DD210462A1 - SOLVENT MIXTURES FOR THE PREPARATION OF ADHESIVES - Google Patents

Abstract

The invention relates to solvent mixtures for the production of adhesives based on chlorine-containing thermoplastic polymers, which are preferably used for bonding semi-finished products or molded parts made of these materials. The aim is to reduce the technical-oeconomic production cost for the adhesives, a universal application possibility of chlorine-containing thermoplastic polymers as a solid component d. To ensure adhesives and to improve the quality of the adhesives. The object is to provide solvent mixtures which have a good solubility for chlorine-containing thermoplastic polymers. As a solution, it is proposed that the solvent tetrahydrofuran 5 to 40 wt .-%, preferably 10 to 30 wt .-%, of a straight-chain or branched aldehyde of chain length C4 to C8 or one of d. Aldehyde derivable acetal, enolacylates, diacylates o. Dichloraldehydes is added. These solvent mixtures have an excellent solubility for chlorine-containing thermoplastic polymers, so that it is easy to produce high-quality adhesives based on these compositions.

Description

ο '-> ο ο

VSB Chemiekombinat Schwerin, 26.7.1982

Bitterfeld 227δ

ν } title

Solvent mixtures for the production of adhesives

Field of application of the invention;

The invention relates to a solution for the production of adhesives based on ciliary thermoplastic polymers which are preferably used for bonding semi-finished products or molded parts made of these materials »

Characteristic of the known technical solutions

There are solvents or solvent mixtures known which are used for the preparation of Lö.sungsmittelhaltigen adhesives based on thermoplastic polymers.

As such solvents for chlorine-containing thermoplastic polymers are generally found: '

- chlorinated hydrocarbons, such as ξ · 3. Trichlorethylene, methylene chloride, tetrachlorethylene, chlorobenzene

aromatic hydrocarbons, e.g. Benzene, toluene

- ketones, as z.3. Cyclohexanone, methyl ethyl ketone, pr-opanone and

heterocyclic compounds, such as z.3, tetrahydrofuran, application,

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The choice of solvent or solvent mixtures essentially determines the physical properties of the adhesive.

In practice, for this reason, for the production of adhesives for joining highly stressed parts. Chlorine-containing thermoplastic polymers used predominantly as a solvent tetrahydrofuran (THP), since THP is known for chlorine-containing thermoplastic polymers as a very suitable solvent, ..-

In order to improve the processability of THF-containing adhesives based on chlorine-containing thermoplastic polymers, in particular to delay the curing of the adhesive, a certain amount of the THP is frequently replaced by a less volatile solvent, eg. Cyclohexanone, dimethylformamide, methyl ethyl ketone replaced. This is eg. From DE-OS 23Ö48O6 a method is known, according to which for the preparation of adhesives based on a compound consisting of 2 to 50 parts by weight of a chlorinated polyethylene (CPE) and 100 Ge ¹ W, parts of a Vinyichlorid polymer, as a solvent among others. THP is used ». ,

However, it was found that the CPE in the chlorine range of. 5 to 50 percent by weight in THP or, in mixtures consisting of THP and other solvents, is not always completely dissolved and so.The adhesive gel-like and less good spreadable.

According to DE-OS 2132479, the solvent used is THP for an adhesive consisting of polyvinyl chloride resin and plasticizer. This is used exclusively for bonding a highly plasticized vibration-elastic polyvinyl chloride. Although THP has already used one of the strongest solvents, long setting times of several hours have to be accepted.

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When bonding post-chlorinated PVC, the so-called CPVC, long setting times are also to be expected since the CPVC absorbs the THF only moderately quickly and releases it only slowly. When making the adhesive on the basis of CPVC and THP the same problems occur and the adhesive is difficult to process, (♦ 'adhesives and bonding process for plastics', VDI-Verlag Dusseldorf 1974, S, 80)

Furthermore, DE-A-1569966 describes solutions of suspension-chlorinated polyvinyl chloride (PVC) as adhesives. However, these have the disadvantage that they still have to be filtered before use because the chlorinated PVC is dissolved in THF or in a mixture of THF and cyclohexanone is not completely soluble. This filtration is associated with significant difficulties and resource loss.

For the elimination of these ITachteile is a PVC used in the manufacture of adhesives., Which was treated before or during the chlorination with chlorinated hydrocarbon, disadvantageous in this method, however, is the high by the additional treatment with chlorinated hydrocarbon technical-economic effort, which by the chlorinated hydrocarbon, the adhesive properties be adversely affected.

In this DE-OS was also referred to that PVC in THF shows a poor or only partial solubility, so that adhesives on this basis have a low solids content and are gel-like. Such adhesives are inherently difficult to process and do not have the bei.Klebstoffen desired gap-filling properties.

Furthermore, it is known from DD-PS 47553 that the suitability of the solvents used in the production of adhesives, such as e.g. THF. depends on the chlorine content of the chlorinated PVC Konkonnentε. As is the case with the conventional ones

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Chiоrierungsterfahren is not possible to produce a product with a constant chlorine content, this inevitably leads to product-related solubility differences of the material batches used, with adhesives on this basis have the disadvantages already pointed out *.

From the known state of the art shows that the use of TEE ¹ or mixtures of THP and other solvents in the production of adhesives based on thermoplastic chlorine-containing polymers is limited to very specific polymer charges or a complex pretreatment of the polymers or, aftertreatment of requires prepared adhesives. Besides, these adhesives only. ^: rarely the required. Properties such as good processability, high strength and good gap filling.

Object of the invention

The aim of the invention is to reduce the technical-economic production cost of the adhesives, in particular to reduce the process costs for the adhesive production, a universal Sinsatsmöglichkeit of chlorine-containing thermoplastic polymers as a solid kosroonente of the adhesives to ensure and to improve the quality of the adhesives.

Explanation of the essence of the invention

The object of the invention is to provide solvent mixtures for the production of / adhesives which have good solubility for chlorine-containing thermoplastic polymers. «

According to the invention the object is achieved in that the solvent tetrahydrofuran 5 to 40 C-ew.-τα, preferably 10 to 30 wt. Ίδ, a straight-chain or branched

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th aldehyde of chain length C 4 to C 8 or an acetal derived from the aldehyde, enolacylates, diacylates or Dichloraldeiiydes is added,

Surprisingly, these solvent mixtures show excellent dissolving power for chlorine-containing thermoplastic polymers, so that it is easy to prepare high-quality adhesives based on these compositions. This is unexpected in that the said aldehydes and their derivatives are used alone, have a completely insufficient solubility and are therefore not known as solvents.

As aldehyde or derivable derivatives thereof, preference is given to 2-ethyl-propene (2) -al, 2-methyl-pentene (2) -al, 2-ethylhexene (2) -al, 1-i-diethoxy-2-ethyl-propene ( 2), 1, i-dimethoxy-2-methylpentene (2), 1,1-diethoxy-2-ethylhecenylene (2), 1-acetoxy-2-methylpentadiene (1,3), 1-acetoxy ~ 2-ethylhe: cadien- (1, 3), I ₃ 1-diaceto: cy-butane (butylidene diacetate), 1, i-diacetoxy-2-ethylidene- (2), 2, 3-bichloro-2 methylpentanal or 2,3-dichloro-2-ethylhexanal.

As chlorine-containing thermoplastic polymers z.3 »homopolymers, graft copolymers and copolymers of vinyl chloride with small amounts of other unsaturated compounds such. Propylene, vinyl acetate or vinylidene chloride. However, particularly preferred products are polyvinylchloride types with X values of 50 to 70, prepared by the bulk, suspension or emulsion polymerization methods. Also contemplated are chlorination products of polyolefins such as s, 3 "polyethylene, polypropylene and ethylene copolymers with P2r> op3rlsn and / or butylene, and of vinyl chloride polymers containing minor amounts of other unsaturated compounds, e.g. Propylene, vinyl acetate or vinylidene chloride. However, chlorinated folates with a chlorine content of 20 to 70% by weight are particularly suitable.

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The proportion of chlorine-containing thermoplastic polymers used is 5 to 20 percent by weight of the solution,

The preparation of the adhesives using the solvent mixtures according to the invention can be carried out according to the usual technologies. In many cases it can be dispensed with carrying out the dissolution process at elevated temperature bzTiV, under inert gas atmosphere,

Particularly advantageous is the ability to produce by means of the new solvent mixtures a variety of 'adhesives, which differ in their performance properties, to produce the same technology.

This is a significant economic advantage of the invention. "

The adhesives produced are completely residue-free and not gel-like, so that they have high technical properties and can be processed well.

To further improve the physical properties and the processability of the solvent-containing adhesives prepared according to the invention, these may contain other conventional additives in small amounts, such as processing aids, modifiers, stabilizers and antioxidants.

The application of adhesives is due to the large number of usable chlorine-containing thermoplastic polymers as a pesticide component in various technical fields for the bonding of half-suds and Pormteilen, consisting in particular of chlorine-containing thermoplastic polymers *.

So z "3. With these adhesives pipes, fittings, foils, plates and profiles are glued.

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Execution; sbeispiele

The invention will be explained below in several embodiments.

Example 1

In a stirred vessel with an intensive stirrer, a solvent mixture consisting of 17.4 parts by weight of 2-Kthylhexen- (2) ai and 69.6 parts by weight of 'tetrahydrofuran was given and at room temperature were 13 parts by weight solution-chlorinated PVC with a chlorinated content of 60% by weight and a K value of 60. ' The result was a residue-free adhesive.

To test the adhesiveness of the resulting adhesive, PVC sheets 2 mm thick were used. The panel ends were previously cleaned with methylene chloride. From the glued plates - draft shear test pieces were worked out. The test always resulted in material breakage, which indicates the good bond strength,

3eisuiel_2

Analogously to Example 1, an adhesive consisting of 8.7 parts by weight of 2-methylpentene (2) -al, 73.3 parts by weight of 'tetrahydrofuran and 13 parts by weight of o ₀ g, Iosungschio-' PVC was used to test the adhesiveness of the adhesive obtained. Hard PVC tubing with an outer diameter of 40 mm was used. The pieces of pipe that stuck together were made in the usual way with mandrel and calibration bush * ¹ ! expanded to an effective length of 2'o mm.

The test according to TGL 11 689 31. 1 of 5 Adhesive socket joints for creep behavior at 60 C water temperature and 11 MPa test period: the following service lives:

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Sample life in η

1 202

2 242

3 214

4 260

5. 225

Example 3

Analogously to Example 1, a gap-filling adhesive was prepared, in addition to 17.4 parts by weight of 2,3-dichloro-2-methylpentanal, 69.6 C-ew, parts tetrahydrofuran, 13 parts by weight of chlorinated PYC, in addition 2 wt . Parts of fumed silica. The chlorinated PVC used was chlorinated in the fluidized bed and has a chlorine content of 65.6% by weight and a K value of 65 ". The adhesive produced was used to bond pipes of chlorinated PYC with a diameter of 32 mm. The pipes were glued with fittings, whereby the piercing depth of the pipes was 22 mm. The parts to be bonded were cleaned with carbon tetrachloride. After the bonding, a load of 30 C water was applied. All pipe joints withstood a load of 8 MPa for a period of 1 000 hours,

Example 4

Analogously to Example 1, the following adhesive consisting of 3.7 parts by weight of 2, 3-dichloro-2-ethyihesanai, 73.3 parts by weight of tetrahydrofuran and 13 parts by weight of a chlorinated in the fluidized bed .PVC (K- Value 55, chlorine content 65.3% by weight) »The adhesive was used to glue 2 mm thick CPVG sheets. The sheets were previously cleaned with methylene chloride. From the glued plates, Z-gauge test specimens have been produced. The test of -10 test

value ": 7 -._" __ = 3.1 MPa - "0.6 ISSe.

 9-

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Example 5

Analogously to Example 1.Wehrde a solution mixture consisting of 8.7 parts by weight of 1,1-diethoxy ~ 2-ethylhe: cen- (2) and 78.3 parts by weight of tetrahydrofuran and at room temperature 13 parts by weight of a S-PVC, incorporated with a K value of 65 and 40 percent by weight, based on the amount of S-PVC, of a phthalic acid type plasticizer. This was a residue-free and flexible adhesive, this was used for bonding PVC soft-Polien (0.8 mm thickness), wherein the films were cleaned with methylene chloride before the adhesive application. At room temperature, the test revealed a maximum tensile shear strength value of XT max - ο ^ a - O, ο. ^ A

BeisT) iel_6

Analogously to Example 1, an adhesive was prepared consisting of 8.7 parts by weight of 1-aceto-2-ethylethyl; adiene (1, 3), 73.3 parts by weight, tetrahydrofuran and 13 parts by weight CPVC ,

The CPVC used was chlorinated in the fluidized bed and has a K - 'value of 58 and a chlorine content of 63% by weight. With dem'Klebstoff CPVC films were bonded together and ^υ in a 90 Ο · hot .45pro ζ entigen potash stored for 24 days. The examination of the stored films did not show a negative influence on the adhesive strength in comparison with the non-stored films.

Analogously to Example 1, an adhesive consisting of 13 C - W - Φ α - ΐ 1 on 1 1 → T; - Tar ^ prr! R_9_ ~ p7-liv '! ^, Pr! To? I -''? L 7 ά. C- ^ ' -

Parts Tetrahydrofuran, 13 parts by weight of an S-PVC with K-value 55 and 4 parts by weight of highly disperse silicic acid. The filler was used to glue PVC rolls of 90 mm. The Hchrstücke were in the usual way with Dorn-

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and Kalibrierbuchsen to an effective sleeve length of 45 on expanded. The test of 5 adhesive joints for creep behavior at 60 ° C water temperature and 2.4-MPa test voltage resulted in the following service life (PrU-.fung according to factory standard):

Sample life

1 220

2 -217

3 232

4 - 205

5 252

BeisT5iel_8

Analogously to Example 1, an adhesive was prepared which consists of the following constituents: 26.1 parts by weight of butylidene diacrylate, 60.9 parts by weight of tetrahydrofuran and 13 parts by weight of a solution-chlorinated PE having a chlorine value of 38 weight percent. The adhesive produced is residue-free and easy to spread. The adhesive was used to bond chlorinated PE based films. The areas to be bonded were cleaned with methylene chloride before applying the adhesive, ITa cn 1 000 h exposure in Senotestgerät 45.0. showed the Klebnahtgüte no negative changes-Example 9

Analogously to Example 1, an adhesive was composed by weight of 4 '- parts of 2-EthylprcOen- (2) -al, 76 weight parts by _a tetrahydrofuran and 20 wt, parts by mass of PVC made with a K-value of, the produced Adhesive is residue-free and of homogeneous consistency. This adhesive was used to bond 2 mm thick PVC sheets. The plate ends were cleaned with methylene chloride before application of the adhesive ».

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worked out test body. The test showed a maximum tensile shear strength at room temperature of

Example ^ IO

Analogously to Example 1, an adhesive was prepared which, in addition to 13 ₃ 4 parts by weight of 1,1-Diaceto3ty-2-ethylhexene (2), .73.6 parts by weight of tetrahydrofuran, and 13 parts by weight of a solution-chlorinated PVC with a chlorine value of 62% by weight and a K value of 59. The result was a \ J residue-free adhesive. The adhesive was used ..... ' to line a galvanized container with PVC soft film. Yor applied to the adhesive on the container. this was cleaned by sandblasting. The PVC-soft film was degreased with methylene chloride »The lining of the container is made according to the usual technologies» HTaoh a half-year operating life, the liner showed no shortage.

In the following, some Yergleichsbeisoiele be specified.

YergleichsbeisOisl.l

} "( In a stirred vessel with an intensive stirrer, a solvent mixture consisting of 67 parts by weight of tetrahydrofuran and 20 parts by weight of cyclohexanone was given and at room temperature, 13 parts by weight of an S-PYC having a K value of 65 were incorporated »The adhesive produced had a gall-like consistency.

To test the Klebfahigksit were 2 me. thick sheets of PYC glued together. The plate ends were previously cleaned with methylene chloride. From the bonded plates Zugscherprüfkörper were prepared.

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Examination of 10 test specimens-demonstrated the strong inhomogeneity of the bonds. The maximum tensile shear strength, measured at room temperature, was 8.2 .IvIPa, the scattering reaching 4.6 MPa. The break always occurred in the glued joint

Vergleichsbeispie1_2

In a stirred vessel with an intensive agitator, a solvent mixture consisting by weight of 70 wt _e parts by tetrahydrofuran and 15, -. Parts of cyclohexanone predetermined and at room temperature 15 parts by weight of a chlorinated in a fluidized bed PVC was attempted having a chlorine content of 66.2 .- to incorporate into the solvent mixture per und ent and a K = value of 65

Despite stirring for several hours, a sediment remained that had to be filtered off before use des.hergestellten adhesive. 2 mm thick CPVC plates were adhered to the next treated adhesive with the plate ends cleaned with methylene chloride prior to adhesive application. The sugar makers made of the glued plates were tested at a temperature of SO C. As a result, a maximum tensile shear strength of only 2.9-0.9 MPa could be determined.

Comparison example_3

In a stirred vessel with an intensive stirrer, 174 g of 2-ethylhexene (2) -al were given and tried to dissolve 26 g of a chlorinated in a fluidized bed PVC having a chlorine content of 66.6 percent by weight and a K value of 55 therein After several hours of stirring, the CPVC was only partially swollen, so that no adhesive could be produced.

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Claims (2)

- 13 - 2276 Claim to the invention 1. solvent mixtures for the preparation of adhesives based on ciiloriaaltiger thermoplastic polymers having a solvent mixture content of tetrahydrofuran from 60 to 95 C-ew.-prosent, characterized in that the solvent 'tetrahydrofuran 5 to 40 percent by weight, preferably 10 to 30 Gevr "-prosent, - a straight-chain or verzv / eister. Aldehyde of chain length C "4 to C 8 or an acetal derivable from the aldehyde, enoiacylates, diacylates or dichloroaldehydes is added" 2, solvent mixtures according to item 1, characterized in that as aldehyde or derivatives derivable therefrom, one of the KcmOonenten 2-3thyl "Dropen, - (2) -al, 2-I, iethylpenten- (2) -al, 2-3thylhe: that is ~ (2) -al _s 1, 1-diethos: y-2-ethylpropene (2), 1, 1 -dimethoxy-2-methylpentene (2), 1,1-diethoxy-2- ethylhe- (2), 1-Aceto-y-2-methylpentadiene (1,3), 1-acetoxy-2-ethylhexadiene (1,3) 1,1-diacetoxy-butane (butylidene diacetate), 1 , 1-diacetoxy-2-ethylhexene- (2), 2,3-, -o-1-theta-2-yl-2-ol;