DE2161941A1 - Polybutadiene diester - Google Patents

Description

Patent attorneys

Dr.-Ing. Wilhelm Reichel Dipl-Ing. Wolfgang Reichel

6 Frankfurt a. M. 1

Parkstrasse 13 6779

KOPPERS COMPANY, Inc. Pittsburg, Pennsylvania, VStA

Polybutadiene diester

The invention "relates to polybutadiene diesters with a monomeric vinyl crosslinking agents can be reacted and cured to form highly flexible rubber-like products, as well polymerizable masses which are cured to form highly flexible products with excellent physical properties can.

Butadiene homopolymers and copolymers with hydroxyl end groups have proven to be more advantageous physical Properties as valuable for the manufacture of urethane intermediate products for the manufacture of rubber goods with General purpose proven. Examples of objects that can be produced from such masses are elastomers, Seals, foams, potting compounds, coatings, adhesives, Sealants, solid propellants, encapsulants, and various other multi-.

Since the introduction of polybutadienes with Hydroxylandgruppen relatively recently, it has been shown that this Elastomers find a much broader area of application

209829/0885

if they had some of the compatibility properties of general-purpose elastomers. Further It has been found that despite the possibility of butadiene homopolymers or copolymers with hydroxyl end groups to crosslink by remaining butadiene double bond, difficulties arise when processing these elastomers, which on their high viscosity, low reactivity, their high consumption of initiator per crosslinking point as well the relatively poor physical properties of the final product. As an example of the latter Defect should be noted that the end product hardened to form a laminate could not be tested in some cases, because its strength was so low that separation of the layers was observed.

To improve the physical properties of the end product it is already known to add various polyfunctional compounds to the butadienes with hydroxyl end groups combine. In particular, there is much experimental material on the use of isocyanates in this context known. Elastomers made in a single-stage reaction from polybutadiene with hydroxyl end groups and toluene diisocyanate initially led to promising results; however, it decreases as a result of moisture absorption from the air and the resulting formation of urea and biuret structures gradually increase the hardness of the isocyanate material. This instability of the isocyanate elastomers makes them unusable for a wide range of applications.

It has now been found that various disadvantages which have hitherto been observed when using the polybutadienes mentioned, can be avoided.

The invention relates to a polybutadiene diester of the formula

DCO- (A) _x (B) ₇ -OCD ,

209829/0885

wherein (A) polymerized butadiene, (B) polymerized Styrene or polymerized acrylonitrile, y 0 or about 2.5 to about 24, χ about 18 to about 93 when y is 0, and about 14 to about 70 when y is about 2.5 to about 24, and D is the residue of an ethylenically unsaturated dicarboxylic acid or its Mean anhydride.

The polybutadiene diesters according to the invention, the butadiene homopolymers or copolymers which carry hydroxyl end groups through reaction with ethylenically unsaturated dicarboxylic acids or their anhydride can be obtained with a vinyl monomer implemented as a crosslinking agent or cured and shaped into objects with good properties.

In particular, the polybutadiene diesters according to the invention can be prepared by

(A) about 30 to about 35 mole percent of a hydroxyl terminated Butadiene homopolymer or copolymer with

(B) about 65 to about 70 mole percent of an ethylenically unsaturated Dicarboxylic acid or its anhydride

implements.

As will be explained in detail below, have the Polybutadiene diesters, which have been produced from the starting materials mentioned, unsaturated double bonds, the with vinyl monomeric crosslinking agents such as styrene, vinyl toluene etc., have them implemented. The crosslinked or cured product is a thermosetting material that has a combination of properties which makes it extremely suitable for objects such as electrical insulators, to be deformed. From the cured product according to the invention however, flexible coatings can also be produced.

209828/088

The above-mentioned hydroxyl-terminated polybutadiene used as a starting material can be represented by the structural formula

HO (A) _x (B) _y OH

where (A) polymerized butadiene either the product of the 1,2 addition 4CHo-CH-) or that of the

* CH = CH ₂

1,4 addition 4CH-CH = CH-CH Λ _ and ( _B ) polystyrene 4CH ₉ -CH-) or

^C 6 ^H 5 '

Polyacrylonitrile 4CHo-CH-) and χ about 18 to about 93 »when y is O

^d CN

and from about 14 to about 70 when y is from about 2.5 to about 24 are ψ .

The butadiene used as starting material is known and available on an industrial scale. Examples are the liquid polymers sold as "Poly B-D" by Arco Chemical Co. These liquid polymers are derived from Butadiene. A butadiene homopolymer of the formula given above for the starting material can be prepared by butadiene is reacted with lithium or sodium under conditions in which the metal derivative of the polymer has hydroxyl groups carrying reagents, such as water, is implemented.

A copolymer of those specified above for the starting material Formula can be prepared by mixing about 60 to about 90 weight percent butadiene with about 10 to about 40 weight percent styrene or acrylonitrile is reacted under conditions in which the metal salt of the polymer is formed and hydrolyzed with water will.

In general, the molecular weight of the polymers according to the formula given above for the starting material can vary within the range from about 1000 to about 5000 and the viscosity at 30 ^° C. within the range from about 100 to about 100,000 cps.

20S829 / 0885

The following table 1 shows the properties of exemplary butadiene homopolymers and copolymers with hydroxyl end groups specified.

Table 1

Monomers and Polymers with hydroxyl end groups 0.90 Butadiene /
Homopoly
merisat 0.90 Butadiene /
Styrene
Mixed poly
merisat • 0.91 Butadiene /
Acrylonitrile
Mixed poly
merisat properties
of the polymers Butadiene /
Homopoly
merisat (B) (C) (D) (A) 220 50 250 Monomer, wt. % 100 75 85 Butadiene 100 0.75 - 0.95 25th 0.95 - Styrene - 3200 - 2200 - 2100 15th Acrylonitrile - 1300 1050 1050 properties 0.05 0.05 0.05 d.Polymer 395 398 335 0.92 spec. weight Viscosity, poise 550 at 30 ^° C Hydroxyl number, 0.80 Milliequiv. / G 2400 Middle
Molecular weight 1250 Hydroxyl equiv. 0.05 Humidity,
Weight% 345 Iodine number

As the unsaturated acid or the anhydride that comes with a liquid Polymer according to the formula given above for the starting material to a polybutadiene diester according to the invention are implemented are an ethylenically unsaturated dicarboxylic acid or their anhydride. Examples of such materials are maleic anhydride, fumaric acid, chloromaleic acid, itaconic anhydride, Citraconic anhydride and mesaconic acid.

20 9 8 29/0885

The reaction of the unsaturated dicarboxylic acid and the diester according to the formula given above for the starting material can be carried out under conventional esterification conditions. Examples of suitable reaction temperatures and times are: heating to about 60 to about 180 ^° C. for about 1 to about 24 hours.

The acid number and the molecular weight of the polybutadiene diester formed can vary between about 20 to about 100 and about 1200 to about 5400, respectively. The acid number is preferred lower than about 80, while the molecular weight is in the range of about 1,500 to about 3,500.

Preferred polybutadiene diesters according to the invention are those which are prepared by reacting either maleic anhydride or itaconic anhydride and a butadiene homopolymer with a molecular weight between about 1000 and about 5000 or a butadiene / styrene or butadiene / acrylonitrile copolymer. Such copolymers can contain about 60 to about 90% by weight of monomeric butadiene and about 10 to about 40% by weight of the other monomer. The molecular weight of such copolymers can be between about 1000 and about 5000 and the viscosity at 30 ^° C. between about 100 and about 100,000 cps.

Polymerizable compositions according to the invention, which can be shaped and cured to give thermosetting objects, can be prepared by combining the unsaturated polybutadiene diester according to the invention with vinyl monomeric crosslinking agents which are capable of polymerization with the unsaturated diesters mentioned. Examples of such crosslinking agents which contain the CHp = CC group are styrene, vinyltoluene, alphamethylstyrene, chlorostyrene and tertiary butylstyrene. Other crosslinking agents can also be used . Styrene and vinyl toluene are preferably used as crosslinking agents. These vinyl monomers have relatively good reactivity and are relatively cheap.

209829/0885

The amount of crosslinking agent used can vary over a relatively wide range. For example, can a polymerizable composition about 20 to about 80 weight percent polybutadiene diester and from about 20 to about 80 weight percent crosslinking agent.

An important property of the polybutadiene diesters according to the invention is that they are used in conventional and mostly used vinyl monomeric crosslinking agents are very soluble. It is therefore possible to prepare solutions of low viscosity, which are curable with conventional free radical initiators. Examples of such solutions are those those formed from the diesters and vinyl monomers such as styrene, vinyl toluene, methyl methacrylate and triallyl isocyanurate are. The good solubility of the diesters according to the invention is of great advantage if from the polymerizable mass Objects are made by deforming.

Another important property of the polybutydiene diesters according to the invention is that liquid polymerizable masses, which they contain can be chemically thickened. The thickened masses can then be shaped into uncured polymer mats that keep their shape and light are manageable. In this way, the polybutadiene diesters according to the invention are very good for such deformation processes are used in which pre-thickened, curable Polyraerisatmatten with greater advantage than low viscosity liquid Solutions of the polymerizable mass are used.

Chemical thickening agents which are suitable for thickening polymerizable compositions containing an unsaturated polyester and a vinyl monomer as crosslinking agents can also be used for thickening the polymerizable composition according to the invention. Examples of chemical thickeners are those disclosed in U.S. Patents 2,628,209 and 3,390,205, although others can be used. The thickening of the mass can under certain conditions

209829 / 0Ö85

conditions can be accelerated by adding Y / ater. A chemical thickening agent containing a mixture of calcium oxide and calcium hydroxide thickens the polymerizable mass relatively quickly (see USA patent specification 3 431 320), which is a decisive advantage for some applications.

The amount of chemical thickener present in the polymerizable Mass according to the invention is contained, can be the same or similar to the amount as in previously known polymerizable compositions containing an unsaturated polyester and a vinyl monomer was used.

For example, a polymerizable composition according to the invention about 0.25 to about 10% by weight, based on the total weight the mass containing the thickener.

Of course, the chemical thickening is based on the polymerizable Composition according to the invention not based on a copolymerization between the polybutadiene diester and the crosslinking agent, and of course the chemical thickeners are other than fillers and are thixotropic Agents which are often used in polymerizable resinous compositions and which easily increase their viscosity.

The polymerizable mass can also contain other substances, often in polymerizable masses with a content of Vinyl monomer can be incorporated as a crosslinking agent and an unsaturated polyester. Examples of such substances are fillers, initiators or catalysts, crosslinking and stabilizing inhibitors, accelerators or Promoters, pigments, mold release agents and fibrous reinforcing agents.

As the fillers in the polymerizable composition may silica or silica in amounts up to about 70 wt.% Is used. Other conventional fillers, such as calcium

20 9829/0885

Calcium carbonate, clays and calcium silicate can be used.

An example of an initiator or catalyst that can be used is perbenzoic acid tertiary butyl ester in an amount of about 3%. Other common initiators are, for example, tertiary butyl hydroperoxide, benzoyl peroxide, succinic acid peroxide and cumene hydroperoxide.

Examples of crosslinking and stabilizing initiators that can be used are hydroquinone and tertiary butylcatechol.

Examples of accelerators or promoters that can be used are cobalt naphthenate, diethylaniline and dimethylaniline.

Thermosetting articles can be produced from the described polymerizable compositions by using generally known methods for curing and deforming thermosetting articles made from polymerizable compositions which contain a vinyl monomer as a crosslinking agent and an unsaturated polyester. Excellent results can be achieved by hardening and deforming the masses in matching metal molds. The pressure and temperature in the mold, as well as the molding time, depend on the particular mass used, as well as on the catalyst used and the size and thickness of the object to be produced. In order to achieve the best results, the deformation parameters must be determined experimentally. Generally, however, pressures between about 14 and about 700 kg / cm, temperatures between about 121 and about 177 ⁰ C and a duration of deformation can be applied from about 0.5 to etwa'10 minutes.

The invention is to be explained in more detail below with the aid of examples which illustrate the production of polybutadiene diesters concern according to the invention.

209829/0885

example 1

In one with a stirrer, a thermometer and a nitrogen Round-bottom flasks equipped with fine line tubes were 550 g (0.25 mol) of the butadiene homopolymer designated in Table 1 as B (sold under the trade name Poly B-D R-45M by Arco Chemical Co.) »49 grams (0.5 moles) of maleic anhydride and 1.20 g (0.2% by weight) lithium chloride introduced as an esterification catalyst and the whole thing for 1 hour at 100 to 105 ° C heated. The pale yellow viscous product was titrated in a mixture of equal parts acetone and hexane. It had one Acid number of 42.7, while the theoretical value is 48.

The procedure described in Examples 2 to 6 below is analogous to that described in Example 1.

Example 2

800 g (0.33 mol) of the butadiene copolymer identified in Table 1 as D (sold under the designation Poly B-D CN-15 by Arco Chemical Co.), 65.3 grams (0.66 moles) of maleic anhydride and 1.72 g of lithium chloride were reacted at 100 ° C for 1 hour. The product had an acid number of 43 (theoretical Value 45).

Example 3

700 g of the butadiene copolymer labeled C in Table 1 (sold under the designation Poly B-D CS-15 by Arco Chemical Co.) and 65.3 grams of maleic anhydride after conversion, a product with an acid number of 43 (theoretical value 51).

2098 2.9 / 0885

Example 4

400 g of the butadiene homopolymer designated A in Table 1 (sold under the designation Poly B-D R-15M by Arco Chemical Co.) and gave 24.5 g of maleic anhydride after conversion a product with an acid number of 31 (theoretical value 34).

Example 5

Instead of maleic anhydride, 56 g (0.5 mol) of itaconic anhydride were used in the process according to Example 1, and a product with an acid number of 45 (theoretical value 53) was obtained.

Example 6

400 g (0.125 mol) of the butadiene homopolymer designated A in Table 1 and 28 g (0.25 mol) of itaconic anhydride were ^{reacted for 45 minutes at 100 °} C., the product obtained had an acid number of 32.7 (theoretical value 33.9) .

The polybutadiene diesters according to Examples 1, 2 and 3 were mixed with the crosslinking agents given in Table 2 below in the amounts also given there, so that polymerizable compositions were obtained which were cured to give thermosetting castings 3.2 mm thick. The masses were ^{cured at 75 °} C. for 3 hours, at 135 ^° C. for 1 hour and at 150 ^° C. for 2 hours. Benzoyl peroxide was used as a curing initiator or catalyst in an amount of Λ% .

The properties of the castings are also given in Table 2.

209829/0 8 85

- 12 Table 2

Polymerizable Hasse Crosslinking agents Weight%
Monomer Polybutadiene
diester Monomer 30th
50
75
80
30th
50
80
30th
50
80
50
70
50
70 example 1
ti
Il
ti
ti
Il
Il
Il
Il
η
Example 2
Il
Example 3 Styrene
Il
Il
Il
Vinyl toluene
Il
ir
tert-butyl
styrene
It
It
Styrene
Il
Styrene
Il Example-
material
from table 1 1-A
1-B
1-C
1-D
1-E
1-F
1-G
1-H
1-K
1-L
2-A
2 B
3-A
3-B

2098 2 9/0 385

- 13 Continuation of Table 2

2,619-1

Example-
material
from table 1 Properties of the hardened masses Bending module
10 ⁺³ kg / cm ² 1-A
1-B
1-C
1-D
1-E
1-F
1-G
1-H
1-K
1-L
2-A
2 B
3-A
3-B Bending properties
(ASTM D-790) 13.86
16.31
8.68
13.72
8.75
12.46 Flexural strength
10 ⁺³ kg / cm ² 0.413
0.49
0.259
0.399
0.245
0.392

209829/0885

- 14 Continuation of Table 2

Example-
material
from table 1 Properties of the hardened masses tensile strenght
10 ⁺³ kg / cm ² Tensile module
10 ⁺³ kg / cm ² strain
% 1-A
1-B
1-C
1-D
1-E
1-F
1-G
1-H
1-K
1-L
2-A
2 B
3-A
3-B Tensile properties
(ASTM D-638) 0.014
0.063
0.21
0.182
0.014
0.028
0.168
0.007
0.042
0.259
0.021
0.161
0.084
0.168 0.077
0.889
16.31
19.32
0.07
0.133
10.78
0.049
0.266
15.19
1.071
10.36
1.652
14.28 30.9
459
243
39.3
128
375
309
84
408
2.4
95
251
398
47.2

209829/0885

- 15 Continuation of Table 2

Example-
material
from table 1 Properties of the hardened masses ' ■ Heat distortion
temperature
° C ( ⁰ F)
(ASTM-D-648) 1-A
1-B
1-C
1-D
1-E
1-F
1-G
1-H
1-K
1-L
2-A
2 B
3-A
3-B Notched impact
toughness
(ASTM D-256)
ft.-Ib./in 52 (126)
37 (99)
36 (96)
57 (134)
44 (112)
46 (115) 0.6
0.6
0.5
0.4
10.5
0.5
11.1
0.5

209829/0085

The physical properties of the hardened mass are expressed quite generally in the fact that the casting is soft, pliable and is clear and has a Barcol hardness of zero but has a measurable Shorer A beard. The flexibility of the clear castings was such that it could easily be rolled up into a cylindrical shape.

The percent elongation data in Table 2 for the cured Compositions which were produced from the diester according to Example 1 show that the tensile elongation of the cured composition initially increases with the amount of monomer in the mass, then a maximum value is reached and finally with further increasing Monomer concentration decreases. For example, the tensile elongation for Examples 1-A through 1-D is about 31, 459, 243 and 39% at styrene concentrations of 30, 50, 75 and 80%, respectively. Both Examples 1-E to 1-G using vinyl toluene the tensile elongation at 50% monomer concentration is higher than at the lower concentration of 30% (128%) and at that of 80% (309%). The same applies to the examples in which tertiary butyl styrene is used as the monomer.

The polybutadiene diesters according to Examples 1, 4, 5 and 6 were also combined with the crosslinking agents given in Table 3 below and formed into castings in the mold cured flat strip approximately 3.2 mm thick. The curing takes place, as in connection with above, with the castings described in Table 2, with the exception that 3% tertiary butyl perbenzoate is used as initiator will. The properties of the castings are listed in Table 3.

209823 / 038b

- 17 Table 3

)
Example-
material
from table 1 Polymerizable mass Polybutadiene
diester Crosslinking agent _w \ j t; w yo
Mono
meres hardness 1-M
1-N
1-0
1-P
4-A
5-A
5-B
5-C
5-D
6-A
6-B
6-C
6-D example 1
ti
11
It
Example 4
Example 5
Il
It
Il
Example 6
Il
Il
Il Monomer 30th
40
30th
50
40
30th
40
30th
50
30th
40
30th
60 90
80
83 Styrene
Vinyl toluene
Methyl methacrylate
Triallyl isocyanurate
Styrene
Styrene
Vinyl toluene
Methyl methacrylate
Triallyl isocyanurate
Styrene
Vinyl toluene
Methyl methacrylate
Triallyl isocyanurate

209829/08 8 5

- 18 Continuation of Table 3

Example-
material
from Tab. 1 Bending properties
(ASTM-790) Bending module
10 kg / cm Notched impact
toughness
(ASTM D-256)
ft.-Ib./in Heat defor
mung temperature
rature
(ASTM D-648)
⁰ C ( ⁰ F) 1-M
1-N
1-0
1-P
4-A
5-A
5-B
5-C
5-D
6-A
6-B
6-C
6-D Flexural strength
10 ⁺³ kg / cm ² 10.22
10.43
5.04
2.87
1.4
5.04
1.47
4.97
3.15
0.14
1.19 0.45
2.26
0.32
0.26
2.84
2.82
4.09
2.59
0.49
2.82
3.86
1.69
0.25 48 (119)
43 (110)
48 (118)
42 (108)
<24 «75)
42 (107)
36 (97)
41 (105)
42 (108)
<- 24 «75)
<24 (<75) 217
280
154
49
42
91
62
56
56
35
70

209829/0885

In the following Table 4, the electrical properties for 3.2 mm thick castings, the. From a composition of 50 wt% of the diesters according to Example 1 and 50% of styrene were prepared, assembled for both the wet and the dry state.

Table 4

characteristic ASTM D-150 dry wet Dielectric constant, 60 Hz 1 MHz 2.68 2.73 Loss factor, 60 Hz 2.90 2.44 1 MHz 0.0056 0.0063 ASTM D-149 0.0047 0.0056 Dielectric strength S.T. (1) -kV / mm (volts / mil) ASTM D-257 19.8 (503) 19.9 (505) Resistivity, ohm cm ι Spec. surface resistance, ohm 9x10 ¹⁴ 4.6x1O ¹² 2.64x10 ¹⁴ 1.9x10 ¹⁴

When comparing the properties listed in Table 4 with those of commercially available insulator plastics it can be seen that the values for the former are very high compared to the latter.

The examples given illustrate the combination of properties possessed by the compositions which can be prepared from the new class of compounds according to the invention. The masses can be produced from easily accessible starting materials and combined with easily accessible monomers as crosslinking agents and shaped into objects which have a combination of properties that make them useful for a wide variety of fields of application.

2 0 9 8 29/0305

The following two examples illustrate the inventive chemically thickened polymerizable masses.

Example 7

One mole of the butadiene homopolymer identified in Table 1 as B (sold as Poly BD R-45M by Arco Chemical Company) and 2 moles of maleic anhydride were reacted in the presence of monotertiary butylhydroquinone as a polymerization inhibitor. The temperature of the reaction ^{mixture was increased from 35 to 75 °} C. over 20 minutes and held at the last value for about 1 hour, after which the mixture was allowed to cool to room temperature. The product had an acid number of 39 »7. The polybutadiene diester obtained was used to produce a chemically thickened polymerizable mass with the following composition:

50 g of said diester

50 grams of styrene
1.05 g of magnesium oxide
0.5 g of water

The viscosity of the polymerizable composition was about 124,000 cps one day after its preparation and after 4 days 140000 cps.

Example 8

The polybutadiene diester according to Example 7 was used to prepare a thickened polymerizable composition which was used as Thickener contained calcium oxide and calcium hydroxide and was composed as follows:

50 g of the diester according to Example 7

50 grams of styrene
1 »45 g calcium oxide
1 »95 g calcium hydroxide
0.5 g of water

209829/0885

One day after the preparation of the mass, its viscosity was about 16,000,000 cps and after 4 days about 36,680,000 cps.

Typically, the above-mentioned thickened masses can be mixed with glass fibers and formed into mats, which to
a variety of shapes can be cured.

209829/0885

Claims (12)

Claims 1. Polybutadiene diester of the formula 0 0 DCO- (A) _x (B) _y -OCD wherein (A) polymerized butadiene, (B) polymerized χ y Styrene or polymerized acrylonitrile, y 0 or about 2.5 to about 24, χ about 18 to about 93 when y is 0, and about 14 to about 70 »when y is about 2.5 to about 24, and D denotes Radical of an ethylenically unsaturated dicarboxylic acid or its ™ anhydride. 2. polybutadiene diester according to claim 1, characterized, that y is 0 and A is 4CH ₂ -CH ^ or 4CH ₂ -CH = CH-CH ₂ -). CH = CH ₂ 3. polybutadiene diester according to claim 1, characterized in that that B is a styrene unit and y is about 2.5 to about 24. 4. polybutadiene diester according to claim 1, P characterized in that B is an acrylonitrile unit and y is about 2.5 to about 24. 5. polybutadiene diester according to any one of claims 1 to 4, characterized in that that D is the maleic anhydride residue. 6. polybutadiene diester according to any one of claims 1 to 4, characterized in that that D is the itaconic anhydride residue. 209829/0885 7. Process for the preparation of a polybutadiene diester according to claim 1, characterized in that under esterification conditions about 30 to about 35 mol% a butadiene homopolymer or copolymer containing hydroxyl end groups of the formula HO (A) (B) OH, in which A, B, χ and y are the χ y have the meaning given above, reacts with about 65 to about Mo 1% of an ethylenically unsaturated dicarboxylic acid or its anhydride. 8. A polymerizable composition containing a polybutadiene diester according to any one of claims 1 to 6 together with a vinyl monomer as a crosslinking agent. 9. Polymerizable composition according to claim 8, characterized in that that the polybutadiene diester with the vinyl monomer as a crosslinking agent is in solution. 10. Polymerizable mass according to claim 8 or 9 »characterized in that that the crosslinking agent is styrene or vinyl toluene. 11. Polymerizable mass according to one of claims 8 to 10, characterized in that that it also contains a chemical thickener. 12. A thermosetting article made by polymerizing any of the hats according to any one of claims 8 to 13 209829 / 0ä8b