DE2165841C3 - Means for repelling rodents, insects and other pests - Google Patents

Description

30th

It is a vitally important task to collect food, grain, plants, underground pipes, such as underground cables and other objects to protect against rodents, insects and other pests. Rodents continually cause great damage to food and grain by eating and / or destroying them and great losses. Furthermore, they often gnaw the insulation of underground electrical lines and Telephone lines and cause malfunctions. Insects cause losses of Food by rendering it inedible or unusable.

A number of substances are known and used as a means of repelling rodents, insects and other pests. For example, the Ν, Ν-Dimethylsulfenyldithiocarbamate turn out to be as very suitable. Reference is made to US patents 26 21 143 and 28 62 850. As a repellent Agents are also known according to US Patents 28 22 295 and 28 22 296 also dodecylamine acetate and dodecyl alcohol. In this sense, the repellent agents also include those in the US patent 27 17 851 named polycyclic halogenated compounds.

For practically all substances that can be used as repellants, the use of the prepares protection point or in connection with the goods and objects to be protected difficulties. Usually one uses carriers or additives to make the use of the repellent facilitate. Various plastics have been proposed as a carrier for the repellent. For example repellants have been added to plastics, which are used to insulate electrical cables used, or they have been added to plastic foils or films that are used for packaging Foods used. But even here you run into difficulties. In many cases, the It is difficult to incorporate repellants into the plastic or they are even incompatible with it it also often happens that the repellent is not in sufficient concentration in the plastic can be introduced or that the preparation made from it and the plastic is not durable These difficulties are also evident when mixing and / or tableting or pelletizing the Mixture. In such cases the repellent can only work with the plastic with great difficulty be mixed or a mixture of the two can only be tabletted or compressed in an extruder with great difficulty. pelletized, d. H. be brought into the form in which plastics are usually used for later uses sold. It also sometimes happens that the plastic and the repellent appear to be one another let mix and that the mixture can be tabletted or pelletized that of the two Components of existing preparation but not durable. Show the instability of the preparation! himself because the repellent (hereinafter also called the active substance) "bleeds out" of the plastic or retires. It can also be seen in the smell. These difficulties arise especially noticeable when concentrating with the repellants or active substances Wants to manufacture preparations that are then diluted by the processor for final use will.

According to the invention, the difficulties described are eliminated by a new means for repelling rodents, insects and other pests with a larger proportion of a plastic as a carrier and a smaller proportion of a compound imparting the repellent effect, preferably an alkylsulfenyl carbamate, which is characterized in that the carrier is a copolymer of ethylene and a 1-olefin having 4 to 6 carbon atoms in the molecule, the copolymer containing 4 to 10% by weight of the 1-olefin comonomer and having a density of 0.919 to 0.930 g / cm ³ , the mean molecular weight by weight of the copolymer is in a ratio of 6: 1 to 20: 1 to its minimum number molecular weight and the copolymer has a melt index of 0.1 to 5.0.

The agent according to the invention is characterized by an unusually high capacity for the repellent compounds, making it possible to prepare preparations with high concentrations of these Establish connections without bleeding of the repellent connections.

From US-PS 32 48 288 pesticides are known which consist of a solution of a polymeric material and a pest control agent in a hydrocarbon solvent. This patent also mentions copolymers of ethylene with 1-butene and 1-hexene among numerous polymeric materials, although there is no information about the proportion of the individual monomers. In addition, the known copolymers should have a density of 0.93 to 1.00 g / cm ³ , preferably 0.94 to 0.98 g / cm ³ and consequently be of a higher density than the copolymers used in this invention. Furthermore, in addition to the polymeric material and the active ingredient, the known pesticides always contain a hydrocarbon solvent, which is not provided here.

The copolymers used as carriers according to the invention are copolymers of ethylene and 1-olefins with 4 to 6 carbon atoms in the molecule, which have a density of 0.9! 9 to 0.930, preferably a density of at least 0.920. Copolymers with a content of 5 to 9 are preferably used Wt% 1-olefins. Among the olefin comonomers, butene-1 is of particular interest, so that copolymers of ethylene and butene-1 are preferred in the invention.

The copolymers used in the invention are free from surface tackiness and have against Cracks caused by stress corrosion have a durability of more than 100 hours (Failure rate 50%). Even more preferably, copolymers having 14 to 21 ethyl branches are used for 1000 carbon atoms. These copolymers preferably contain 0.5 to 0.7 vinyl groups per 1,000 Carbon atoms.

A particular characteristic of the copolymers used for the purposes of this invention of low density polyethylene is that it is unlike long chain branches (butyl residues or longer residues) ethylene branches and except

which contain a considerable number of unsaturated vinyl groups.

The copolymers used according to the invention differ from the previously known copolymers of ethylene and 1-olefins in their density and their molecular weight distribution, d. H. by the ratio of the average weight molecular weight to mean number molecular weight. Furthermore, their resistance to stress corrosion is significantly greater than that of the previously known copolymers from ethylene and 1-olefins.

Another advantageous feature of the Invention used copolymers is that they do not bleed and no surface tack and none Have a "cheesy" handle.

The following table compares the properties of copolymers of the type used in the present invention, referred to as Copolymers A and B, with the properties of commercial low density polyethylene and the properties of a copolymer of the type described in US Pat. Patent 31 02 876 described type, referred to as "control polymer"

table

Copolymer
A.

Copolymer
B.

Commercially available polyethylene with
low density

Control polymer

Density (g / cm ³ ) melt index

Average Weight Molecular Weight J.t? -) Average Number Molecular Weight (Mn) Mw ; Mn

Elongation at break (%) tensile strength (kg / cm ² ) flexural modulus (kg / cm ² ) hardness

Long chain branches (butyl and longer) for 1000 carbon atoms Ethyl groups on 1000 carbon atoms Internal trans double bonds for 1000 carbon atoms

Unsaturated vinyl groups per 1000 carbon atoms. Branched unsaturated vinyl groups for 1000 carbon atoms

Resistance to stress corrosion in hours (Failure rate 50%)

0.9255 0.9237 0.927 0.93 0.13 0.10 0.15 2.0 213,000 165,000 259,000 17 700 27 600 7900 12.0 6.0 33.0 360 - 565 73 127 - 148 139 4850 4220 5270 55 58 56 - - 22nd - 16 16 0.1 0.1 0.1 - 0.6 0.6 0.1 0.2 0.1 0.2 - 1000 1000 65 20th no "cheesy" Handle, no "Cheesier" bleed out Handle, star kes off blossoms

While after an aging carried out in an oven at 60 ° C in the case of the invention copolymers used shows neither bleeding nor surface tackiness, a strong one shows up Bleeding on the control polymer.

The density of the copolymers listed in the table is determined with a "gradient column" of samples, which are pressed at a temperature slightly above the melting point and then cooled at a rate of 8 ° C per minute (ASTM-D 1505-63T). The melt index is determined according to ASTM-D 1238-65T. The molecular velocity distribution is determined by the ratio of the weight average referred to the number average molecular weight. A high value for this ratio indicates a broad molecular weight distribution. Both the weight average and the number average of the molecule large weight, as described by J. C. Moore in »]. Polymer Science «. Part A; Vol. 2 (1964) on pages 835-843, determined by gel permeation chromatography (GPG). The GPG method is calibrated for the number average molecular weight by membrane osmometry and for weight average molecular weight by light scattering. The tear resistance properties are determined according to ASTM D. 638-6IT on samples that were slightly above the

Melting point lying temperature and then pressed at a rate of 14 (± 2.7) ° C be cooled. The throughput speed is 51 cm per minute. The flexural modulus is determined ASTM-D 790-63, the hardness according to ASTM-D 1706-61 and the cracking caused by stress corrosion according to ASTM-D 1693-66. The ethyl branch is indicated by an infrared absorption band at 13 microns and the long chain branches are indicated by absorption at 11.2 microns after through Bromination has eliminated the interference of the unsaturated bond at 11.25 microns on these Branches to terminal methyl groups are determined using a differential method at 7.25 Measured microns. The unsaturation is determined by measuring microns, using the The film is subsequently brominated to determine the amount of spectral interference.

Copolymers A and B can be prepared as follows:

(A) A catalyst is first prepared in such a way that microspheroid silica is used with it Chromium oxide impregnated and the product obtained activated at 760 ° C for 5 hours. The catalyst obtained contains 1.9% by weight of chromium trioxide. One then brings a mixture of ethylene with an 11% strength by weight butene-1 content existing starting material with the simultaneous addition of 0.02 mol of hydrogen to 1 mol of des Ethylene together with the catalyst in isobutane as a diluent, heats the mixture under a pressure of 23 atm. to 89 "C and holds it for 90 minutes at this temperature. The reaction results 2150 g of the copolymer containing about 5% by weight of butene-1 per 1 g of the catalyst.

(B) A catalyst is first prepared by impregnating a microspheroidal mixture of 88% by weight of silica and 12% by weight of alumina with chromium oxide and activating the product obtained at 760 ° C. for 5 hours. The catalyst obtained contains 2% by weight of chromium trioxide. A starting material consisting of ethylene with a 19% by weight content of 1-butene is then brought together with the catalyst in isobutane as the diluent, and the mixture is heated under a pressure of 3? Atm. to 93 ⁰ C and holds it for 90 minutes at this temperature. The reaction yields 1900 g of the copolymer containing about 5% by weight of butene-1 per 1 g of the catalyst.

According to this, for the preparation of copolymers which can be used for the invention, catalysts can be used which consist of chromium oxide on a porous support and contain about 1.5 to 2.5% by weight of chromium trioxide, which is stored for about 4 to 15 hours at a temperature of 677 to 899 ⁰ C has been activated. The starting material can be a mixture of ethylene and a 1-olefin having 4 to 6 carbon atoms, which contains the two components in a ratio of 8: 1 to 15: 1. It can be brought together with the catalyst at a temperature of 71 to 107 ° C., expediently at a temperature of 82 to 99 ° C. and under a pressure of 17 to 48 atm., Expediently under a pressure of 20 to 41 atm. The catalyst can be used in the usual amounts, but preferably in an amount of from about 0.5 to about 1% by weight of the starting material. Bring the two substances preferably in a suitable hydrocarbon as a diluent, for example in isobutane, pentanes or hexanes .-% alumina existing mikrospäroidisches mixture impregnated with chromium trioxide and the resulting product is activated for 5 hours at 510 ⁰ C. The catalyst contains 2.6% by weight of chromium. The catalyst is then brought together in cyclohexane as a solvent with a starting material consisting of ethylene with a 13% by weight content of 1-butene, and the mixture is heated under a pressure of 17 atm. to 121 ° C and keep it at this temperature for Ϊ20 minutes. The reaction yields 418 g of the copolymer containing about 5.5% by weight for 1 g of the catalyst.

For the purposes of the invention, the copolymers are preferably used in the granular, porous form in which they are essentially obtained from the reaction vessel. In this form, ie before they are tabletted or pelletized, the copolymers normally have a bulk density of 0.29 to 0.38 g / cm ³ , as a rule a bulk density of 0.32 to 0.35 g / cm ³ . Normal sieve analyzes show that about 90 to 99% by weight of the granular, porous copolymers have a particle size of 10 to 60 mesh of the US standard sieve series. However, it is within the scope of the invention to first aggregate the copolymer in a known manner and then to mix it with the repellent.

Any suitable repellent compound can be used as the active substance for the preparation of the repellent preparations according to the invention. It is currently preferred to use alkylsulfenyl carbamates, such as Ν, Ν-dimethylsulfenyldithiocarbamate. According to US Pat. No. 2,390,713, these dithiocarbamates can be prepared by reacting an alkyl salt of an N-substituted dithiocarbamate with an aliphatic sulfenyl thiocyanate. According to a further process, which is described and claimed in US Pat. No. 2,792,394, the dithiocarbamates are prepared by reacting a lower alkylsulfenyl halide with salts of N-substituted dithiocarbamic acid in aqueous solution. It is presently preferred to operate according to this latter method. A dithiocarbamate which is particularly suitable for the purposes of the invention is N ₁ N-dimethyl-S-tert.-butyl-sulfenyldithiocarbamate. Good

N.N-dimethyl-S-methyl-sulfenyldithiocarbamate can also be used.

The amount of the repellent or active substance to be admixed with the copolymer can depend on on the effectiveness of the substance and the particular purpose for which the agent is used should fluctuate within wide limits. Usually one applies the active substance in a small one, however sufficient effective amount on the places or on the goods or objects that one is against Want to protect rodents, insects or other pests. If the preparations go directly to the to be brought to a protective location or to be applied to the goods or objects to be protected, the agent usually contains 0.05 to 2 or 3% by weight of active substance.

As the copolymers used for the invention absorb active substance in large amount capacity, they are particularly suitable for the production of concentrates of the active substance. Such Concentrates can contain any suitable amount of substance, for example at least about 5% by weight,

better at least about 10% by weight, preferably at least about 20% by weight or more. You can do this Then dilute the concentrates to the desired concentration. The concentrates are therefore mainly for Manufacturers with a wide range of products are important because they are different for the intended purpose Amounts of active substance to be used have to work.

The agents according to the invention consequently contain the active substance preferably in amounts between 0.05 and 20% by weight, concentrates with a high content of active substance being preferred. Like from the As shown in the following example, the copolymers used in the invention are excellent for suitable for the production of the substance concentrates according to the invention. It is surprising and contrary to all Expectation that these copolymers are suitable, the large amounts of active mentioned in the example To absorb substance.

Example and comparative experiments

A catalyst is produced by impregnating a microspheroidal mixture of 88% by weight of silica and 12% by weight of alumina with chromium oxide and then activating it at 760 ° C. for about 5 hours. The catalyst contains about 2% by weight of chromium trioxide. This catalyst is then brought with a mixture of ethylene and 1-butene, which contains 1-butene in an amount of 13% by weight, in the presence of isobutene as the diluent at a temperature of 84 ° C. under a pressure of about 36 atm. together. The reaction is carried out continuously in a loop reactor and the copolymeric product which forms in granulated form is continuously withdrawn from the reaction vessel. It contains about 8% by weight of butene-1. After its recovery from the isobutane, the copolymeric product has a density of 0.924 g / <_ rr! ³ and a melt index of 0.11.

It is made from the copolymer and N, N-dimethyl-S-tert.-butylsulfenyldithiocarbamate Prepare a series of blends in the following manner: Put the copolymer in a Henschel mixer, heat it in it to about 60 ° C, then the active substance sets and works it into the copolymer by adding the the two components mixed for about 2 to 4 minutes to form a homogeneous mass. Mixes are made with a content of 5, 10 and 20% by weight of active substance.

The mixtures are then tabletted or pelletized in a conventional manner at 149 to 177 ° C. in one Extruder and lets the tablets or pellets stand for 48 hours. None of the tablets or pellets shows exudation or bleeding of active substance after this time. The tablets or pellets have also a low and quite tolerable odor level. Other samples of the same mixes show after they have been kept in a closed container in a cool, dry place for a long time had that the mixtures have an unlimited shelf life.

Essentially in the same way as the above-described copolymer, in the absence of butene-1, an ethylene homopolymer with a density of 0.959 g / cm ³ and a melt index of 0.3 is prepared. This homopolymer is then prepared with N, N-dimethyl-S-tert-butylsulfenyldithiocarbamate in a Henschel mixer in the manner described above

ίο Mixtures that contain 5 or 10% by weight of the active Contain substance.

When trying to tablet or pelletize the two mixtures, taking into account the properties of the homopolymer accordingly, in the device at a temperature of 204-232 ° C must work, one finds: The 10 wt .-% of the dithiocarbamate containing as active substance Mixture cannot be tabletted or pelletized at this temperature because the active substance dissolves from the homopolymer and flows out of the device. Even when trying to finish the 5th Tabletting or pelletizing by weight% of the repellent substance-containing mixture is expelled the same reason for difficulties when in this case also active substance in small amount in and is retained on the pellets. In addition, a strong one develops during pelletization Smell of the dithiocarbamate, which indicates the leakage of this substance.

It also produces from a commercially available ethylene homopolymer in the form of pellets, which has a density of 0.917 g / cm ³ and a melt index of 7.1, and NN-dimethyl-S-tert-butylsulfenyldithiocarbamate as the active substance, two mixtures, the 5 or Contain 10% by weight of this substance. The two components are mixed dry in a mixing drum.

When trying to make the two mixtures at a temperature of 149 to 177 ° C in an extruder pelletize, it is found that the mixture containing 5% by weight of the active substance is likely to pelletize allows the active substance to appear on the surface of the pellets after 48 hours and that the pelletized preparation has a strong and unpleasant odor. The 10% by weight of the active substance The mixture containing it cannot, however, because of the lubricating effect of the dithiocarbamate can be pelletized. This lubricating effect of the dithiocarbamate causes the pelletizer to mix in a fluctuating amount, d. H. is fed irregularly.

For further experiments, mixtures of the type described are produced with another commercially available polyethylene which has a density of 0.913 g / cm ³ and a melt index of 200. For the reasons mentioned, these mixtures can also only be pelletized unsatisfactorily for the reasons mentioned.

These experiments show the superiority of those used as supports according to the invention Copolymers versus similar polymers.

709 617/195

Claims (4)

Patent claims: 1. Means for repelling rodents, insects and other pests with a larger proportion of a plastic as a carrier and a smaller proportion of a compound imparting the repellent effect, preferably an alkylsulfenyl carbamate, characterized in that the carrier is a copolymer of ethylene and a 1 -Oleefin having 4 to 6 carbon atoms in the molecule, the copolymer containing 4 to 10% by weight of the 1-olefin comonomer and having a density of 0.910 to 0.930 g / cm ³ , the mean molecular weight of the copolymer being its number molecular weight is in a ratio of 6: 1 to 20: 1 and the copolymer has a melt index of 0.1 to 5.0 2. Composition according to claim 1, characterized in that the carrier is a copolymer of ethylene and butene-1 is. 3. Means according to claim 1 or 2, characterized in that the repellent compound N.N-Dimethyl-S-tert-butylsulfenyldithiocarbamate is. 4. Composition according to claim 1, characterized in that it contains from 0.05 to 20 wt .-% of the repellent Connection contains.