DE19755535A1 - Binder based on oleochemical reaction products - Google Patents

Abstract

The invention relates to a bonding agent with a molecular weight of at least 1500 g per mol which is based on a reaction product of A) at least one fatty substance having an average of 1 to 6 of at least one -COOH- or acid anhydride group in the fatty radical (component A) with B) at least one average polyfunctional compound in excess, said compound being capable of reacting with the functional groups of the fatty substances (component B), and C) reacting the remaining -COOH- and the anhydride groups of this intermediate product with monofunctional compounds (component C). The invention is characterized in that the monofuctional compounds are alcohols or amines. The fatty substance is preferably comprised of a fatty radical having two C - C -double bonds and malaic anhydride. The fatty substance is preferably reacted with diols, diamines or amino alcohols such that a gelation does not occur. The remaining anhydride acid and anhydride groups are preferably reacted with monofunctional alcohols or amines. The reaction products which are obtained in such a manner are and remain thermoplastic also after being melted on repeatedly. The bonding agent are thus well suited for producing hot-melt adhesives.

Description

The invention relates to binders based on oleochemicals Reaction products and their use for gluing and sealing.

"Binder" should be understood to mean those products which are the same or connect different types of substrates or can adhere to them yourself. they are usually based on substances or mixtures of substances that are chemical and / or set physically. In addition to inorganic substances play above all organic substances play an important role and here synthetic ones high molecular weight compounds, the high molecular weight also can be achieved in stages. These substances are usually made by Additives modified so that they are more suitable for gluing and sealing. Such additives are e.g. B. resins, plasticizers, solvents, fillers, Pigments, accelerators, stabilizers and dispersants. On such modified binders are based on the adhesives and sealants.

Binders based on oleochemical reaction products are described in WO 95/11284. These include reaction products from

• A) at least one fat with an average of 1 to 6 at least one of the -COOH or acid anhydride groups in the fat residue (component A) with
• B) at least one average multifunctional connection, which for Reaction with the functional groups of fatty substances is capable (Component B) in deficit and
• C) Implementation of the remaining -COOH and acid anhydride groups Intermediate product with sodium hydroxide solution.

The object of the invention was to make binders based on such fatty substances to provide that can be processed thermoplastically well, in particular have a relatively low viscosity and can also be melted several times.

The solution according to the invention can be found in the patent claims. It consists primarily of the basis for the reaction products of

• A) at least one fat with an average of 1 to 6 at least one of the -COOH or acid anhydride groups in the fat residue (component A) with
• B) at least one average multifunctional connection, which for Is able to react with the functional groups of fatty substances (component B), in deficit and
• C) Implementation of the remaining -COOH and acid anhydride groups Intermediate with monofunctional compounds (component C) use, the monofunctional compounds alcohols or amines are.

The reaction products have an average molecular weight Mn (osmotically determined number average) of at least 1,500, in particular of at least 5,000 and preferably at least for certain applications 8 000 g per mole. The binder is still pourable or when applied at least malleable. The application takes place between 0 and 250 ° C, in particular between 20 and 150 ° C.

The reaction products according to the invention can be used several times (at least three, preferably melted 5 times and cooled again after one hour without crosslinking them to an infusible thermoset. they rather, remain thermoplastic; H. remeltable.

"Fat substances" (component A) include, above all, adducts of dienophiles Substances on fatty acids, fatty alcohols and their derivatives with at least one C-C double bond and at least 8 C atoms to understand if they  contain at least one -OOH or acid anhydride group in the fat residue. At least one substance from the following group of is used as component A) Fat substances used: saturated or unsaturated, unbranched or branched Fatty acids, fatty alcohols with at least 8 carbon atoms and their esters with one C-C double bond after addition of a dienophile, the Fat substances a molecular weight of <200, in particular of <300 and preferably of <800 g per mole. The fat is in the Usually not a single substance, but rather a mixture. This applies in particular to functionality. At least 1% of the fat Molecules usually have at least 3 functional groups of the same or of various types, preferably at least 3%. It is known to the person skilled in the art how far he can lead the implementation, in order to only branch the To get molecules or at least so easy a crosslinking that the Reaction products are still deformable. Fatty substances are preferred with a molecular weight (number average) <300 or oligomerized fatty substances with one Molar mass <800 g used per mole. Generally the molecular weight is < 200.

“Fatty acids” are understood to mean acids which contain one or more carboxyl Groups (-COOH) included. The carboxyl groups can be saturated, unsaturated, unbranched or branched alkyl radicals with more than 8, in particular more than 12 carbon atoms. You can next to the -C-C groups described above further groups such as ether, ester, halogen, Contain amide, amino, urethane and urea groups. To be favoured however, carboxylic acids such as native fatty acids or fatty acid mixtures.

In a preferred embodiment of the invention, esters or Partial esters of the above fatty acids with mono- or polyhydric alcohols used. "Alcohols" include hydroxyl derivatives of aliphatic and alicyclic saturated, unsaturated, unbranched or branched To understand hydrocarbons. In addition to monohydric alcohols also the low molecular weight known per se from polyurethane chemistry Chain extenders or crosslinkers with hydroxyl groups. Concrete Examples from the low molecular weight range are methanol, ethanol, propanol, Butanol, pentanol, decanol, octadecanol, 2-ethylhexanol, 2-octanol, Ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, 2,3-butylene glycol, hexamethylene diol, octamethylene diol, neopentyl glycol, 1,4-bishydroxymethylcyclohexane, Guerbet alcohol, 2-methyl-1,3-propanediol, Hexanetriol- (1,2,6), glycerol, trimethylolpropane, trimethylolethane, pentaerythritol, Sorbitol, formitol, methylglycoside, butylene glycol, the dimer reduced to alcohols and trimer fatty acids. Monophenyl glycol or rosin resins Derived alcohols such as abietyl alcohol can also be used for esterification be used.

Instead of the alcohols, OH-containing tertiary amines, polyglycerol or partially hydrolyzed polyvinyl esters can be used.

However, fats and oils (triglycerides) are expedient after addition of maleic anhydride or acrylic acid or methacrylic acid.

Amides of the abovementioned fatty acids can also be used as fatty acid derivatives be used. These can be implemented with primary and secondary Amines or polyamines can be obtained, e.g. B. with monoethanolamine, Diethanolamine, ethylenediamine, hexamethylenediamine, ammonia etc.

“Fatty alcohols” are understood to mean compounds that have one or more Contain hydroxyl groups. The hydroxyl groups can be saturated, unsaturated, unbranched or branched alkyl radicals with more than 8, in particular more than 12 carbon atoms. You can next to the -C-C groups contain further groups, e.g. B. ether, ester, halogen, amide, Amino, urea and urethane groups.

Symmetrical and asymmetrical ethers can be used as derivatives of the fatty alcohols and esters with mono- and polycarboxylic acids are used. Under Monocarboxylic acids are ant, vinegar, propion, butter, valerian, Capron, Önanth, Capryl, Pelargon, Caprin, Undecan, Laurin, Tridecan, Myristin, pentadecane, palmitin, margarine, stearin, nonadecane, arachine, Behenic, lignoceric, cerotinic and melissic acids. Polycarboxylic acids are e.g. B. Oxalic acid, adipic acid, maleic acid, tartaric acid and citric acid. At the same time can also be used as the carboxylic acid, the fatty acids described above and then give esters such as. B. oleic acid oleyl ester.

The fatty alcohols can also be etherified, in particular with the same or other fatty alcohols, but also with other polyhydric alcohols, e.g. B. Alkyl polyglycosides, dioleyl ethers, dimer diol ethers, diepoxydistearyl ethers, oleyl Butyl ether.

Mixtures of the above fatty substances can of course also be added.

In the case of the dienophilic substances with the C-C double bonds of the fat residues react, it is essentially maleic anhydride, Itaconic anhydride, acrylic acid and methacrylic acid or, more generally, "alkene or Alkyne components with electron acceptor substituents ". Among them are To understand compounds that are in the vicinity of the C-C double bond or triple bond at least one substituent with electron-withdrawing Have property that can in turn react with alcohols, such as. Legs Carboxyl, an anhydride or an aldehyde group. Such connections are e.g. B. in addition to the above: maleic acid, fumaric acid, citraconic acid, Itaconic acid, arconitic acid, acetylenedicarboxylic acid and 3,4,5,6-tetra hydrophthalic acid, acetylenedicarboxylic acid and 3,4,5,6-tetra hydrophthalic anhydride, crotonic acid, cinnamic acid and 2,4-pentadienoic acid or the aldehydes derived from these compounds.

Unsaturated fats and oils can be mixed with acid anhydrides, in particular Graft maleic anhydride at elevated temperature. Such implementations are in DE 43 05 397 z. B. described on rape oil or soybean oil.  

However, it is preferred to use dienophilic compounds such as e.g. B. maleic anhydride, methacrylic acid or acrylic acid in the sense of an ene addition or a Diels-Alder reaction. Such reactions are described for example in:
D. Stoye, W. Freitag (ed.), Lackharze, Carl Hanser Verlag, 1997, pp. 380-381 (maleinated and acrylated oils).

Under "average multifunctional compounds that react to the functional groups of the fatty substances are capable "(component B), above all to understand at least one of the following compounds: polyvalent Alcohols, amines, amino alcohols, mercaptans, aminomercaptans and Alcohol mercaptans. Component B preferably has only amino or alcoholic OH groups. In general, the molecular weight is Component B) less than 2,000 g per mole (number average). The functionality lies in the range from 1.5 to 4, preferably between 2 and 3. Those with the acid or Fatty substances provided with acid anhydride groups can be especially with difunctional compounds to polymeric molecules implement, e.g. B. with diamines, dialcohols (diols), amino alcohols and their Mercaptan variants. Here too, stoichiometry determines, depending on the Functionality of the fatty substances and component B) the detection and Falling below the gel point.

The decisive factor is the equivalence ratio of the functional groups of the Component A) and component B). It should be 0.1 to 0.7. A The stoichiometric ratio leads to thermosetting sooner or later Products.

More or less branched macromolecules or Polymers, including oligomers. It's about known reactions to build up polymers.

It is essential that the polyreaction to form reaction products with a average molecular weight MG of at least 1,500, in particular at least 5,000 g per mole (determined according to GPC).

The reaction can be accelerated so much by adding catalysts that it still runs within acceptable times at room temperature. So it is z. B. possible, the reaction of carboxylic acid anhydride groups with Alcohol groups by heteroaromatic amines, the further heteroatoms in the Ring included, accelerate strongly.

The monofunctional compounds (component C) are Hydrocarbon compounds with 2 to 18 carbon atoms and one of the following Groups: alcoholic OH group, amino group and mercaptan group. Also the use of aromatic alcohols and amines is possible. You will be in such an amount that no anhydride or carboxylic acid groups more available.

The binders according to the invention are already suitable as such for gluing and Sealing, especially for gluing. Depending on the specific purpose However, the binder for the production of adhesives or Sealants expediently added additives, e.g. B. waxes, Fillers, pigments, dispersants, stabilizers, viscosity regulators, Preservatives, solvents and resins. They are known, as are theirs Admixture.

The binders according to the invention are mainly in the form of a glue stick or a hot melt adhesive used for gluing.

However, the binders according to the invention are also suitable for the production of Dispersion adhesives and solvent-based adhesives.

The binders according to the invention are particularly suitable for bonding and Density of substrates with different elastic behavior or different coefficients of thermal expansion, which is usually at different substrates is the case. Possible substrates are: wood, Cardboard, paper, wall coverings such as wallpaper, cork, leather, rubber, felt, textiles, Plastics - especially PVC, be it in the form of foils or textiles Flat structures -, mineral substrates such as glass, quartz, slag, rock and ceramics and metals.

The invention is illustrated by the following examples:
The examples were carried out according to the following general work instructions. The specific data can be found in the table.

A) Preparation of the binder

The adducts (component A) are obtained by using the indicated Amount of oil with the specified amount of maleic anhydride (MSA) Allows to react 200 to 240 ° C under nitrogen.

The specified amount of the polyunsaturated was then added to the adduct Added compound at 80 ° C. The mixture was stirred for 1 hour Kept at 150 ° C.

Then the indicated amounts of the monofunctional compound added and stirring continued at 150 ° C. for about 1.5 hours. The MSA adduct obtained was characterized by the saponification number. All samples were able to three times 150 ° C melted and cooled to room temperature without the viscosity changed significantly.

B) Manufacture of glue sticks

The MSA adducts thus obtained served as binders for the production of glue sticks. Their recipe follows from the following compilation (each in parts by weight):

Example I

Binder I 73.4 Calcium stearate 8.9 Cutina LM 8.9 Loxiol G60 8.8

Example II

Binder II 78.3 Calcium stearate 8.5 Cutina LM 8.5 Loxiol G60 0.6

Example III

Binder III 94.5 Rilanit SP Micro 5.5

• - Explanation of the substances:
  Cutina LM is a trade name for a mixture of fatty alcohols, waxes and oils.
  Loxiol-G-50 is a trade name for di-cetyl stearyl phthalate
  Rilanit SP micro is a trade name for Glycenn tris (12-hydroxystearate)
  Emerest 400 is a trade name for polyethylene glycol 400 monostearate.

The recipe substances were mixed in the melt at approx. 150 ° C and then in cast a mold.

C) Adhesive properties

3 days after the glue sticks were removed from the mold, Properties checked.

Abrasion was assessed subjectively by manual application on copy paper.

Liability was determined as follows:
Manual application on a strip of copy paper with a width of 40 mm and a length of 100 mm. Glue a second strip of the same dimensions by rolling on with a 1 kg roller. Separate the strips glued together using a tractor from Erichsen with a constant feed of 100 mm / min. Visual assessment of the paper tear.

Claims (8)

1. Binder with a molecular weight of at least 1500 g / mol based on a reaction product of

• A) at least one fatty substance with an average of 1 to 6 at least one of the -COOH or acid anhydride groups in the fat residue (component A)
• B) at least one average multifunctional compound capable of reacting with the functional groups of the fatty substances (component B), in deficit and
• C) Reaction of the remaining -COOH and acid anhydride groups of this intermediate with monofunctional compounds (component C), characterized in that the monofunctional compounds are alcohols or amines.

2. Binder according to claim 1, characterized in that as Component A) at least one substance from the following group of Fats are used: saturated or unsaturated, unbranched or branched fatty acids, fatty alcohols with at least 8 carbon atoms and their Esters with a C-C double bond after addition of a dienophilic substance, the fatty substances having a molecular weight of <200, in particular <300 and preferably of <800 g per mole. 3. Binder according to claim 2, characterized by fatty substances in which the C-C double bonds with a dienophilic substance such as. B. Maleic acid anhydride, itaconic anhydride, methacrylic acid and acrylic acid implemented were. 4. Binder according to claim 1, characterized by the molecular weight of the Component B) of less than 2000 g per mole and in that the Component B) contains only amino groups and alcoholic OH groups. 5. Binder according to at least one of claims 1 to 4, characterized by a conversion ratio of components A) and B) of 0.1 to 0.7, based on the stoichiometric amounts. 6. Binder according to at least one of claims 1 to 5, characterized characterized in that component C) contains 2 to 18 carbon atoms. 7. Use of the binder according to at least one of claims 1 to 6 for gluing and sealing, especially for gluing in the form of a Glue stick or hot melt adhesive. 8. Use according to claim 7, characterized by the gluing and sealing of wood, cardboard, paper, wall coverings such as wallpaper, cork, leather, rubber, Felt, textiles, plastics - especially PVC, be it in the form of foils or textile fabrics, - mineral substrates such as glass, quartz, Slags, rocks and ceramics as well as metals.