DE2459419C2 - Process for the production of laminates - Google Patents

Description

the foils combined by pressing together and exposed.

2. The method according to claim 1, characterized in that the binders in addition to the components a and b still 1 to 10 percent by weight (based on a and b) of (meth) acrylic acid esters of aliphatisehen and / or C2 to C ^ alcohols containing cycloaliphatic amino groups and, based on the amino groups, 0.5 to 2 times equivalent amounts of a «- / 0-unsaturated one containing free carboxyl groups Contain carboxylic acid.

3. The method according to claim 1 and 2, characterized in that the binders in addition to the Components a and b up to about 50 percent by weight (based on a and b) of a reaction product from a polyester or polyether containing OH groups and having a molecular weight between 200 and 3000 and one «- ^ - unsaturated carboxylic acid, all OH groups should be esterified.

Photopolymerizable polyurethane molding compounds, which are also used as coatings and adhesives can, are known. They consist of a photopolymerizable prepolymer which contains both free isocyanate groups as well as unsaturated addition polymerizable double bonds. These compositions are so produced that both reactive isocyanate groups as a precondensate in different reaction stages polymerizable double bonds can also be introduced. Besides that this procedure is cumbersome it usually leads to molding compounds that are relatively highly viscous and therefore difficult to process. she must either be dissolved in solvents or larger amounts of polymerizable monomers. ||

The object of the present invention was to find those photopolymerizable mixtures which can be used to * -

Suitable for binding foils together and do not contain any solvents. Another object of the invention consisted in specifying a method of bonding foils to one another that did not require long heated drying routes to remove the solvent is sufficient.

The method according to the invention for producing laminates from polyolefin films or polyolefin films with polyvinyl chloride, polyester, polyamide, cellulose film and / or metal foils by means of reactive isocyanate groups containing binders, is characterized in that between the to be connected Films, at least one of which should be permeable to short-wave light, apply a mixture

a) 30-80 percent by weight of free isocyanate groups containing reaction product from a di- or Triisocyanate and a polyester or polyether containing OH groups of one molecular weight between 200 and 5000 and

b) 70-20 percent by weight of monomeric acrylic acid ester and / or methacrylic acid ester of aliphatic and / or cycloaliphatic alcohols with 2 to 18 carbon atoms in such a molar ratio that the average number of carbon atoms is between 3 and 6 and
c) an additional 0.2-0.5 percent by weight, based on components a) and b), the photopolymerization

initiating connections and
55

the foils combined by pressing together and exposed.

The reaction products containing free isocyanate groups are prepared by those containing OH groups Compounds such as polyester or polyether with an OH number between 20 and 200 are possible. The polyester can in a known manner by esterification of polyhydric alcohols such as ethylene glycol, di-, tri- or Tetraethylene glycol, propylene glycol, di- and tripropylene glycol, 1,6-hexanediol, 1,3-butanediol and 1,4-butanediol, Neopentyl glycol, if necessary also with the use of polyfunctional alcohols such as glycerine, trimethylolpropane, Pentaerythritol with carboxylic acids, especially saturated dicarboxylic acids, e.g. B. adipic acid, Sebacic acid, cyclohexanedicarboxylic acid, dimerized fatty acids, phthalic acid, isophthalic acid, terephthalic acid. Naphthalenedicarboxylic acid and the like. You can also use lower, multi-valued PolycaproUctone modified with alcohols such as ethylene glycol or propylene glycol or butylene glycol Molecular weight between 300 and 2000 as an OH component come into question. The components for the polyester should be selected in such a way that products with the lowest possible viscosity are formed at room temperature. This can can be easily achieved if mixtures of alcohols and carboxylic acids are used. Besides, the

Viscosity can be controlled to a certain extent by setting the OH number. Are polyglycols as containing OH groups Components used, like the polyesters, they should be of relatively low viscosity. It Polyäthylenengiykol with a molecular weight up to about 800 or mixed ones come into question here Polyethylene propylene glycols, which can have a molecular weight of up to 5000.

The quantitative ratio to the OH group-containing polyester or polyether and di- or triisocyanate should be as follows be chosen so that there are 2.05 to 2.8 or 3.05 to 33 isocyanate groups per OH group. As isocyanates are for example suitable the isomeric tolylene diisocyanate, diphenylmethane diisocyanate, trimethylhexanemethylene diisocyanate, Isophorone diisocyanate and optionally triphenylmethane triisocyanate or the adduct of tolylene diisocyanate to trimethylolpropane (Mo ratio 3: 1). It is also possible to others Glycols such as di-, tri- or tetraethylene glycols or the corresponding propylene glycols as well To let butylene glycols react with smaller amounts of diisocyanate, so that condensates with both terminal isocyanate groups as well as internal ether groups and urethane groups.

The reaction between the components containing OH groups is carried out in a manner known ^{per se between about 60 and 120 °} C. for 1 to 5 hours, if possible with the exclusion of atmospheric moisture.

The component to be used further for the binder to be used according to the invention consists of monomeric acrylic ester and / or methacrylic ester of aliphatic and / or cycloaliphatic alcohols with 2 to 18 carbon atoms. Particularly suitable alcohols are propanol, butanol, i-butanol and mixtures of the isomeric hexanols in question.

It has proven to be useful. Use mixtures of acrylic esters and methacrylic esters, namely preferably mixtures of the butanol esters. By varying the amount of acrylic acid and methacrylic acid buty ! ester, the flexibility of the binder film, among other things, can be varied.

Substances known for this purpose are used as the compound which triggers the photopolymerization Question how benzoin or the benzoin ethers, e.g. B. Benzoin methyl, benzoin ethyl and benzoin propyl ether. Suitable but are also chlorinated aliphatic and aromatic hydrocarbons and diketones, such as benzil or diacetyl or phenones such as acetophenone or benzophenone and certain organic sulfides such as Diphenyl monosulfide, diphenyl disulfide and tetramethylthiuram monosulfide or also S-BenzoyI-N, N-D.'methyldithiocarbamate.

According to a preferred embodiment, the binders to be used according to the invention contain in addition to the reactive components a and b, 1 to 10 percent by weight of (meth) acrylic acid esters from aliphatic and / or cycloaliphatic amino groups containing C2 to C ^ alcohols and, based on the amino groups, 0.5 to 2 times equivalent amounts of a free carboxyl group «- / ^ - unsaturated carboxylic acid. The amino group in the alcohols should not be quaternary or with a strong one Acid neutralized. The amino nitrogen is preferably tertiary because it contains secondary or primary nitrogen compounds only very limited storable binders can be obtained. It has proven to be beneficial To use amino alcohols with 4 to 12 carbon atoms, such as dimethylaminoethanol, dibutylaminoethanol, Dimethylaminopropanol, dimethylaminobutanol, diethylaminoethanol, dicyclohexylaminoethanol and Cyclohexylmethylaminoethanol. As «- ^ - unsaturated carboxylic acids come into question, which are with Allow acrylic esters to copolymerize. Acrylic acid or methacrylic acid is particularly suitable. In principle are Itaconic acid, crotonic acid or maleic acid / fumaric acid can also be used as comonomers, in particular when they are used in a mixture with predominant amounts of acrylic acid or methacrylic acid.

According to a further preferred embodiment, the binders to be used according to the invention can, in addition to components a and b, also contain up to about 50 percent by weight (based on a and b) of an esterification product made from a polyester or polyether containing OH groups and having a molecular weight between 200 and 3000 and contain a <x-ß unsaturated mono- or dicarboxylic acid. Suitable polyesters or polyethers containing OH groups and unsaturated carboxylic acids are the same as those already described in more detail at the outset. All OH groups should be fully esterified.

In some cases it has also proven to be useful to add so-called unsaturated binders to the binders Add polyester. These polyesters are often commercially available in polymerizable monomers such as Styrene is dissolved and can be used in this form. Such unsaturated polyesters contain besides saturated dicarboxylic acids such as adipic acid and phthalic acid are the residues of maleic acid and fumaric acid, respectively. Of course, other polymerizable monomers can also be used instead of styrene, for example vinyl acetate, vinylidene chloride, vinylpyrrolidone, acrylonitrile and possibly also dibutyl maleic ester, Dioctyl maleic acid and the like. Finally, there are other possible additions Ethylenically unsaturated compounds such as acrylamide, diacetone acrylamide, divinylbenzene and the like in Question.

After the binders according to the invention have been applied, expediently in thin layers, which should be between about 1.5 to 30, in particular 3-10 g / m ² , the films are pressed onto one another under roller pressure and irradiated with high-energy light. High or low pressure mercury vapor lamps are possible here, the spectrum of which is in a range from around 1700 to 6000 Å. Of course, it is also possible to use other high-energy rays such as gamma rays or electron beams. The irradiation triggers the polymerization of the double bonds, and a high level of strength is achieved after just 20 to 30 seconds, which is always sufficient to prevent delamination phenomena. After 1 to 4 days, the connection then reaches its final strength, the isocyanate groups evidently reacting with a thin film of moisture that is always present or with other reactive groups present on the surface.

When making the connection, make sure that one of the two foils is good for the radiation is permeable that the polymerization can be initiated. As a rule, one is therefore from the side of the Irradiate the polyolefin film. The method according to the invention can be used to connect polyvinyl

chloride-. Polyester, polyamide, cell glass or metal foils, for example made of aluminum. Copper or the like, with these films having the usual layer thickness between about 10 to 150 μ, in particular 15 to 100 μ, have ropes.

The method according to the invention enables firm connections to be made between the foils. When the usual precautionary measures are taken, no amines are released and, in particular, no nuisance caused by organic solvents

Manufacture of the raw materials

A) With the exclusion of atmospheric moisture, 200 g of a polyester made from diethylene glycol and isophthalic acid were added and adipic acid (molar ratio of acids 1: 1), which had an OH number of 58, 50.6 g of isophorone diisocyanate and 60 mg of dibutyl-Sn-dilaurate were added and the mixture was stirred at 65 ° C. for 3 hours

B) To 200 g of the polyester characterized as above were added with exclusion of atmospheric moisture 253 g of isophorone diisocyanate and 24.0 g of trimethylhexamethylene diisocyanate and 60 mg of dibutyl-Sn-Dilau rat added and stirred for 3 1/2 hours at 6O ⁰ C with exclusion of atmospheric moisture

C) 55.5 g of maleic anhydride were added to 500 g of a polyester as characterized under A) and stirred for 3 hours at 125 ° C. under a nitrogen atmosphere

Solvent-free binders were prepared from those given in the examples below Components

example

57.55 g of isocyanate condensate B

19.15 g butyl methacrylate

19.15 g of butyl acrylate, 1.28 g of acrylic acid

2.87 g of methacrylic acid ester of dimethylaminoethanol, 2.00 g of benzoin methyl ether

example

43.16 g of isocyanate condensate B, 8.65 g of butyl methacrylate 22.28 g of butyl acrylate 7.63 grams of styrene 14.15 g of commercially available photopolymerizable polyester

(Containing maleic acid / fumaric acid) 1.28 g acrylic acid 2.87 g of methacrylic acid ester of dimethylaminoethanol 2.00 g of benzoin methyl ether

example

51.90 g of isocyanate condensate B 10.40 g butyl methacrylate, 25.23 g butyl acrylate, 2.94 % styrene

5.45 g of commercially available photopolymerizable polyester (containing maleic acid / fumaric acid) 1.28 g acrylic acid 2.87 g of methacrylic acid ester of dimethylaminoethanol 2.00 g of benzoin ethyl ether

B e 1 s ρ i e 1

46.60 g of isocyanate condensate B, 15.50 g of butyl methacrylate 15.50 g of butyl acrylate, 1.08 g of acrylic acid 232 g of methacrylic acid ester of dimethylaminoacrylate 19.00 g unsaturated polyester C 2.00 g of benzoin methyl ether

Example 5

46.60 g of isocyanate adduct A

15.50 g of butyl methacrylate

15.50 g of butyl acrylate

1.08 g acrylic acid

2.32 g of methacrylic ester of dimethylaminoethanol

19.00 g unsaturated polyester C

2.00 g of benzoin ethyl ether

With the binders according to the preceding examples, polyethylene films of 50 μ thickness were coated using a 5 μ doctor blade, so that the application was about 4 g / m ² . The second film was then applied under slight pressure and exposed through the polyethylene film to an Hg vapor lamp (2380-5790 A, 180 watt) for 20 seconds, the distance being 5 cm. A fan was used for cooling.

In the table below, the binder used is indicated in the first column, and in the following column the second film and the 15 mm wide strips at a take-off speed of 100 mm / min Values in ponds / cm measured for 5 minutes and then the peel forces measured after storage for 3 days.

Tabel

binder

Applied film

Pull-off force
in pond

Withdrawal force in pond
after 3 days

example 1

Example 2 Example 3

Example 4 Example 5

Polyethylene terephthalate 19 μ aluminum 15 μ Polyethylene terephthalate 19 μ Polyethylene terephthalate 19 μ Polyamide 50 μ

Polyethylene terephthalate 19 μ, polyamide 50 μ

Cell glass coated with polyvinylidene chloride 24 μ

40 400 100 700 100 450 100 400 170 500 60 400 70 550 80 350

Claims (1)

Patent claims: 1. Process for the production of laminates from polyolefin films with one another or with polyolefin films Polyvinyl chloride, polyester, polyamide, cell glass and / or metal foils by means of reactive socyanate groups containing binders, characterized in that between the Films, at least one of which should be permeable to short-wave light, apply a mixture a) 30-80 percent by weight of free isocyanate groups containing reaction product from a di- or Triisocyanate and a polyester or polyether containing OH groups of a molecular weight ι ο between 200 and 5000 and b) 70-20% by weight of monomeric acrylic acid ester and / or methacrylic acid ester of aliphatic and / or cycloaliphatic alcohols with 2 to 18 carbon atoms in such a molar ratio, that the average number of carbon atoms is between 3 and 6 and c) an additional 0.2 to 5 percent by weight, based on components a) and b), the photopolymerization is triggering links and