FI109707B - Glue - Google Patents

Description

109707

GLUE - LIM

The present invention relates to an adhesive for bonding articles and products made of water-insoluble, synthetic, organic polymers such as hard or soft PVC, ABS, polycarbonate, polystyrene, polyacrylamide. The adhesive contains as a binder a water-insoluble synthetic organic polymer selected from the group consisting of PVC, ABS, polyacrylate, polycarbonate, cellulose acetate, polyacrylamide, polyamide and polystyrene or homo- and copolymers of these mixtures, and a solvent. In the adhesive, a mixture of low molecular weight diesters (basic esters) of organic dicarboxylic acids is used as a solvent, optionally together with a 5 membered lactam. The adhesive of the present invention is environmentally safe, hygroscopically stable, and provides high strength adhesive seams. The invention also relates to a method of producing an adhesive seal between the surfaces of the products of the aforementioned polymers, wherein at least one of the surfaces to be bonded is applied an adhesive according to the invention.

European Patent Publication EP 0 111 250 B2 discloses a method of making an adhesive seam wherein the PVC products are bonded using one or more of: 5 or 6 membered water-miscible lactones or *. · · · · · · · · · · · · · · · · · ·: · · · · · · · · · · · · · · · · Adhesive solution of a polymer such as PVC, ABS, polyacrylate and the like, if desired together with common additives such as thixotropic and / or , to get PVC pipes when gluing ·,: adhesive seams that are reported to be leak tight and 35 good quality. N-methyl-2-pyrrolidone (NMP) is mentioned as the preferred lactam-type solvent and gamma-butyrolactone as the preferred * .l.-lactone type solvent.

109707 2

European Patent Publication No. 0 046 957 B1 discloses a method for reducing solvent vapor when applying an adhesive containing organic solvents, characterized in that 0.1 to 20% by weight of the solvent is replaced by N-alkylpyrrolidone, in particular N-methyl-2-pyrrolidone. The solvents to be replaced are those containing dimethylformamide, tetrahydrofuran, dioxane, hydrogen chloride, esters such as amyl and butyl acetate and also aromatics such as to-10-lylene or xylene and ketones such as acetone, methyl-ethyl ketone and especially cyclohexanone.

The present invention relates to an adhesive, characterized in that it has a composition according to claim 1.

15

The present invention thus relates to a mucus wherein the solvent contains one or more small molecular esters of organic dicarboxylic acids, with the proviso that if the solvent contains dimethyl adipate, the solvent is a mixture of several small molecular esters of organic dicarboxylic acids. Optionally, the adhesive also contains a 5-member, water-miscible, lactam to glue products to themselves or to each other made of hard or soft PVC, ABS, polycarbonate, polystyrene. 25 Rene, Polyacrylate, Polyacrylamide.

The invention also relates to a method for making glued seam. which is defined in the patent claim 8 /.

In the process of the invention, an adhesive seam is prepared from water-insoluble, synthetic, organic polymers such as hard or soft PVC, ABS, polycarbonate, polystyrene, polyacrylate. 35, polyacrylamide products, by applying an adhesive according to the invention containing at least one PVC, ABS, in a solvent comprising one or more organic dicarboxylic acid • 109707 3 low molecular weight basic esters, water-insoluble, synthetic organic homo- or copolymer of polyacrylate, polycarbonate, cellulose acetate, polyacrylamide, polyamide or polystyrene, at least one of the surfaces to be joined together, which surfaces are then brought together and dried.

The adhesive according to the invention is suitable, for example, for bonding high pressure and low pressure pipes for drinking water and waste water, PVC roof gutters, PVC roof membranes, soft PVC hoses for PVC and bathroom PVC and similar PVC for joining existing floor sections and siding 15.

PVC, ABS, polyacrylate, polycarbonate, cellulose acetate, polyacrylamide, polyamide or 20 polystyrene water-insoluble synthetic organic homo- or copolymer is used as the binder in the adhesive of the present invention. Said polymer is suitably used as a binder in an amount of 5 to 60% by weight, preferably 10 to 50% by weight, and most preferably 10 to 20% by weight, based on the total size of the adhesive. The basic ester mixture is conveniently contained in the adhesive 25 in an amount of 10-95% by weight, preferably 30-90% by weight. and preferably 50-90% by weight based on the total size of the adhesive.

«· ·! . When 5-membered lactam is used, N- '/ methyl-2-pyrrolidone (NMP) is preferably used, which is suitably used up to 50% by weight based on the total size of the adhesive.

* · ·

The viscosity of the adhesive can be adjusted over a wide range; '·· by increasing or decreasing the concentration of the binder polymer or polymers in the adhesive. In addition, a thickener or a thixotropic agent such as colloidal silica may be added, if desired, in an amount of up to 10% by weight.

109707 4

Suitable binders for use in the adhesive composition of the present invention are PVC polymers, for example from Vinnol Wacker-Chemie GmbH or Vestolit Hiils AG, and PVC copolymers such as Genchlor 700 from ICI.

Other suitable binders for use in the adhesive composition of the invention include, for example, acrylic resins such as Elvacite 2042 from Du Pont, polycarbonate, cellulose acetate, polyacrylamide, polyamide and polystyrene.

10

Preferably, one or more small molecular diester (basic esters) of organic dicarboxylic acids such as oxalic acid and its homologues are used as a solvent in the adhesive composition of the invention. Especially suitable are esters of succinic acid, glutaric acid and adipic acid, in particular dimethyl esters of these acids. A suitable mixture for use as a solvent in the adhesive composition of the present invention is a mixture of dimethyl succinate, dimethyl glutarate and dimethyl adipate such as Estiplast 150 from Estichem A / S.

The adhesive composition of the present invention may also contain common additives such as stabilizers, thickeners, thixotropic agents, etc., preferably in an amount of up to 15% by weight, in particular 2 to 10% by weight.

»» ·! . The composition of a typical composition of the present invention may be as follows ;;;; 30 · 15 parts of PVC copolymer (eg Genchlor 700)

40 parts of basic esters (for example Estiplast 150) 40 parts of N-methyl-2-pyrrolidone: 35 (NMP)

Common PVC Stable 3 Parts 1Sensors 109707 5

Thixotropic agent in 3 parts (e.g. pyrogen, silica, Aerosil 200).

The invention of the present invention achieves several advantages over the prior art, as evidenced, for example, by the above-mentioned EP-A-0 111 250 B2. The adhesive of the present invention is much more environmentally safe. Using the adhesive of the present invention provides a non-hygroscopic adhesive seal which is instead made using an adhesive containing N-methyl-2-pyrrolidone (NMP) as the solvent. Further, the use of an adhesive of the present invention wherein only one or more of the basic esters or a mixture of the basic esters and 15 NMP is used as the solvent further provides an adhesive seal having a higher strength than using only NMP as the solvent. In contrast to adhesives whose solvents are exclusively based on NMPr, the invention provides an adhesive which does not reduce the strength properties of the adhesives by acting as a plasticizer for the materials.

The invention will be further described by the following examples, which, however, are not intended to limit the invention in any way.

Example 1: In a sealed container, 15 g of PVC copolymer (Genchlor 700 Imperial Chemical Industries; East, UK) are dissolved in a mixture of 42.5 g of N-methyl-2-pyrrolidone '· · (NMP) and 42.5 g of a mixture of the basic esters, namely dimethyl · 30 · luccinate, dimethyl glutarate and dimethyl adipate ·.

35 Example; In a sealed container, 20 g of an acrylic copolymer (Elvacite 2042 from Du Pont) is dissolved in a mixture of 80 g of the same basic esters as in Example 109707 6 L under vigorous stirring until a homogeneous solution is obtained.

Example 3r In a sealed container, 20 g of acrylic-5 copolymer (Elvacite 2042) is dissolved in a mixture of 40 g of NMP and 40 g of the same mixture of the basic esters as in Example 1 with vigorous stirring until a homogeneous solution is obtained.

Example 4: 15 g of PVC are dissolved in a sealed container

(Vinnol E type, having a K value of about 60 from Wacker-Che mie) to a mixture of 35 g of NMP and 50 g of the same type of basic ester as in Example 1 with vigorous stirring until a homogeneous solution is obtained.

15

Example 1: In a sealed container, 15 g of a PVC copolymer (Genchlor 700) is dissolved in a mixture of 85 g of NMP under vigorous stirring until a homogeneous solution is obtained.

20

Example_5_L 15 g of PVC are dissolved in a sealed container

copolymer (Genchlor 700) to a mixture of 41.5 g of NMP and 41.5 g of the same basic ester mixture as in Example 1 with vigorous stirring until a homogeneous solution is obtained. Thereafter, 2 g of pyrogen silicon dioxide (from Aerosil 200 Degussa) are added.

; Example 6: In a sealed container, 15 g of polystyrene (Amoco 18-290 from Amoco Chemical) is dissolved in a mixture of 30 42.5 g of NMP and 42.5 g of the same mixture of the basic esters as in Example 1 with vigorous stirring until homogeneous solution.

Example 7: The strength of the adhesive joints made with the adhesives made in Examples 1-3 and 5 and in Comparative Example *, 35 L was measured by gluing two hard pieces of "rigid" PVC. The overlap was 2.25 cm 2.

109707 7

Strength is given as shear strength of 1 resp. After a drying time of 24 hours.

L, j ima Strength after 1 hour Strength after 24 hours 5

Example 1540 N 900 N

Example 2 310 N 840 N

Example 3 220 N 375 N

comparative

10 marks 1,530 N 695 N

Example 5 670 N 1020 N

KRimprkki 8: All adhesive types in Examples 1-6 and Comparative Example 1 were subjected to tests to assess hygroscopicity. Drops of glue were applied to the black plate. After 24 hours at 23 ° C and 50% relative humidity, the appearance of the droplets was evaluated to determine their tendency to bleach. Only sample from Comparative Example 1 showed a strong tendency for moisture to absorb absorber-20 and thus to bleach. Instead, all of the adhesive compositions from the other examples were clear and transparent.

Example 9 This example shows that an adhesive according to the invention based on a mixture of NMP and basic esters: is more environmentally friendly than an adhesive based solely on NMP.

• »» '. · According to Scandinavian environmental legislation, the solvent is · 30 characterized by its YL value. The YL value is the 'amount of air to be used to dilute the vapors from 1 liter of solvent to a level below the maximum occupational exposure limit.

\ 35 YL coefficient = K x 10,000 (mg) / MAK (mg / m3) * - * »109707 8 K depends on the vapor pressure of the solvent and is 0.3 for NMP and 0 for basic esters.

The MAKs are 400 mg / m3 for NMP and 0 for basic 5 esters.

This results in a YL of 8 for NMP and 0 for mixtures of basic esters.

10 Required air demand is m3 air / liter product = UN factor x% solvent x product density.

The adhesives used in the examples have a density close to 1 15 kg / liter.

The sum of the values of the solvents used is summed up. The lower the amount, the more eco-friendly.

20 This results in a comparison test adhesive of 85 x 8 = 680.

The glue in Example 1 gets a value of 43x8 + 43x0 = 344.

. ·. It follows that the adhesive of the present invention; the environmental impact is smaller.

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Claims (12)

109707 Patent Claims: 1. An adhesive for bonding plastic articles containing as an adhesive a water-insoluble synthetic organic polymer selected from PVC, ABS, polyacrylate, polycarbonate, cellulose acetate, polyacrylamide, polyamide and polystyrene, or mixtures thereof. homo- and copolymers, and a solvent, characterized in that the solvent contains one or more low molecular weight esters of organic dicarboxylic acids, with the proviso that if the solvent contains dimethyl adipate, the solvent is a mixture of low molecular weight esters of organic dicarboxylic acids. Adhesive according to Claim 1, characterized in that it contains from 5 to 60% by weight of one or more water-insoluble synthetic organic polymers, based on the total size of the adhesive, and 10-95% by weight of one or more low molecular weight esters of organic dicarboxylic acids , calculated on the size of the adhesive. Adhesive according to Claim 1 or 2, characterized in that the adhesive additionally contains up to 50% by weight of 5-membered lactam, based on the total adhesive, as solvent. 25 na. I | Adhesive according to any one of the preceding claims,! . characterized in that it contains as a solvent a mixture of low molecular weight esters of organic dicarboxylic acids selected from the group consisting of esters of oxalic acid and its homologs. Adhesive according to claim 4, characterized in that the mixture of low molecular weight esters of organic dicarboxylic acids is selected from the esters of succinic acid, glutaric acid and adipic acid. t 109707 Adhesive according to claim 5, characterized in that the mixture of low molecular weight esters consists of a mixture of dimethyl succinate, dimethyl glutarate and dimethyl adipate. 5 Adhesive according to one of Claims 3 to 6, characterized in that the solvent in the form of a 5-membered lactam contains N-methyl-2-pyrrolidone (NMP). 8. A method for producing an adhesive seam between surfaces of hard and soft PVC, ABS, polycarbonate, polystyrene, polyacrylate and polyacrylamide made from water-insoluble synthetic organic polymers, characterized in that the method comprises: at least one water-insoluble, or water-insoluble, homogeneous copolymer of at least one organic soluble or water-insoluble organic solvent of at least one PVC, ABS, polyacrylate, polycarbonate, cellulose acetate, polyacrylamide, polyamide or polystyrene in a solvent comprising a low molecular weight ester of organic dicarboxylic acids to one of the surfaces to be joined. A process according to claim 8, characterized in that the adhesive contains as a solvent a mixture of small molecular esters of organic dicarboxylic acids: selected from esters of oxalic acid and its homologues; . ta. i * t »I I · 10. A method according to claim 8 or 9, characterized in that the adhesive additionally contains a 5-membered lactam as a solvent. i »f t The method according to claim 10, characterized in that N-methyl-2- * pyrrolidone is used as the 5-membered lactam in an amount up to 50% by weight of the adhesive. * · I t I »109707 Process according to any one of the preceding claims, characterized in that an adhesive is used which contains 5 to 60% by weight of a polymer binder and 10 to 95% by weight of one or more small molecule esters of organic dicarboxylic acids as a solvent.