USE OF COMPOUNDS HAVING N 2-OXO-1,3-DIOXOLANE-4-CARBOXAMIDE UNITS IN TWO-COMPONENT ADHESIVES

Abstract

A description is given of the use of compounds having n 2-oxo-1,3-dioxolane-4-carboxamide units as a reactive component in 2-component adhesives, especially for preparing hydroxypolyurethanes or hydroxypolycarbonates for adhesives applications, where n is a number greater than or equal to 2. A description is also given of corresponding two-component adhesives and adhesive bonding methods. Employed preferably as a second component of the two-component adhesive is a polyfunctional curing agent compound which is preferably selected from polyamines which have two or more amine groups and polyols which have two or more alcoholic hydroxyl groups.

Claims

1. A method for preparing a two-component adhesive, the method comprising: introducing a compound having n 2-oxo-1,3-dioxolane-4-carboxamide units as a reactive component into the two-component adhesive, where n is a number greater than or equal to 2.

2. The method according to claim 1, wherein the compound having n 2-oxo-1,3-dioxolane-4-carboxamide units is represented by formula (I) ##STR00020## where R.sub.1 and R.sub.3 independently of one another are H or an organic radical; and R.sub.2 is an n-valent organic radical which is substituted by n1 further 2-oxo-1,3-dioxolane-4-carboxamide groups, and n is a number greater than or equal to 2.

3. The method according to claim 2, wherein in the formula (I) R.sub.1 is H, a straight-chain, branched or cyclic C.sub.1-12 alkyl group, a C.sub.6-10 aryl group, a C.sub.6-12 arylalkyl group, or a C.sub.6-12 alkylaryl group; and R.sub.3 is H or a straight-chain, branched or cyclic C.sub.1-12 alkyl group.

4. The method according to claim 2, wherein R.sub.1 in the formula (I) is H, a straight-chain, branched or cyclic C.sub.1-12 alkyl group, a C.sub.6-10 aryl group, a C.sub.6-12 arylalkyl group, or a C.sub.6-12 alkylaryl group, R.sub.3 in the formula (I) is H, an aryl group, or a straight-chain, branched or cyclic C.sub.1-12 alkyl group which optionally comprises O or N; and R.sub.2 in the formula (I) is an n-valent radical which is substituted by n1 further 2-oxo-1,3-dioxolane-4-carboxamide groups of formula (II) ##STR00021## where R.sub.3 is H, an aryl group, or a straight-chain, branched or cyclic C.sub.1-12 alkyl group which optionally comprises O or N; and n is a number greater than or equal to 2.

5. The method according to claim 1, wherein n is 2 to 5.

6. The method according to claim 1, further comprising: introducing a polyfunctional curing agent compound into the two-component adhesive, wherein the curing agent is selected from the group consisting of a polyamine which has two or more amine groups and a polyol which has two or more alcoholic hydroxyl groups.

7. The method according to claim 6, wherein at least one of the compound having n 2-oxo-1,3-dioxolane-4-carboxamide units and the curing agent compound comprises at least one linear or branched spacer group having a molecular weight of at least 200 g/mol.

8. The method according to claim 2, wherein R.sub.2 in the formula (I) is a linear or branched C.sub.2 to C.sub.22 alkylene group; a polyether group of formula -(A-O).sub.m, where A is C.sub.2 to C.sub.5 alkylene and m is a number from 1 to 100; a polycarbonate group; a polyester group; or a poly(meth)acrylate group.

9. The method according to claim 1, wherein the compound having n 2-oxo-1,3-dioxolane-4-carboxamide units is selected from the group consisting of a compound of formula (III) ##STR00022## where n is a number from 1 to 12; a compound of formula (IV) ##STR00023## where y is a number from 1 to 12; a compound of formula (V) ##STR00024## a compound of formula (VI) ##STR00025## where n is a number greater than or equal to 0; and a compound of formula (VII) ##STR00026## where ##STR00027## is an alkoxylated glycerol radical.

10. A two-component adhesive, comprising at least one compound having n 2-oxo-1,3-dioxolane-4-carboxamide units as a reactive, first component; and at least one curing agent compound selected from the group consisting of a polyamine having two or more amine groups and a polyol having two or more alcoholic hydroxyl groups as a second component, wherein n is a number greater than or equal to 2.

11. The two-component adhesive according to claim 10, which at a temperature of 70 C. or below has a Brookfield viscosity of less than 10 000 mPa s, measured at 12 rpm with spindle 3.

12. The two-component adhesive according to claim 10, wherein peel strength of two polyester films bonded to one another with a 3 m layer of the adhesive and with an applied pressure of 3 bar is greater than 1.5 N/15 mm after 24 hours.

13. The two-component adhesive according to claim 10, further comprising at least one catalyst for catalyzing the reaction of cyclocarbonate groups with the functional groups of the curing agent.

14. A method for bonding two substrates to one another, the method comprising: applying a two-component adhesive to a surface of at least one of the substrates, wherein the two component adhesive comprises at least one compound having n 2-oxo-1,3-dioxolane-4-carboxamide units as a reactive component, and n is a number greater than or equal to 2.

15. The method according to claim 14, comprising applying the two-component adhesive to a first substrate provided in a form of a first film and/or to a second substrate provided in a form of paper, a record film which is identical to or different from the first film, or a molding, optionally allowing the adhesive to dry, and laminating the first substrate onto the second substrate optionally with thermal activation.

16. A film-laminated article, produced by the method according to claim 15.

17. A 2-oxo-1,3-dioxolane-4-carboxamide of formula (I) ##STR00028## where R.sub.1 and R.sub.3 independently of one another are H or an organic radical; and R.sub.2 is an n-valent organic radical which is substituted by n1 further 2-oxo-1,3-dioxolane-4-carboxamide groups, n is a number greater than or equal to 2, and where between the 2-oxo-1,3-dioxolane-4-carboxamide groups there is at least one linear or branched spacer group having a molecular weight of at least 200 g/mol.

18. The 2-oxo-1,3-dioxolane-4-carboxamide according to claim 17, wherein R.sub.2 in the formula (I) is a linear or branched C.sub.2 to C.sub.22 alkylene group; a polyether group of formula -(A-O).sub.m, where A is C.sub.2 to C.sub.5 alkylene and in is a number from 1 to 100; a polycarbonate group; a polyester group; or a poly(meth)acrylate group.

19. The 2-oxo-1,3-dioxolane-4-carboxamide according to claim 17, which is a compound of formula (IV) ##STR00029## where y is a number from 1 to 12; or a compound of formula (VII) ##STR00030## where ##STR00031## is an alkoxylated glycerol radical.

Description

EXAMPLES

Example 1: Compound Having Three 2-oxo-1,3-dioxolane-4-carboxamide Groups, Based on Ethoxylated/Propoxylated Glycerol

[0108] ##STR00017##

##STR00018##

=glycerol plus EO/PO
M.sub.eq=1870 g/mol (molecular weight per cyclocarbonate group)

[0109] Under a nitrogen atmosphere, 13.94 g of toluene 2,4-diisocyanates (TDI) (0.0825 mol) and 10.56 g of 2-oxo-1,3-dioxolane-4-carboxylic acid (0.08 mol) are dissolved in 70 ml of dry THF or acetone. 0.12 g (1 mol %) of 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU) is added and the reaction mixture is stirred at room temperature for 12 hours. Removal of the solvent by evaporation gives the product as a white solid in quantitative yield.

[0110] The reaction may also take place in dry acetonitrile and with 4-DMAP as catalyst.

[0111] In the presence of DBTL (dibutyltin dilaurate, 0.02% by weight), the product obtained may be reacted with Lupranol 2095 (trifunctional polyether polyol having primary hydroxyl end groups) to give a difunctional prepolymer. For this purpose 5.0 g (0.0195 mol) of the product are dissolved in dry THF, and 31.2 g of Lupranol 2095 (6.52 mmol) and 1.2 mg of DBTL (0.002 mmol) are added. The reaction mixture is heated at 60 C. for 4 hours. Removal of the solvent by evaporation gives the product in the form of a viscous yellow oil.

Example 2

Compound Having Three 2-oxo-1,3-dioxolane-4-carboxamide Groups, Prepared from Glycerol Carbonate Carboxylic Acid (2-oxo-1,3-dioxolane-4-carboxylic Acid) and isocyanurate-modified hexamethylene diisocyanate (Basonat HI 100)

Basonat HI 100:

[0112] ##STR00019##

[0113] 31.79 g of cyclocarbonate carboxylic acid (0.12 mol) in 80 ml of THF were introduced as an initial charge, giving a yellow solution. 0.3704 g of DMAP (4-(dimethylamino)-pyridine, 0.0012 mol) in 60 ml of THF was added. This was followed by the addition of 46.09 g of Basonat HI100 (0.12 mol based on NCO; the NCO number of Basonat HI 100 is 21.9%) in 80 ml of THF. This solution is stirred at room temperature for around 24 hours. The solution becomes cloudy overnight. Following removal of the THF by evaporation on a rotary evaporator, there remained 73.76 g of a yellow liquid of high viscosity. There was no NCO peak visible in the IR spectrum, and the NCO number was 1.1%.

Example 3: Two-Component Adhesives

[0114] The 2-oxo-1,3-dioxolane-4-carboxamides of example 1 and of example 2, respectively, were dissolved in THF at 23 C. and blended with different aminic hardeners (see table 1).

[0115] Immediately after mixing, the resultant reactive two-component adhesive was applied in a layer thickness of 3 m to a printed polyester film 36 m thick. The solvent was evaporated by means of a stream of hot air and then, in a calender, a second polyester film 36 m thick, treated beforehand by corona, was laminated onto the layer of adhesive under a pressure of 3 bar. The resulting laminate was cut into strips 15 mm wide, and the peel strength of these strips was determined at room temperature (20 C.) after 24 hours [N/15 mm]. This was done using a tensile testing machine, with the peel strength test conducted at a tensile angle of 90 (T test). The results are reproduced in table 1.

Aminic Hardeners:

[0116] DODDA: 4,9-dioxadodecane-1,12-diamine [0117] H.sub.2NCH.sub.2CH.sub.2CH.sub.2OCH.sub.2CH.sub.2CH.sub.2CH.sub.2OCH.sub.2CH.sub.2CH.sub.2N H.sub.2
DATOTD: 1,13-diamino-4,7,10-trioxatridecane [0118] H.sub.2NCH.sub.2CH.sub.2CH.sub.2OCH.sub.2CH.sub.2OCH.sub.2CH.sub.2OCH.sub.2CH.sub.2CH.sub.2N H.sub.2
DAP: 1,3-diaminopropane, H.sub.2NCH.sub.2CH.sub.2CH.sub.2NH.sub.2

TABLE-US-00001 TABLE 1 Adhesive compositions and results of the peel strength measurements Peel 2-Oxo- strength 1,3-dioxolane- Aminic 24 h Example 4-carboxamides hardener [N/15 mm] 3.1 1872 g example 1 102 g DODDA 3.1 3.2 1872 g example 1 110 g DATOTD 4.5 3.3 1872 g example 1 37 g DAP 3.3 3.4 280 g example 2 240 g Polyetheramine 3.4 D 400 3.5 280 g example 2 37 g DAP 0.3 3.6 40 g Liofol 60 g Liofol 3.6 Comparative UR7732 UR 6084 Liofol UR7732/Liofol UR 6084: two-component polyurethane laminating adhesive composed ofisocyanate-based binder (Liofol UR7732) and polyol hardener (Liofol UR 6084)

[0119] Especially suitable for industrial usefulness is a peel strength of greater than 1.5 N after 24 hours for applications of the adhesive in flexible packaging and for composite film lamination.