JPH02229809A - Improved polybutadiene rubber - Google Patents

Abstract

PURPOSE:To obtain the subject rubber suitable for modifier of resin or rubber for tire having specific Mooney viscosity, etc., by polymerizing butadiene monomer using organic lithium-based catalyst and bonding resultant terminal lithium- activated polymer with polyfunctional treating agent. CONSTITUTION:Butadiene monomer is polymerized using organic lithium-based catalyst (e.g. reaction product of organic lithium compound and polyvinyl aromatic compound), preferably in solution polymerization method and resultant terminal lithium-activated polymer is bonded with polyfunctional treating agent (e.g. trichloromethylsilane) to afford the aimed rubber suitable for modifier of impact-resistance, gloss or rigidity, etc., of resin such as styrene resin having 30-80 Mooney viscosity, 20-60 centipoise solution viscosity, 10-40wt.% 1,2-vinyl bonding content and 10-18kg/cm<2> elastic modulus of crosslinked material by organic peroxide.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a new polybutadiene, particularly styrenic resins and polymethyl methacrylate resins [Prior Art] In recent years, rubber-modified styrenic resins, that is, impact-resistant With advances in manufacturing technology, the use of polystyrene-based resins has expanded to include housings and parts for household electrical equipment, parts for office equipment, daily necessities, and toys. Against this background, impact-resistant styrenic resins have recently been required to have various superior physical properties, and in particular, advanced styrene resins that balance impact resistance, rigidity, and appearance such as gloss are required. It has become a thing. As is well known, impact resistance can be improved by increasing the amount of gold in the rubbery polymer, but styrenic resins with increased rubbery polymer have improved impact resistance, but have lower rigidity. is significantly reduced, and the gloss is also reduced. On the other hand, improvements in rigidity and gloss can be achieved by reducing the spine content of the rubbery polymer or by making the particles of the rubbery polymer dispersed in the resin finer. There is a significant decrease in

Furthermore, in recent years, impact-resistant styrene-based resins have been attracting attention for their advancement into the application field of ABS resins (acrylonitrile-ptadiene-styrene resins), but the biggest problem is that
The problem is that the impact-resistant styrene resin has poor gloss. Recently, a method has been adopted to control the rubber particle size to a value of 1.7 μm or less in order to improve gloss, but the current situation is that the impact strength is poor and it is difficult to put it into practical use. In this way, since impact resistance, gloss, and rigidity are contradictory properties, it is difficult to obtain a styrenic resin that maintains high gloss and rigidity and also has excellent impact resistance. Conventionally, as a method to improve impact-resistant styrenic resin,
Specification of solution viscosity (Japanese Unexamined Patent Publication No. 5 8-4 9 34), Specification of the relationship between solution viscosity and Mooney viscosity (Japanese Patent Application Laid-open No. 5
3-44188), specification of molecular weight distribution (JP-A-54-15912), specification of the relationship between solution viscosity, tensile modulus and degree of swelling in organic peroxide cross-linked products (JP-A 1987-15912), -250021) and other methods have been proposed. [Problem to be solved by the invention] However, in these methods, it is difficult to improve the balance of gloss, road narrowing resistance, and rigidity.
This is not necessarily satisfactory. Also, JP-A-60-
In JP 250021, by using a specific rubbery polymer having a low tensile modulus as a toughening agent,
It is stated that impact-resistant styrenic resins with excellent impact resistance and rigidity can be obtained. [Means for Solving the Problems] Therefore, the present inventors aimed to develop a rubber-like polymer to obtain an impact-resistant styrenic resin with an excellent balance of impact resistance, rigidity, and gloss. In particular, we conducted extensive research on rubber-like polymers with low elastic modulus. As a result, they discovered that a resin with excellent impact strength and locking properties as well as good gloss can be obtained in the range where the elastic modulus of the rubbery polymer is significantly lower than that of conventional rubber. That is, the present invention provides; For example, a polyptadiene obtained by solution polymerization in the presence of an organolithium compound, which has an aH,2-vinyl bond amount of 10 to 40% by weight, and (b) a Mooney viscosity of ( ML..,) is 30-80, (
C) Viscosity of 5-layer repellent % styrene solution measured at 25°C (S
V) is in the range of 20 to 60 centipoise (cps), and (d) an elastic modulus measured under the specific conditions described below in the cross-linked polyptadiene per oxide crosslinked under the specific conditions described below. A rubber polymer suitable for improving styrene resins, characterized in that (E) is 10 to 18 kg/cd or less. The polybutadiene of the present invention is characterized by an extremely low modulus of elasticity compared to commercially available polybutadiene prepared using organolithium catalysts, and the polymerization technology for the polybutadiene requires some ingenuity. The present invention will be explained in more detail below. The specific polybutadiene of the present invention can be obtained by solution polymerization using a specific organolithium compound catalyst. Specific organolithium compound catalysts include, for example, 1,2-dilithio-1,2-diphenylethane and 1,4-dilithio-2-ethylcyclohexane, as shown in JP-A-57-40513. A mixture of a polyfunctional organolithium and an organic monolithium, or an organic seven-layer mixture,
There are reaction products containing both lithium and polyvinyl aromatic compounds (eg divinylbenzene). The polybutadiene of the present invention has a 1,2-vinyl bond amount of 10 to 40% by weight, preferably 10 to 25% by weight.
It is. If it is outside this range, the resulting resin will have insufficient impact resistance when used in an impact-resistant styrenic resin. The method for producing polybutadiene having such a specific microstructure may be any conventionally known method as long as it produces the above structure, but as a specific method, for example, dimethyl ether, dimethyl ether, Examples of polymerization methods include adding polar compounds such as ethers such as diethyl ether and tetrahydrofuran; thioethers such as dimethyl sulfide and diethyl sulfide; and amines such as dimethylethylamine and triethylamine. These vinyl bonds may exist uniformly in the molecule, or they may change gradually along the molecular length as shown in Japanese Patent Publication No. 48-875, or they may be bonded in blocks. It is sufficient that the total content is 10 to 40% by weight. In the polybutadiene of the present invention, the amount of 1,2-vinyl bond gold is 10 to 40% by weight. The amount of gold is 30-60% by weight. The polybutadiene rubber of the present invention has a Mooney viscosity (ML.
．． ．． ) is 30-80, and the 5-fold view% measured at 25℃
The styrene solution viscosity (SV) needs to be between 20 and 60 centipoise (cps). Mooney viscosity 30
If it is less than 80, the resulting resin will have poor impact resistance when used in an impact-resistant polystyrene resin, and if it is higher than 80, the appearance characteristics will be poor. In addition, the viscosity of 5% by weight styrene solution is 2
If it is less than 0 cps, the resulting resin will have poor impact resistance when used in impact resistant polystyrene resin, and if it is less than 60 cps.
If it is higher, the stiffness and appearance properties will be reduced. Furthermore, in the present invention, the elastic modulus of the organic peroxide crosslinked polybutadiene is required to be 10 to 18 kg/cd. Elastic modulus is less than IO kg/d or 18 kg
If it is higher than /cj, the resulting resin will have poor impact resistance when used in impact resistant polystyrene resins. Next, a method for measuring the properties of polybutadiene used in the present invention will be described. ■Mooney viscosity is ML1.4 (100°C). ■The viscosity of the 5% by weight styrene solution was measured at 25°C using a Canon fence type viscometer. ■The amount of 1,2-vinyl bond is measured using the Morello method (La c
himica EL' industry, 41
, 758 (1959)]. ■The elastic modulus as used in the present invention refers to the dynamic elastic modulus measured under specific conditions using a viscoelasticity measuring device for an organic peroxide crosslinked product that has been crosslinked and prepared under specific conditions. The specific conditions are described below; l) First, the preparation of a crosslinked product using an organic peroxide is carried out by the following method. 55 g of polybutadiene rubber and 0.055 g of dicumyl peroxide (0.1 part by weight per 100 parts by weight of rubber), an organic peroxide, are kneaded in the following apparatus. Kneading equipment: ■ Labo blast mill manufactured by Toyo Seiki Seisakusho (model LPM-2500-200) Kneading conditions: ■ Pre-mixing (sample input): 50°C, 10 rotations, 30 seconds, ■ Kneading: 50°C, 50 rotations, 2 minutes , This kneaded material is compression molded at a temperature of 160''C under a pressure of 200 kg/cj for 18 minutes to obtain a sheet of the organic peroxide crosslinked product. 2) Next, a sheet of this organic peroxide crosslinked product is formed. Cut a test piece from the product and measure the dynamic elastic modulus using a viscoelasticity measuring device. (Measurement conditions) ■Measurement model: ■VESF-111 model manufactured by Iwamoto Seisakusho ■Measurement method: Elongation deformation (constant initial load) , ■Measurement frequency: 1
00Hz, ■Initial load: 200g, ■Excitation amplitude: 3ooμ, ■Measurement temperature: 25℃, ■Sample dimensions: (width) 5■ (thickness) 2ffll×
(Length) 30 cm. As mentioned above, the polybutadiene rubber of the present invention has a lower elastic modulus of the organic peroxide crosslinked product than conventional general rubber. In order to produce such polybutadiene,
Some kind of ingenuity is required. As a specific method, for example, a butadiene monomer is polymerized using a reaction product containing at least an organic lithium compound and a polyvinyl aromatic compound as a catalyst, and after the polymerization is substantially completed, the generated terminal lithium activity is There are methods such as bonding polymers with polyfunctional processing agents. Furthermore, when polymerizing the butadiene monomer, it is preferable to perform the polymerization in a batch method, and to add the catalyst and butadiene in portions to react. The polyvinyl aromatic compounds mentioned here include, for example, divinylbenzene, 1.2.4-toIJ vinylbenzene, 1.
Examples include 3-divinylnaphthalene, 1,3.5-trivinylnaphthalene, 2.4-divinylbiphenyl, 3.5.4-trivinylbiphenyl, and divinylbenzene is particularly preferred. This divinylbenzene has o-, m-
% p- isomers, and divinylbenzene, which is a mixture of these isomers, can be used with sufficient effect.

On the other hand, examples of polyfunctional treatment agents include silane compounds [J, polyym, sci
, ^-1.3.93 (1965) ), carbonic acid diesters such as diethyl carbonate (Japanese Patent Publication No. 54-8716), divinyl aromatic compounds such as divinylbenzene (Japanese Patent Application Laid-Open No. 51-34290), Known compounds such as halogen compounds such as carbon chloride and tin compounds such as tetrachlorotin can be used. Each of these may be used alone or in combination of two or more. Furthermore, polar substances such as triethylamine, tri-n-butylamine, hexamethylphosphoramide, diethyl ether, and tetrahydrofuran may be added to the polymerization system. May be added. The polyptadiene of the present invention is produced by polymerizing butadiene monomers using an organolithium-based catalyst, and bonding the resulting terminal lithium-activated polymer with a polyfunctional treatment agent. , preferably 2031% by weight or more, more preferably 50 to 95% by weight, based on the total polymer. The amount of this bonded polymer component is adjusted by the ratio of the polyfunctional treatment agent to the organolithium catalyst.
Regarding the molecular weight distribution of the polybutadiene obtained in this way, the ratio (MW /n) is usually 2.2
~4.2, resulting in a polymodal shape.

As an example of producing polybutadiene used in the present invention, cyclohexane is charged in an autoclave, and tetrahydrofuran is added at a concentration of 50 pp to 4000 pp to cyclohexane.
p-Add. Next, 3 of the total amount of butadiene monomer used
After adding 0-70% of n-
Total amount of reaction product catalyst prepared from butyllithium, butadiene monomer, and divinylbenzene (amount of butadiene monomer used as n-butyllithium equivalent)
The reaction is started by adding 50% of Iθ (0.25-0.60 parts based on parts O). After the monomer reaction is completed, add the remaining monomer (7 of the total amount of butadiene monomer used)
0-30%) and the remaining catalyst (90-50% of the total catalyst used)
) to continue the reaction. After this reaction is complete, add 0.05 to 0.15 parts of silicon tetrachloride as a polyfunctional treatment agent, perform a coupling treatment, add a stabilizer, separate the cuttings, and obtain the desired polyptadiene. ．． [Examples] Some examples are shown below to show specific embodiments of the present invention, but these are intended to explain the gist of the present invention more specifically, and are not intended to limit the present invention. isn't it. Example 1 By the method shown below, with the amount of preparation and conditions shown in Table-1,
Polybutadiene was obtained. After washing and drying an autoclave with an internal volume of 100 liters and purging it with nitrogen, previously purified and dried cyclohexane and tetrahydrofuran were added, and then the dried initial putadiene monomer was added. Next, this solution was heated to the reaction starting temperature, and an initial catalyst was added. .

The reaction started. After the reaction is completed, the added catalyst, added butadiene monomer, etc. are added, and the reaction is restarted. After the reaction was completed, silicon tetrachloride was added and reacted for 20 minutes.

After the reaction, 2,
0.5 parts by weight of 6-di-t-4-methylphenol (BHT) was added to the polymer toO heavy flLaB, and the solvent was removed by heating with two rolls. Polybutadiene of Examples 1 to 6 and Comparative Examples 1 to 6 was obtained in the same manner as in Example 1 under the conditions shown in Table 1. Table 18 shows the method for preparing the organolithium substrate catalyst used to produce this polybutadiene. Table 18 Organolithium substrate catalysts A, B, and C were reacted and prepared using the preparation ratios and conditions shown in Table 1A, respectively. Commercially available divinylbenzene was used. This product was a mixture containing 57% divinylbenzene isomers, the balance being ethylvinylbenzene and diethylbenzene. Using the respective polybutadienes obtained in Examples 1 to 6 and Comparative Examples 1 to 6, impact-resistant styrenic resins were obtained by the bulk polymerization method described below. Polybutadiene 28-42
g, 672 to 658 g of styrene, 14 g of mineral oil, and 2.1 g of a stabilizer (Irganox 1076) were uniformly dissolved in their respective ratios. Transfer this to an Il separable flask equipped with a stirrer, and
Polymerization was carried out at 0°C for 3 hours, at 135°C for 2 hours, at 150°C for 2 hours, and at 170°C for 2 hours. Further at 230℃ 3
After heating for 0 minutes, unreacted materials were removed under reduced pressure, and the resulting polymer was pelletized using an extruder. ■Izod street strength is measured using JISK-7 1 test piece made by compression molding with a thickness of 3.2111.
Measured according to 10. ■Gloss is ASTM D
-638, using a dumbbell test piece injection molded, the glossiness (incidence angle 601) of the gate part and end gate part was measured in accordance with ASTM D-523 and averaged.
■The bending elastic modulus is 3.2 for the thickness created by compression molding.
- Measurement was performed according to ASTM D-790 using a test piece. The obtained results are shown in Reference Examples 1 to 6 and Reference Comparative Examples 1 to 6.
It is shown in As is clear from the results of Reference Examples 1 to 6, when impact-resistant polystyrene resin is polymerized using the polybutadiene of the present invention, a resin with excellent gloss and rigidity and at the same time improved impact resistance can be obtained. I found out that. On the other hand, as is clear from the results of Reference Comparative Examples 1 to 6, when impact-resistant polystyrene resin is obtained using polybutadiene other than the present invention, either the gloss or impact resistance properties is inferior. [Effects of the Invention] When the polybutadiene of the present invention is used in the production of styrenic resins, it can improve impact resistance without impairing the appearance and rigidity of the styrene resins. It is also used to improve the impact resistance of acrylic resins. Furthermore, if the polyptadiene of the present invention is used in place of the rubber conventionally used for tires, processability and bending resistance can be improved. As described above, the polybutadiene of the present invention is excellent as a modifier for resins and also exhibits excellent effects as a rubber for tires.

Claims (1)

[Scope of Claims] (a) Mooney viscosity is 30 to 80, (b) solution viscosity is 20 to 60 centipoise, (c) 1,
2-vinyl bond amount is 10 to 40% by weight; (d) the elastic modulus of the organic peroxide crosslinked product is 10 to 40% by weight;
18 kg/cm^2, and is characterized in that a butadiene monomer is polymerized with an organolithium catalyst, and the obtained terminal lithium active polymer is bonded with a polyfunctional processing agent.