JPH0437847B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a novel method for producing a dicyclopentadiene petroleum resin that has a high softening point and exhibits good solubility and color. More specifically, the present invention (1) heats a raw material (DCPD-based raw material) mainly composed of cyclopentadiene (CPD), dicyclopentadiene (DCPD), their alkyl substituted products, or a mixture thereof to a predetermined degree of polymerization. By a manufacturing method consisting of polymerizing, then (2) removing unreacted components, solvent, etc. by distillation etc., and then further (3) performing a second thermal polymerization in an open system in the absence of a solvent, This makes it possible to produce a dicyclopentadiene petroleum resin with a high softening point and excellent hue and solubility. (Prior art) A typical example of a conventionally known manufacturing method for dicyclopentadiene-based (DCPD-based) petroleum resin is to polymerize by heating at 260 to 278°C in the presence of a solvent, and then remove the solvent at a temperature below the polymerization temperature. Examples include the method of US Pat. No. 3,084,147, and the method of Japanese Patent Publication No. 47-43307, which involves heating polymerization in the temperature range of 260 to 350° C. in the presence of a solvent. Furthermore, Japanese Patent Publication No. 57-57048 describes a method for continuously producing DCPD-based petroleum resin in the absence of a solvent, and Japanese Patent Publication No. 47-43632 describes a method for producing DCPD-based petroleum resin with a narrow molecular weight distribution through two-step thermal polymerization. Methods of manufacturing the resins are each disclosed. These methods attempt to obtain a more homogeneous resin by using distillation of the solvent at a temperature below the polymerization temperature, a two-stage polymerization method, or a continuous polymerization method. However, with known methods, DCPD, which has a high softening point and good solubility and hue, is used as a resin for printing inks and paints.
It is difficult to obtain petroleum-based resins. Using DCPD raw materials of slightly high purity, using a relatively mild method for long periods of time (90 minutes at 260℃ and 270 minutes at 240℃)
(min) When polymerized in two steps, a resin with a relatively good color and a softening point of about 130°C has been obtained, but this method has limitations in the raw materials and polymerization conditions, as well as limitations in the softening point. In the two-stage polymerization method, the second stage polymerization is performed under milder conditions than the first stage polymerization, and the first stage polymerization is performed under milder conditions than the first stage polymerization.
It is thought that the aim is to increase the polymer yield by polymerizing the oligomers present in the step reaction product, and at the same time to improve the softening point by reducing the amount of oligomers present. There are limits to its effectiveness. On the other hand, normal methods can be used under harsher conditions (high temperature,
If polymerization is carried out over a long period of time), a resin with a higher softening point can be obtained, but it has the drawbacks of being dark in color and having poor solubility. As a method to compensate for these drawbacks, British Patent No. 1202802 employs a complicated method in which a high softening point resin with excellent hue is obtained by further hydrogenation after polymerization. (Problems to be Solved) The present inventors have completed the present invention as a result of extensive research into a method for producing resins with high softening points and excellent hue and solubility with good reproducibility. . That is, according to the method of the present invention, even if relatively low-purity DCPD raw materials are used as raw materials or polymerization is carried out under harsh conditions, the polymerization temperature is 100 to 220°C, more specifically 120 to 220°C. A DCPD petroleum resin having a high softening point and excellent hue and solubility can be obtained with good reproducibility. (Means for Solving the Problems) The present invention (1) thermally polymerizes DCPD raw materials to a predetermined degree of polymerization, and (2) distills the solvent and some or all monomers under negative or increased pressure. In this method, the desired petroleum resin can be obtained with good reproducibility by (3) further heating the polymerization solution in an open system to advance the polymerization reaction. Here, the order in which the steps are combined is also important, and if the steps are combined in any other order than the above, the desired excellent petroleum resin cannot be obtained satisfactorily. Note that the polymerized petroleum in the third step is not regulated by the polymerization temperature in the first step, but can be set according to the desired resin properties. To put the characteristics of the present invention in another way, in this production method, the reaction intermediate obtained by removing the solvent and some or all of the monomers from the polymerization liquid that has been polymerized to a certain extent has no color even if it is heated and polymerized at even harsher temperatures. This is based on the discovery that the polymer can be polymerized in a short period of time with at least little change, giving a resin with a higher softening point and excellent solubility. These facts are contrary to conventionally known techniques, and are a completely unexpected new manufacturing method. The method of the present invention will be explained in detail below. The raw material used in the present invention is a raw material (DCPD-based raw material) whose main component is CPD, DCPD, or an alkyl substituted product thereof, or a mixture thereof obtained by steam cracking of naphtha, etc.
Or the content of those alkyl substituents is 30wt
% or more, preferably about 50 wt% or more, and although not particularly strictly limited, it is generally desirable that these contents be high. This is because if the content of these alicyclic dienes is low, not only will the yield of the resulting resin decrease, making it uneconomical, but depending on the impurities contained, the hue of the resulting resin may deteriorate. This is because there is. On the other hand, when the content of these alicyclic dienes is high, it is possible to optionally dilute with a solvent as necessary. Refined raw materials with high purity generally have good hue, and therefore it is easy to obtain resin with excellent hue. Further, the DCPD raw material may contain an olefinic comonomer copolymerizable with these alicyclic dienes. These olefinic comonomers include aliphatic olefins such as isoprene, 1,3-pentadiene, butadiene, and butene, alicyclic olefins such as cyclopentene, and vinyl-substituted aromatics such as styrene and vinyltoluene. A mixture of the following may be mentioned. If the amount of olefins increases, the softening point of the resulting resin will decrease, or in the case of aromatic resins, the hue will deteriorate, and furthermore, problems that are contrary to the purpose of the present invention will occur, such as a decrease in resin yield. It is preferable that the concentration of these olefins is low, but 10wt of these cycloaliphatic dienes
It is acceptable if it is less than %. The first step of the invention is initiated under conventional polymerization conditions. That is, in the presence or absence of a solvent such as benzene, xylene, n-hexane or kerosene, using a fractional or continuous apparatus,
C., preferably in the temperature range of 240 to 300.degree. C., preferably in the presence of an inert gas such as nitrogen gas. Whether or not to use a solvent also depends on the content of alicyclic diene in the DCPD raw material; if the content is low, there is no need to use a solvent, and if the content is high, it is generally not necessary to use a solvent. Preferably, polymerization is carried out. The pressure of the reaction system may be any pressure that can maintain the system in a liquid phase, varies depending on the type or amount of solvent, and is not particularly specified. The polymerization time or residence time in the first step is set depending on the degree of polymerization desired for the first stage polymerization reaction product (intermediate resin), and the degree of polymerization is determined by the hue of the desired resin. That is, the polymerization in the first step is controlled to such an extent that the hue of the polymerization solution is not worse than the hue of the desired final product. Therefore, the first step is operated under relatively mild conditions, and the softening point of the resulting intermediate resin is also relatively low. The hue of the product liquid (mixture of monomer, solvent and intermediate resin) obtained in the first stage polymerization reaction is as follows:
In addition to the first-stage polymerization conditions (temperature, time), they vary depending on the composition and purity of the raw materials used, the type and amount of the solvent, etc., and cannot be uniformly defined. Numerically speaking, the polymerization conditions that satisfy the above requirements are in the range of 10 minutes to 10 hours at a temperature of 200 to 300°C; the higher the temperature, the shorter the time, and the lower the temperature, the longer the time. I need. Considering the preferred range of 240 to 300°C, the time is 10 minutes to 5 hours. Next, the solvent and some or all of the monomers in the second step are removed in a thin film evaporator or a reaction vessel in the first reaction step in the presence or absence of nitrogen or water vapor, either batchwise or continuously. The polymerization is carried out at a reduced pressure than that used in the first stage polymerization. The pressure used may be negative pressure or slight pressurization.
Further, pressurization may be used as long as the necessary solvent can be removed. The solvent may be removed by either distillation or evaporation. When removing the solvents, it is preferable to simultaneously remove part or most of the unreacted monomers. This is because these unreacted monomers are converted into a resin having a relatively low softening point in the next third step of polymerization. In the present invention, unreacted monomers refer to monomers in DCPD raw materials or oligomers such as dimers and trimers thereof. To describe the conditions of the solvent removal process numerically, the requirements governing the solvent removal process are pressure, temperature, and time, and these are interrelated. Generally preferred conditions include a substantial vacuum to a pressure of 5 kg/cm ² (G);
The temperature range is 100-300℃. The time required varies greatly depending on the equipment used, ranging from several seconds to several tens of seconds for a thin film evaporator and several minutes to several hours for a distillation pot, but it takes a long time at high pressure and low temperature, and a short time at low pressure and high temperature. Of course, that's a good thing. Usually, when using a polymerization tank or distillation vessel, the pressure is selected so that the temperature is 150 to 300°C for 15 minutes to 2 hours. Generally, in the solvent removal step, by lowering the pressure after the first stage polymerization is completed, the solvent and monomers evaporate and the latent heat of vaporization is used up. The latent heat of vaporization is supplemented as necessary by heating to remove the solvent and monomers to the desired extent. Once the solvent and monomers have been substantially removed, heating can increase the temperature of the system. Therefore, the final stage of the solvent removal step may be indistinguishable from the subsequent second stage polymerization step. This is why a high temperature range is included as the temperature for the solvent removal step. Further, the second stage polymerization conditions in the third step are selected depending on the softening point of the target resin and the properties of the resin. In particular, the polymerization temperature is not limited by the polymerization temperature of the first step as in conventional known techniques, and may be higher or lower than the polymerization temperature of the first step. The temperature of the second stage polymerization, which is the third step, is 200 to 300℃, and the polymerization time is
The time is 0.1 to 5 hours, preferably 0.2 to 3 hours. The pressure during this second stage polymerization is not particularly limited, but it is preferable to use a pressure near negative pressure or normal pressure from the viewpoint of the process. The polymerization in the third step is preferably carried out in an atmosphere of an inert gas such as nitrogen gas, and is carried out batchwise or continuously in the absence of a solvent.
This is done in an open system. This second-stage polymerization does not involve repolymerization of unreacted monomers, especially oligomers, as in the conventional two-stage polymerization method, but instead decomposes and repolymerizes the DCPD petroleum resin that has already formed to increase its molecular weight. It is thought that the This means that some or all of the unreacted monomers, including oligomers, are removed in the previous solvent removal step, and that the yield of resin obtained by the method of the present invention is of course lower than that of the conventional two-stage polymerization method. This is also recognized because the yield of resin obtained by the step polymerization method is the same or lower than that. The reason why a high-quality DCPD petroleum resin with a high softening point and excellent hue and solubility can be obtained by the method of the present invention is that a method of increasing the molecular weight by decomposition and repolymerization, which has not been used in the past, is adopted. This seems to be one of the reasons. Although the DCPD petroleum resin obtained by the method of the present invention has a high softening point of 120°C or higher as measured by the ring and ball method, it has excellent solubility in organic solvents. For example, one volume of petroleum resin obtained by the method of the present invention is Completely soluble in at least 1 volume of toluene at room temperature. A solution of 1 volume of this resin and 1 volume of toluene has a Gardner number of 10 or less and a good hue. (Effects of the Invention) As described above, according to the method of the present invention, it is possible to stably obtain a high softening point resin with an excellent pale yellow to yellow hue, and the resin is made of carbonized resin such as benzene, xylene or cyclohexane. It dissolves well in hydrogen solvents and is used in printing inks and paint resins, tackifiers, rubber compounding agents, etc. (Example) The present invention will be specifically described below with reference to Examples.
Each example includes a conventional known technique (Comparative Example A) for obtaining a resin by removing the solvent and unreacted monomers at a temperature below the polymerization temperature immediately after the completion of polymerization (first step), and a conventional technique (comparative example A) for polymerization (first step). After completion in the presence of solvent 2
Method for carrying out stage polymerization reaction (Step 1 → Step 3 →
Step 2 and Comparative Example B) are also shown. Example 1 shows an example in which the first step was carried out under relatively mild conditions (250° C. x 3 HR), and the third step was carried out at 270° C., which is higher than the known technology. The examples were treated under normal conditions (260°C x 2HR), and the third step was carried out at a polymerization temperature of 240°C, which was lower than the polymerization temperature of the first step.
An example conducted at a temperature of °C is shown. Therefore, Comparative Example-B
is a production method using a conventional two-stage polymerization technique. The example shows a production example in which the material was further treated under high temperature conditions (280°C x 0.5HR) and then the third step of polymerization was carried out at 280°C, which is higher than the known technology. The operating conditions of each example and comparative example and the properties of the obtained resin are summarized in Table 1. As is clear from Table 1, although the resins produced according to the method of the present invention have a somewhat lower resin yield than the conventional one-stage polymerization technique (Comparative Example A), they all have high softening points (Comparative Example A). 32-123℃ increase compared to A)
It shows comparable good hue and good solubility. On the other hand, in Comparative Example B, in which the second stage polymerization is carried out in the presence of a solvent, the resin yield is improved compared to Comparative Example A, but the hue (Gardner) is very poor, with the Gardner number increasing by 4 to 7. Increase in softening point is also 30-40
Is it moderate to °C (Comparative Examples-B, -B)?
Alternatively, the hue is good and at the same level, but the softening point increases only slightly (Comparative Example-B), and the method of the present invention is far superior. Furthermore, when producing a high softening point resin according to the method of Comparative Example B, depending on the selected conditions, some resins may be insoluble in toluene, which limits the production conditions. In addition, in each example and comparative example, DCPD-based raw materials (Gardner,
^1- ) was mixed with xylene and polymerized. The weight ratio of DCPD-based raw material/xylene was set to 60/40. The softening point of the obtained resin was determined by the ring and ball method, and the hue was 50vol%.
A toluene solution was measured by the Gardner method, and solubility was measured in a 50 vol% toluene solution. Note that the temperature and pressure values in the solvent removal step shown in the following Examples and Comparative Examples are the values at the final stage of the solvent removal step. In the laboratory operations in these examples, the removal of the solvent and monomers was completed in a relatively short period of time, about 10 minutes, and thereafter
It was possible to maintain the condition substantially as shown in . Example 600 g of DCPD raw material and 400 g of xylene were charged into 3 autoclaves equipped with a stirrer, and after purging the inside of the system with nitrogen gas, the reaction system was rapidly heated to 250°C and maintained at the same temperature for 3 hours. A one-step polymerization reaction was carried out. The pressure inside the system was 15Kg/cm ² (G). After the first step, the solvent and unreacted monomers were removed using a rotary evaporator under a nitrogen atmosphere and a slight pressure of 270°C. Approximately 30
It took several minutes. Subsequently, the same conditions were maintained for 90 minutes to carry out the third step of polymerization. The yield of the resin was 41 wt% based on the DCPD raw material, and it exhibited a softening point of 152°C and a hue (Gardner) of 8. Comparative Example -A A polymerization solution obtained in the same manner as in the first step of Example was heated under a nitrogen atmosphere using a rotary evaporator.
The mixture was maintained at 180° C. under a reduced pressure of 50 TORR for 1 hour to remove the solvent and unreacted monomers. Softening point 92℃,
320g of resin of hue 6 was obtained. Comparative Example -B A polymerization system obtained in the same manner as the first step of Example was subsequently heated to 270°C, held at the same temperature for 2 hours, and a second stage polymerization was performed in the presence of a solvent. (3rd step). After the polymerization was completed, the pressure was reduced to 50 TORR in a nitrogen atmosphere using a rotary evaporator, and the temperature was maintained at 180°C for 1 hour to remove the solvent and unreacted monomers. 430 g of resin having a softening point of 122°C and a hue of 10 was obtained. Examples -1 to -2 and Comparative Examples -A to -
B was carried out by a method corresponding to each of the above Examples and Comparative Examples. In the third step of Example 2, the second stage polymerization was carried out using an autoclave under pressure of 2 kg/cm ² (G) with nitrogen gas and flowing nitrogen gas. The manufacturing conditions are as shown in Table 1. In addition, Examples-1, -2 and Comparative Example-
The molecular weight distributions of A and -B measured by gel permeation chromatography (GPC) are shown in FIG. When processed by the method of the present invention, (1) a high molecular weight DCPD petroleum resin is newly generated in the third step, and the softening point increases. Furthermore, it can be clearly understood that (2) this tendency increases as the polymerization temperature in the third step is raised. As a more concrete example, the molecular weight distribution of Examples and Comparative Example-A by GPC is shown in FIG.
Note that when treated by the method of the present invention, the molecular weight distribution is somewhat broadened.

[Table] *2: In Example-1, a silicone oil bath was used,
Others used a glycerin bath.
*3: The hue of Comparative Example-B was measured on a suspension because the resin was not completely dissolved in toluene.
Reference Example 1 The same amount of xylene as the solvent (xylene) removed in the solvent removal process was added to the resin obtained in Comparative Example-A in an autoclave, and the mixture was pressurized with nitrogen gas and heated at 280°C for 20
Kg/cm ² (G) was maintained for 1.5 hours to carry out the second stage polymerization. After completion of the reaction, xylene was removed using a rotary evaporator at 180° C. under a reduced pressure of 50 TORR in a nitrogen atmosphere for 1 hour to obtain a resin with a softening point of 127° C. and a hue (Gardner) of 13. Note that the resin was soluble in toluene. As described above, even if a DCPD resin is produced using a combination order other than the one according to the present invention, it is not possible to obtain a resin with a high softening point and good hue as in the present invention.

[Brief explanation of drawings]

Figure 1 shows Examples-1 and -2 and Comparative Example-A.
This is a graph showing the molecular weight distribution by GPC of the resins obtained in and -B, where the horizontal axis shows the molecular weight in common logarithm, and the vertical axis shows relative strength. In the figure, 1 is Example-1 and 2 is Example-2. , 3 is a graph for Comparative Example-B and 4 is a graph for Comparative Example-A,
FIG. 2 is the same graph as FIG. 1 for Examples and Comparative Example-A, and in the figure, 1 is a graph for Example and 2 is a graph for Comparative Example-A.

Claims (1)

[Claims] 1 A raw material containing cyclopentadiene or dicyclopentadiene as a main component is heated at a temperature of 200 to 300°C for 10 to 10 minutes in the presence or absence of a solvent.
dicyclo, which is characterized by thermally polymerizing for a period of time, lowering the pressure, removing unreacted components and solvent from the obtained polymer solution, and further thermally polymerizing this polymer at a temperature of 200 to 300°C for 0.1 to 5 hours. Method for producing pentadiene petroleum resin.