DE2144492A1 - ADHESIVE FOR BONDING MATERIALS - Google Patents

Description

2H4492

SCHERING AG

Patent department

Axen / jBu

Adhesive for bonding materials

Addition to DBP (patent application P 21 18 797-3).

The invention relates to the further development of the use of solutions of polyester urethanes as an adhesive for bonding materials, especially those containing soft maize Plastics made from polyvinyl chloride or its copolymers according to additional patent (patent application

P 21 18 7 ^ 7.3) to the main patent (patent application

P 20 32 276.3), in which the polyester urethanes in the melt or reaction products prepared in solution are off

A) Diisocyanates, especially the aromatic series, in an at least stoichiometric amount, based on the total hydroxyl number of the compounds mentioned under B), preferably with an excess of about $ 5 over the stoichiometric amounts, and off

B) bifunctional hydroxyl compounds, namely from

1. bifunctional mixed polyesters based on caprolactone and straight-chain alkanedicarboxylic acids with 6 to 12 carbon atoms and straight-chain alkanediols having 4 to 12 carbon atoms with one Hydroxyl number between 30 and 100, or off

2. bifunctional mixed polyesters based on hydroxyeapronic acid, straight-chain alkanedicarboxylic acids with 6 to 12 carbon atoms and straight-chain alkanediols with 4 to 12 carbon atoms with a Hydroxyl number between 30 and 100, or off

3 0 9 812/1001

-2-

SCHERING AG

Patent department

Ax / Bu -2-

3. Mixtures of the hydroxyls mentioned under 1. and 2.. connections, and off

4. 0.1 to 0.5 mol, especially 0.2 mol, of an alkanediol with 2 to 6 carbon atoms per mole of polyester,

which is characterized in that as a basis for the bifunctional Mixed polyesters instead of caprolactone or hydroxycaproic acid, poly-6-caprolactone or poly-to-hydroxycaproic acid is used.

The German Auslegeschrift 1 256 822 already mentions the use of melts or solutions of reaction products of diisocyanates and esterification products from alkanedicarboxylic acids with at least six carbon atoms and alkanediols having at least four carbon atoms as Adhesives for bonding plastics containing plasticizers known from polyvinyl chloride or its copolymers with itself or any other materials.

These products show good adhesion to PVC up to a maximum plasticizer content of approx. 50 $. At higher temperatures, eg 5O ⁰ C, the bond values fall very strongly and show at 8O ⁰ C no adhesive effect. An improvement in the heat resistance of the bonds can then only be achieved by adding triisocyanates with a corrosive effect. The use of such isocyanate-containing two-component solutions is disadvantageous, firstly with regard to manual handling and secondly with regard to the limited pot life of the adhesive solution and, in particular, the time-limited heat reactivability.

-3-309812 / 1001

2H4492

SCHi) RING AG

Patent department

Ax / Bu -3-

From the German Offenlegungsschrift 1 930 336 is the ■ Use of hydroxyl-containing polyurethanes with a molecular weight of over 50,000 is known from diisocyanates and a) containing hydroxyl groups Polyesters with a molecular weight of more than 2000 from alkanedicarboxylic acids with at least 6 carbon atoms and alkanediols with at least 4 carbon atoms or b) polyesters with a molecular weight of more than 2000, such as by polycondensation of hydroxyalkanemonocarboxylic acids having at least 5 carbon atoms or by polymerization their lactones are obtained, in both cases up to 0.7 mol of an alkanediol having at least 4 carbon atoms per mole of polyester are used as chain extenders for the preparation of solvent-containing Adhesives.

Polyester urethanes based on mixed polyesters are due to the inventors of the German Offenlegungsschrift 1,930,336 The inconsistent structure has evidently been viewed as unsuitable. But it has been found that the invention Polyester urethanes based on the identified mixed polyesters are particularly advantageous.

Mixed polyesters made from caprolactone, polyols and dicarboxylic acids and their production have already been described (German Offenlegungsschriften 1 940 942 and 1 946 430).

In the German Offenlegungsschrift 1 940 942 the production of liquid misclipolyesters based on ε-caprolactone or 6-hydroxycaproic acid, a dicarboxylic acid or their anhydride, a glycol in an excess of 5 to 20 Gow .- $ and a polyol with at least 3 Hydroxide groups described in the molecule.

309812/1001

SCHERING AG

Patent department

Ax / Bu -4-

The polymerization of these 4 components "is performed at a temperature of 220" to 240 ⁰ C in the presence of letraalkyltitanat as a catalyst and a solvent and / or entrainer, in which the catalyst residues are undesirable in a re-use "of the product and therefore not required catalysis must become. ' .

In the German Offenlegungsschrift 1 946 430 liquid Hydroxyl group-containing mixed polyesters described. For their production is ε-caprolactone in the presence of a Ion exchange resin bearing sulfonic acid groups with a large excess of water to form 6-hydroxycaproic acid hydrolyzed.

Thereafter, a dicarboxylic acid and a mixture of two different dialcohols in excess of 5 is added to 20 wt .- ^, stripped under considerable expense (at 230 °), the added water and then with the addition of a further catalyst (tetraalkyl titanate) at 250 ⁰ C the polymerizing esterification carried out.

For further processing, the reaction mixture has to be dehydrated in another apparatus with heating in vacuo and be degassed.

In order to obtain a product with the desired properties, a polyalcohol must also be used during manufacture with at least 3 OH groups per molecule can be used.

Has opposed both of the above-mentioned disclosure documents the production of the mixed polyesters, which serve as the basis for the polyurethanes according to the invention, a number of

-O-

SCHERING AG

Patent department

Ax / Bu -5-

Advantages:

1. It is not necessary to use a dialcohol mixture.

2. No additional polyalcohol is required.

3. No excess of dialcohol is required, which must then be removed and / or during the reaction is lost because the temperature is too high.

4. You can work without a catalyst.

In the German Offenlegungsschrift 1 ~> 55 902 Block polyester polyols described, which by polyaddition of lactones, in particular ε-caprolactone, to polyester diols or polycarbonate diols are obtained.

These products are different from those of the present invention both in structure and in production lying mixed polyester.

Purely for the production of caprolactone polyesters and polyhydroxyeapronic acids Customary methods come into consideration, for example in the German Offenlegungsschriften 1 420 778 and 1 914 458 and in the German Auslegeschriften 1 213 995, 1 247 019 and 1 936 587 are.

According to one that does not belong to the known state of the art The proposal is ε-caprolactone in the presence of an antimony (Y) halide or a Trialkyloxoniura salt as a catalyst, optionally using a dialcohol as a ring-opening agent, to form an OH group at the chain ends

309812/1001

-6-

2UA492

SCHERING AG

Patent department

Ax / Bu -6-

polymerized load-bearing polyester. According to the same proposal, the catalyst is then reduced by a low Amount of water decomposes. In the case of the antimony (V) halides and the trialkyloxonium hexahalogenoantimonate (V) by the water antimony (V) oxide hydrate, which in a subsequent heat supply, optionally with supply a small amount of a mono-, di- or polyalcohol, the esterification of the still free carboxyl groups catalyzed. According to the same proposal, the catalyst and its residues are optionally removed from the usual filtration in the presence of bleaching earth and / or activated carbon, the reaction product is completely removed.

The oxycaproyl units of polycaprolactones and polyhydroxycaproic acids can be partially substituted by lower alkyl groups.

The preparation according to the invention required mixing polyester may by methods known per se, for example, hydroxycaproic acid, poly-cue by thermal esterification of the individual components, polycaprolactone diol or, alkane diol and alkane dicarboxylic acid, at temperatures from 100 to 280 C, preferably between 120 and 250 ⁰ C done . The use of polycaprolactone diol or polyhydroxycaproic acid instead of the monomers has proven advantageous in terms of process technology.

Through the use of commercially available polycaprolactone diols (e.g. Niax D 560, D 510 from Union Carbide Corp.) or polyhydroxycaproic acids, which are already in a sufficiently pure form, the production of mixed polyesters can be considerably simplified, as the cleaning stage can usually be omitted.

309812/1001

-7-

SCHERING AG

Patent department

Ax / Bu -7-

Depending on. Molecular weight and amount of the polycaprolactones used the polyurethane adhesives produced using the mixed polyesters can have different properties, such as viscosity give the solution, initial adhesion to materials and heat resistance of the bond.

The mixed polyesters according to the invention are based on polycaeprolactone diols from the molecular weight between approx. 200 and 2000.

The mixed polyesters required according to the invention should have an OH number of 30 to 100, preferably 30 to 60.

The alkanediols are those with 4 to 12 carbon atoms, e.g. 1,6-hexanediol, and the alkanedicarboxylic acids are those with 6 to 12 carbon atoms, e.g., adipic acid, use.

The esterification times can be significantly shortened, the reaction temperatures can be reduced, and the azeotropic removal of the water with towing means becomes superfluous, and the 5 to 20% glycol excesses usually used (over the billed amount) can be reduced significantly (preferably to $ 1 of the billed amount) or even completely omitted. The procedure described here is generally applicable.

The mixed polyesters containing hydroxide groups prepared by the process described can be converted into polyurethanes, such as those according to the invention, because of their low or no content of catalyst residues in solution. For the reaction of the hydroxide-containing polyester with isocyanates in the melt, cleaning with bleaching earth may be necessary, ie the polyester is heated with active bleaching earth (approx. 1 - 2 ^a / o) for a few hours

309812/1001

-ö- BATHROOM 0Rigi _Nal

SCHERING AG

Patent department

Ax / Bu -8-

treated and then filtered off.

The ratio of poly-e-caprolactiondiol or poly-ü) -hydroxycaproic acid to dicarboxylic acid / diol can be varied within the limits 5:95 to 95: 5.

A special one too. economic considerations beneficial Ratio is around 10:90.

As alkanediols to be used in the production of polyurethane With 2 to 6 carbon atoms, ethylene glycol, butanediol and hexanediol are particularly suitable.

Examples of suitable diisocyanates include hexamethylene diisocyanate, tolylene diisocyanate, 1,4-cyclohexane diisocyanate, 4 »4'-diisocyanatodiphenylmethane.

The mixed polyesters to be used according to the invention are reacted with the diisocyanates in a manner known per se Way by reacting in the solution or in the melt. The reaction is continued until a highly viscous one Phase is reached. This is followed by a post-reaction with the addition of suitable solvents, e.g. toluene or ethyl acetate, or a post-maturation process of the melt outside the reactor. The particular advantage of this procedure is that catalysts are avoided, their whereabouts in the process products are disadvantageous affects without extending the response time will. In addition, the formation of gel particles, which can occur in the usual post-ripening process, is avoided.

It is also possible to add portions of inert solvents before the highly viscous phase is reached. The invention Polyester urethane adhesives stand out against

309812/1001

-9-

2H4492

SCHERING AG

Patent department

Ax / Bu -9-

over the known adhesives of this group when processed with triisocyanate, in particular due to improved adhesive values on natural and synthetic rubber at room and elevated temperatures.

Furthermore, the polyester urethanes according to the invention show, in addition to the high adhesive values, to the abovementioned materials a comparatively better initial tack which is desirable for processing and an important one as "tack" processing feature and as a time- and pressure-dependent cohesive adhesion is to be understood.

309812 / 1QQI

21U492

SCHERIFG AG

Patent department

Ax / Bu -10-

Production of mixed polyesters for the polyether urethanes .:

Mixed polyester A

Mixed polyester from poly-cü-hydroxycaproic acid (acid number 45 »2), 1,6-hexanediol and adipic acid in a molar ratio 0.5: 9: 8

The mixture of

.1062 g of 1,6-hexanediol
1169 g adipic acid and
620 g poly-iü-hydroxycaproic acid (acid number 45.2)

is heated to 6O ⁰ G, treated with 0.05 wt .- $ ~ antimony (V) chloride and heated further. At 125 C the ¥ as £ separation begins, which is continued according to the following scheme: '

1 hour from 125 to 175 C)

1 hour from 175 to 20O ⁰ C) at normal pressure

4 hours at 20O ⁰ C)

Then allowed to about 10O ⁰ C to cool, is 10.6 g of hexane-1,6 added and allowed for 8 hours at 200 ⁰ C and 15 Torr react. A crystalline mixed polyester with the following parameters is obtained:

ber.

OH number 45.0 47.9

Acid number 0.0 1.0

For cleaning the mixing polyester is treated for about 3 hours at about 120 ⁰ C in the melt with 1 ° / o bleaching earth and is then filtered.

-11- 309812/1001

2H4492

SCHERING AG

Patent department

Axen / Bu -11-

Mixed polyester B "

Mixed polyester from poly-E-caprolactone diol, hexanediol-1,6 and, adipic acid in the molar ratio 0.7: 11.3: 11

The mixture of

600 g hexanediol-1,6 (+2 wt .- ^ excess) 181 g of poly-e-caproiactondiol (produced in the usual way from 1,6-hexanediol and ε-caprolactone in a molar ratio

1: 4) with an OH number of 184 and 724 g of adipic acid

^{is heated to 200 °} C. over the course of about 3 hours. The reaction mixture is kept for about 4 hours at 210 ° to 220 ° C. at atmospheric pressure. The esterification is then carried out over the course of 14 hours at 220 ^° C. in a water jet pump vacuum while slowly passing in nitrogen A colorless crystalline polyester with the following key figures is obtained:

ber.

OH number 38.0 40.8

Acid number 0.0 0.7

Mixed polyester C

Mixed polyester from poly-e-caprolactone diol, hexanediol-1,6 and adipic acid in the molar ratio 0.15: 11.85: 11

The mixture of

699 g hexanediol-1,6 (+ 2 wt .- ^ excess) 159 g of poly-e-caprolactone diol, type "Niax D 560" from the Union

309812/1001

—12—

2U44S2

SCHERING AG

Patent department

Ax / Bu -12-

Carbide Corp., with OH number 53 and 804 g of adipic acid

while passing in nitrogen within 3 hours to 230 ⁰ C e:

keep.

Heated 230 ⁰ C and are Gefach about 5 hours about 3 hours at this temperature already 198 ml of water (theoretical: 198 ml) was distilled off. After about 13 hours at 230 ^° C. in a water jet pump vacuum, a colorless polyester with the following parameters is obtained:

ber.

OH number 38.3 36.8

Acid number 0.0 1.3

309812 / 1JIpJ

SCHr) RIIiG AG

Patent department

Ax / Bu -13-

Mixed polyester D.

Mixed polyester from poly-e-caprolactone diol, hexanediol-1,6 and adipic acid in a molar ratio of 0.5 · s 8.5 ί 8.

The mixture of

667 g of 1,6-hexanediol (+ 2 wt. - <fo excess) 197 g of poly-ε-caprolactone diol (prepared in the usual way from 1,6-hexanediol and ε-caprolactone in a molar ratio of 1: 4) with the OH number 190 and 778 g of adipic acid

is heated ^{to 220 °} C. in about 3 hours. The reaction mixture is kept 4 hours at 220 to 23O ⁰ C under atmospheric pressure. The esterification is then completed in about 14 hours at 220 to 230 ^° C. in a water-jet vacuum while slowly passing in nitrogen. A colorless, crystalline polyester is obtained with the following key figures:

ber.

OH number 52.0 53.1

Acid number 0 0.2

-14-309812 / 1001

21U492

SCHKRING AG patent department

Ax / Bu

-14-

Examples of the production of polyester urethanes from. Mixed polyesters:

example 1

525 g of mixed polyester A are initially melted and heated to 12O ⁰ C. Within about 45 minutes, are added 51.1 g of a mixture of 80 wt .- $ 2,4-tolylene diisocyanate and 20 wt .-% of 2,6-tolylene diisocyanate and the reaction mixture stirred for about 30 minutes at 12O ⁰ C. subsequently .fügt 6.3 g of molten 1,6-hexanediol added and homogenized product for another 30 minutes at 120 C. Finally, the melt is brought about for 30 minutes at 140 ⁰ C and then transferred to a polytetrafluoroethylene-lined vessel. The reaction is completed at 140 ^° C. for 13 hours. A polyurethane with a residual isocyanate content of approx. 0.02 wt .- ^ is obtained.

The solution of the polymer (20 wt -fo in ethyl acetate / acetone, parts by weight of 1:. 1) has a viscosity of about 10 poise at 20 ⁰ C. This adhesive solution is processed by adding 5 wt .- $ of a solution of triphenylmethane 4,4 ', 4 ¹ ' -triisocyanate (20% by weight in methylene chloride).

This adhesive solution was used to create bonds with the following separation strengths, measured in kp / cm according to DIN 53 274, manufactured:

temperature 20 ⁰ C 50 ⁰ C 8O ⁰ C on the test rubber
of PVC with 48 fo "
Plasticizers 16.8
5.3 8.5
4.2 2.8
1.7

-15-

309812/1001

2HU92

SCHERING AG

Patent department

Ax / Bu

-15-

Example 2

The mixture of 500 g of copolyester B and 7.5 g of 1,4-butanediol is introduced and heated to about 12O ⁰ C. Within about 45 minutes, gives 49.0 g of a mixture of 80 wt .- $ 2,4-tolylene diisocyanate and 20 wt. -Fo 2,6-tolylene diisocyanate are added and the reaction mixture stirred for about 30 minutes at 12O ⁰ C. Finally, the heating bath is brought to 140 ^° C. and the melt is homogenized at this temperature for about 45 minutes. The product is then transferred to a vessel lined with polytetrafluoroethylene and the reaction is completed at 140 ° C. for 19 hours. A polyurethane with a residual isocyanate content of approx. 0.05 is obtained

The solution of the polymer (20 wt -φ in ethyl acetate / acetone, parts by weight 1: 1). Poise has a viscosity of 25 at 20 ° C. This adhesive solution is processed by adding 5% by weight of a solution of triphenylmethane-4,4 », 4» '- triisocyanate (20% by weight in methylene chloride). This adhesive solution was used to produce bonds with the following separation strengths (kp / cm):

temperature Example 3 20 ⁰ C 50 ⁰ C 80 ⁰ C on test rubber 13.9 7.7 1.9 ■ on PVC with 48 # 8.3 4.2 0.9 Plasticizers

The mixture of 600 g of mixed polyester C and 9 g of 1,4-butanediol is introduced and heated to about 12O ⁰ C. Within about 45 minutes, 55.0 g of a mixture of 80% by weight are added

309812/1001

-Ib-

SCHERING AG

Patent department

Ax / Bu

-16-

2,4-tolylene diisocyanate and 20 wt .- ^ 2,6-tolylene diisocyanate are added and the reaction mixture stirred for about 30 minutes at 120 ⁰ C. Finally, the heating bath is brought to 14O ⁰ C and the melt about 90 minutes at this! Temperature homogenized. The product is then transferred to a vessel lined with polytetrafluoroethylene and the reaction is completed at 145 ° C. for 20 hours. A polyurethane with a residual isocyanate content of less than 0.05% by weight is obtained. The solution of the polymer (20 wt .- $ in ethyl acetate / acetone, parts by weight 1: 1) at 20 ⁰ C poise, a viscosity of about 10 degrees.

. This adhesive solution is processed by adding 5 wt "io a solution of triphenylmethane 4,4 ^1> 4 '' triisocyanate (20 wt .- $ in methylene chloride) In order bonds were prepared with the following separation strength (kgf / cm).:

temperature 20 ⁰ C 50 ⁰ C 80 ⁰ C on test rubber
on PVC with 48 #
Plasticizers 12.6
3.8 6.6
1.5 1.4
0.4

Example 4

The mixture of 500 g of mixed polyester D and 6 g of 1,4-butanediol is introduced and heated to about 120 ⁰ C. 56.1 g of a mixture of 80% by weight of 2,4-tolylene diisocyanate and 20% by weight of 2,6-tolylene diisocyanate are added over the course of about 45 minutes. the reaction mixture is stirred for about 30 minutes at 120 ^° C. Finally, the heating bath is brought to 140 ^° C. and the melt is homogenized for about 90 minutes at this temperature

309812 / € 1 MH

SOHERING AG patent department

Ax / Bu

-17-

sated. The Uachreifung carried out for 18 hours' at 140 ⁰ C. This gives a polyurethane having a residual isocyanate content of approximately 0.05 $ The $ 20 solution of the polymer (20 wt .- $ in ethyl acetate / acetone, Gewichtsteiie. 1: 1) has a viscosity of about 45 poise at 20 ⁰ G. The adhesive solution is processed with an addition of 5 $> $ 20 a solution of triphenylmethane 4,4 ^1, 4 "-triisocyanate in methylene chloride. The separation strengths achieved in this way in kp / cm are:

temperature 20 ⁰ C 50 ⁰ C 80 ⁰ C on test rubber
on PVC with 48 JL
Plasticizers 10.4
8.7 8.6
6.1 · 3.7
2.4

-18-

309812/1001

Claims (3)

SCHERING AG patent department Axen / Bu -18- patent claim Further development of the use of solutions of polyester urethanes as an adhesive for bonding materials, in particular plasticized plastics made of polyvinyl chloride or its copolymers according to the additional patent (patent application P 21 18 797.3) to the main patent (patent application P 20 32 276.3 ), in which the polyester urethanes prepared in the melt or in solution are reaction products of A) diisocyanates, in particular of the aromatic series, in an at least stoichiometric amount, based on the total hydroxyl number of the compounds mentioned under B), preferably with. "'an excess of approx. 5 f ° over the stoichiometric amounts, and from B) bifunctional hydroxyl compounds, namely from 1. bifunctional mixed polyesters based on caprolactone and straight-chain alkanedicarboxylic acids with 6 to 12 carbon atoms and straight-chain alkanediols with 4 to 12 carbon atoms with a hydroxyl number between 30 and 100, or from 2. bifunctional mixed polyesters based on hydroxycaproic acid, straight-chain Alkandicarbon ™ acids with 6 to 12 carbon atoms and straight-chain alkanediols with 4 to 12 carbon atoms with a hydroxyl number between 30 and 100, or off 3. Mixtures of the hydroxyl compounds mentioned under 1. and 2., and from 309812/1001 2U4492 SCHERING AG Pat ent division Ax / Bu -19- 4 «0.1 to 0.5 mol, in particular 0.2 mol, of an alkanediol with 2 to 6 carbon atoms per mole of polyester, characterized in that as a basis for the bifunctional Mixed polyesters instead of oaprolactone or hydroxycaproic acid, poly-t-caprolactone or poly-to-hydroxycaproic acid is used. 309812/1001