RU2425083C2 - Adhesive composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: adhesive composition is meant for gluing leather, rubber, polyurethane, PVC coatings, rigid plastic, metal, chip board, as well as for repairing furniture, plywood, scale wood, organic glass, paper, cardboard, cloth and fibre materials. The adhesive composition contains a mixture of Desmokoll ester urethane rubber, stabilising additives, a target additive and a solvent. The mixture of ester urethane rubber consists of three types of ester urethane rubber distinguished by viscosity. One of the rubber types has viscosity of 1500-2100 cP, the second has viscosity of 500-1000 cP and the third has viscosity of 400-800 cP. The stabilising additives in the composition are malonic acid and tinuvin, and the target additive is aerosil. The solvent is a composition containing acetone, ethyl acetate and toluene. The adhesive composition has frost-, vibration- and heat-resistance, as well as low toxicity.

EFFECT: adhesive composition forms a strong, highly elastic and strong adhesive joint.

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Description

Application area

The invention relates to adhesives based on polyurethane rubbers and is intended for bonding leather, rubber, polyurethane, PVC coatings, hard plastics, metal, chipboard, combinations of the above, for furniture repair, plywood, veneer, plexiglass, paper, cardboard, fabrics, fibrous materials .

State of the art

Known adhesive compositions based on urethane rubber for bonding shoe parts (patent RU No. 2047637, IPC ⁶ C09J 175/06, publ. 10.11.1995; patent RU No. 2096437, IPC ⁶ C09J 175/06, publ. 20.11.1997).

A disadvantage of the known compositions is the presence of a polyisocyanate as a hardener, which, being a derivative of the polymerization of hydrocarbons, is a toxic substance. In addition, the compositions are two-component, after the addition of a hardener, the adhesive has a pot life of about 4 hours. In view of these disadvantages, the known adhesive compositions are not environmentally friendly and economical.

Anles adhesive (St. Petersburg) based on BAYER DESMOCOLL ester urethane rubber containing various additives and a solvent is known (Internet site http://www.rankar.by/pages/partners/anles/klei/klei.htm )

Laboratory studies, the data of which are given in the example of a specific implementation of the claimed composition, show lower technical characteristics of the known adhesive in comparison with the claimed.

Closest to the claimed composition is an adhesive composition based on a mixture of ester urethane urethane rubbers of the Desmocoll series, including a hardener - polyisocyanate, stabilizing additives - malonic acid and tinuvin, and also a solvent containing methyl ethyl ketone, in the following ratio, wt.%:

Urethane rubber Desmocall 14.85-19.68 Hardener 1.5-2.0 Stabilizing additives: Malonic acid 0.81-0.72 Tinuvin B75 0.09-0.12 Solvent rest

(Application RU No. 2003120847, IPC ⁷ C09J 175/06, published ^on January 27, 2005).

The disadvantage of the prototype, as well as previous analogues, is the presence of polyisocyanate as a hardener. In addition, the solvent used is MEK (methyl ethyl ketone), which, as you know, belongs to the list of narcotic drugs and psychotropic substances.

The objective of the invention is the creation of an environmentally friendly adhesive composition with good technical and operational characteristics.

SUMMARY OF THE INVENTION

The problem is solved by the adhesive composition based on a mixture of ester urethane rubbers of the Desmoll series, containing stabilizing additives - malonic acid and tinuvin, a solvent. Unlike the prototype, the adhesive composition additionally contains the target additive of Aerosil, and its base is a mixture of ester urethane rubbers Desmocoll-540/4, Desmocoll-540/2 and Desmocoll-406 in the following ratio of components, wt. %:

Ester urethane rubber Desmocoll-540/4 12-16 Ester urethane rubber Desmocoll-540/2 1-3 Ester urethane rubber Desmocoll-406 0.5-1.5 Aerosil 0.2-1 Malonic acid 0.1-0.2 Tinuvin 0.05-0.08 Solvent rest

According to the invention, the adhesive composition as a solvent contains a composition comprising acetone, ethyl acetate, toluene in the following ratio, wt.%:

Acetone 58-74 Ethyl acetate 2-10 Toluene 4-8

According to the invention, the adhesive composition contains Aerosil 200, Tinuvin B75.

All Desmocoll ester urethane rubbers claimed in the composition are long chain linear polyester-polyurethanes with OH groups. Differ in the following:

Desmocoll-540/4 - contains more carboxylic acids and monomers; crystallization rate is high, thermoplasticity is low, viscosity is 1500-2100 centipoise.

Desmocall-540/2 - contains more carboxylic acids and monomers; crystallization rate is high, thermoplasticity is low, viscosity is 500-1000 centipoise.

Desmocoll-406 - has an amorphous structure, is less branched, contains less carboxylic acids and low molecular weight monomers; crystallization rate is low, thermoplasticity is high, viscosity is 400-800 centipoise.

The authors, on the basis of testing adhesive compositions using various urethane rubbers of the Desmocoll series, found that the most optimal characteristics of the adhesive are achieved with the composition and ratio of ester urethane rubbers indicated in the essence of the invention. The targeted addition of Aerosil provides increased bond strength, faster fixation and an increase in activation temperature. Environmental friendliness is achieved by the absence of hardener-polyisocyanate and additives such as methyl ethyl ketone in the composition.

Tests have shown that when Desmocoll-540/4 urethane-ester urethane rubber is added to the adhesive composition, less than 12% of the adhesive strength decreases, more than 16% - there is a high adhesive viscosity and poor adhesion to the material, which is inconvenient when working with adhesive. When adding Desmocoll-540/2 urethane rubber less than 1%, the strength characteristics of the adhesive drop, more than 3% - there is a high adhesive viscosity and poor adhesion to the material. With the addition of Desmocoll-406 less than 0.5%, the adhesive viscosity increases, the initial strength decreases; more than 1.5% - viscosity and initial strength are reduced. When Aerosil 200 is added less than 0.2%, the fixation of the adhesive composition is slowed down, and more than 1% - the adhesive viscosity increases and the strength of the adhesive joint decreases. With the addition of malonic acid less than 0.1%, fading resistance decreases, more than 0.2% - storage stability is lost. When B75 tinuvin is added, less than 0.05% of the adhesive joint loses elasticity, more, 0.08% - the adhesive viscosity decreases.

The prior art adhesive compositions based on ester urethane rubber "Desmocoll" (described in the "Prior art" section), as well as the addition of Aerosil to adhesive compositions, for example water-soluble (patent RU 2160754, IPC C09J 109/04, publ. 12/20/2000) or epoxy based.

The technical result of the invention is achieved by the totality of the features of the invention, determining the composition and ratio of components of the adhesive composition.

The preparation technology of the inventive adhesive composition is as follows.

Solvents — acetone, ethyl acetate, toluene — enter the glue preparation department from the solvent warehouse through process pipelines through a dispenser to a mixer. The dry components - Desmocall 540/4, Desmocall 540/2, Desmocall-406, Aerosil 200, tinuvin are delivered from warehouses and the rubber preparation department with special weights and loaded into the mixer through the loading hatch. The mixer is equipped with a cooling system. After loading all the components, circulating water is supplied, the breathing valve on the mixer opens and the mixer is turned on. After 5 hours of mixing the mixture, malonic acid is added and everything is mixed for another 3 hours. After 8 hours of stirring, the agitator shuts off and the breathing valve closes.

The advantages of the claimed adhesive composition:

- forms a strong, highly elastic, transparent, waterproof adhesive seam;

- perfectly glues highly plasticized materials, including PVC;

- it has frost. vibration heat resistance, low toxicity;

- Available fully ready for use.

An example of the preparation of the adhesive composition (1000 g).

To prepare the adhesive composition was taken:

Ester urethane rubber Desmocoll-540/4 13.7% - 137 g Ester urethane rubber Desmocoll-540/2 2.9% - 29 g Ester urethane rubber Desmocoll-406 1.1% - 11 g Tinuvin B75 0.07% - 0.7 g Aerosil 200 0.3% - 3.0 g Malonic acid 0.1% - 1 g Acetone 72.8% - 728 g Ethyl acetate 4.23% - 42.3 g Toluene 4.8% - 48 g Total 100% - 1000 g

All ingredients except malonic acid are mixed for 5-6 hours according to the description of the invention. Then add malonic acid and mix for 2-3 hours, after which the analysis is carried out. Technical characteristics of the obtained composition in comparison with the well-known adhesive company "Anles" are shown in table 1.

Table 1. Clay "Anles" S. Petersburg The inventive adhesive composition 1. Appearance - a uniform transparent liquid with a pungent odor of acetone 1. Appearance - homogeneous transparent liquid 2. Brookfield viscosity - 2200 cf. 2. Brookfield viscosity - 3020 sr 3. The dry residue of -18.0% 3. The dry residue is 18.0% 4. Delamination strength: 4. Delamination strength: 1) Kirza + leather jacket 1) Kirza + leather jacket b / w 1 min - 18.6 n / cm b / w 1 min - 30.4 n / cm b / w 24 hours - 40.8 n / cm b / w 24 hours - 53.2 n / cm 2) PVC + PVC b / w 1 min - 32.8 n / cm 2) PVC + PVC b / w 1 min - 39.5 n / cm

As can be seen from the example, the inventive adhesive composition has high technical characteristics.

Thus, the proposed invention allows to obtain an environmentally friendly adhesive composition having good technical and operational characteristics.

Claims (3)

1. An adhesive composition based on a mixture of ester urethane rubbers of the Desmocoll series, containing stabilizing additives — malonic acid and tinuvin, a solvent characterized in that it additionally contains a target additive of aerosil, and the base of the adhesive composition is a mixture of ester urethane rubbers Desmocoll-540 / 4 "," Desmocoll-540/2 "and" Desmocall-406 "in the following ratio of components, wt.%:
Ester urethane rubber Desmocoll-540/4 12-16 Ester urethane rubber Desmocoll-540/2 1-3 Ester urethane rubber Desmocoll-406 0.5-1.5 Aerosil 0.2-1 Malonic acid 0.1-0.2 Tinuvin 0.05-0.08 Solvent Rest 2. The adhesive composition according to claim 1, characterized in that the solvent contains a composition comprising acetone, ethyl acetate, toluene in the following ratio, wt.%:
Acetone 58-74 Ethyl acetate 2-10 Toluene 4-8 3. The adhesive composition according to claim 1, characterized in that it contains Aerosil 200, Tinuvin B75.