4.0% by weight on the weight of the adhesive composition), which is characterized by a decomposition temperature of 84 ° C. After homogenization, the procedure of Example 1 is followed, except that 90 wt. die-chipping of chipboard is dosed 10 wt. die-lov glue mixture with additive. In the resulting particle board, the following parameters are set. 239368 7 8

Flexural strength (MPa) 17.9

Strength perpendicular to plane (MPa) 0.5Specific weight (kg.m-3) 760.0

FESIP free formaldehyde content (in mg per 100 g absolute dry) thatch 9.5 Example 6 K 100 wt. of a glue mixture such as Example 1, 6.0 wt. dielovdanoyl penixide (i.e. 6.0% by weight of the adhesive composition), which is characterized by a decomposition temperature of 75.5 degrees Celsius. After homogenization, the procedure of Example 1 is followed, except that 90 wt. 8 wt. parts of an adhesive composition with an additive. For the resulting wood-pulp, the following parameters are set:

Flexural Strength (MPa) 18.0

Strength perpendicular to plane (MPa) 0.5Specific weight (kg.m-3) 760.0

FESIP free formaldehyde content (in mg per 100 g of absolute dry thatch) 9.2 Example 7 To 100 wt. part of the adhesive composition, such as Example 1, is added 12.0% by weight of dielovbis (1-hydroxycyclohexyl) peroxide (i.e., 12.0% by weight by weight of adhesive composition), which is characterized by the temperature of de After homogenization, it is carried out according to Example 1, with the difference that 10 parts by weight of the adhesive mixture is metered into 90 parts by weight of the chipboard by pressing and is carried out at 150 ° C for 7 minutes. Chipboard The following para-meters are provided:

Flexural Strength (MPa) 19.5

Strength perpendicular to plane (MPa) 0.6Specific weight (kg.m-3) 765.0

FESIP free formaldehyde content (in mg per 100 g absolute dry thatch) 15.1 Example 8 K 100 limot. part of the adhesive composition, such as Example 1, is added 5.0 wt. of t-butyl peroxyacetate containing 25% benzene (i.e., 5.0% by weight of the weight of the pollutant mixture), which is characterized by a decomposition temperature of 157.5 ° C. After homogenisation, the procedure of Example 1 was followed, except that 90 wt. 12 wt. a part-glue mixture and compression is carried out at 150 ° C for 7 minutes. For the resulting chipboard, the following parameters are determined:

Flexural Strength (MPa) 19.6

Strength perpendicular to plane (MPa) 0.5Specific weight (kg.m 3) 770.0

FESIP free formaldehyde content (in mg per 100 g absolute dry thatch) 10.1 Example 9 K 100 wt. part of the adhesive composition, such as Example 1, 1.5 wt. part-butyl peroxybenzoate (i.e. 1.5% by weight of the adhesive composition), characterized by a decomposition temperature of 111.5 degrees Celsius. After homogenization, the process is carried out according to Example 1, with the exception that 90 wt. 10 parts by weight of chipboard. parts of the adhesive mixture, the molding is carried out at 140 ° C for 7 minutes. The following chip-meters are provided for the resulting particleboard thatch:

Flexural Strength (MPa) 17.5

Strength perpendicular to the plane (MPa) 0.4Specific weight (kg.m "3) 780.0

FESIP free formaldehyde content (in mg per 100 g absolute dry thatch) 15.4 Example 10 K 100 wt. of the adhesive composition, such as Example 1, 18.0 wt. parts of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (i.e. 18.0% by weight of the adhesive composition), which is characterized by a de-composition temperature of 145 ° C. After homogenization, it is carried out according to Example 1, with the difference that 90 wt. parts of chipboard dosed 8 wt. parts of the adhesive mixture, the molding is carried out at 150 ° C in the form of 7 inches. The following chip-meters are provided for the resulting particleboard thatch:

Flexural Strength (MPa) 18.2

Strength perpendicular to the root (MPa) 0,5Specific weight, (kg-m "3] 740,0

FESIP free formaldehyde content (in mg per 100 g of absolutely dry thatch) 9.2 Example K 100 wt. part of the adhesive composition, such as Example 1, 15.0 wt. tert-butyl hydroperoxide (i.e., 15.0% by weight of the adhesive composition), characterized by a decomposition temperature of 97 ° C. After homogenization, the procedure is as in Example 1, with the exception of 90 wt. parts of the particleboard are 8 wt. parts of the adhesive composition and compression is performed at 140 ° C for 7 minutes. For the resulting particleboard, the following parameters are set:

Claims (1)

g 10 239388 Flexural strength (MPa) 17,2 Strength perpendicular to thatch (MPa) 0,5Specific weight (kg.nr3) 760,0 FESIP free formaldehyde content (in mg per 100 g of dry dry thatch) 9,5 Example 12 K 100 wt. part of the adhesive composition, such as Example 1, 12.0 wt. dielectric succinic acid (i.e., 12.0 ° C / w by weight of the adhesive composition) characterized by a 120 ° C decompression temperature. After homogenization, the procedure described in Example 1 is followed, except that 90 wt. 10.0 wt. and the molding is carried out at 150 ° C for 7 minutes. The following particle meters are determined for the resulting chipboard: V bending strength (MPa) 17.4 Strength perpendicular to the plane (MPa) 0.5Specific weight (kg.m ~ 3) 770.0 FESIP free formaldehyde content (in mg per 100 g of dry dry thatch) 8.5 Example 13 K 100 wt. part of the adhesive composition, such as Example 1, is added 10.0 wt. a fractional-molar mixture of hydrogen peroxide with cyclohexanone (i.e. 10.0% by weight on the weight of the adhesive composition). After homogenization, the procedure of Example 1 is followed, except that 90% by weight is obtained. 10 wt. parts of the adhesive composition with the additive. The resulting particleboard exhibits the following parame- ters: Bending strength (MPa) 17.4 Strength perpendicular to the plane (MPa) 0.5Specific weight (kg.m_jj 772.0 FESIP free formaldehyde content (mg / 100 g EXAMPLE 14 100 parts by weight of the adhesive composition as in Example 1 are blown by blowing off the air containing 3% by volume of ozone, followed by Example 1 after foaming the adhesive mixture, except that 10 parts by weight of the foamed mixture are metered into 90 parts by weight of the chipboard The resulting particleboard shows the following parameters: Bending strength (MPa) 17.2 Strength perpendicular to the plane (MPa) 0.4Specific weight (kg.m ~ 3) 730.0 FESIP free formaldehyde content (in mg per 100 g of dry dry thatch) 10.0 PRES Μ ET A method for modifying inoculum-based formaldehyde-based glues based on the foaming and curing of acid catalysts, characterized in that the oxygen composition of the selected groups of inorganic and / or organic peroxy compounds, such as barium peroxide, ben-zoyl peroxide, 2,4-dichlorobenzoyl peroxide, lauloyl peroxide, decanoyl peroxide, bis (l), are added thermodynamically unstable oxygen compounds. -hydroxycyclohexyl) peroxide, t-butylperoxyacetate, t-butylperoxybenzoate, 2,5-dimethyl-2,5-di- (t-butylperoxy) hexane, t-butyl hydroperoxide, or thermodynamically unstable compounding by combining the peroxy compound or a strong oxidant with at least one stable substance, such as an equimolar mixture of hydrogen peroxide with cyclohexane, or an ozone air, in an amount of 0.5 to 25% by weight. on the weight of the adhesive composition.