Manufacturing method of petroleum resin for hot melt adhesive and manufacturing method of hydrogenated petroleum resin

Abstract

Provided is a method for producing a petroleum resin using a tube-type reactor, the method producing a petroleum resin that exhibits good properties as an adhesive component for a hot-melt adhesive which has a narrow molecular weight distribution and a high softening point, and which exhibits good adhesive capability and also has little insoluble matter.　A method for producing a petroleum resin using a raw material containing at least a cyclopentadiene-based component (A) and a styrene-indene-based aromatic component (B), by thermal polymerization of the raw material, the method being characterized by having a first polymerization reaction step for thermally polymerizing the raw material using a loop reactor, and a second polymerization reaction step for thermally polymerizing the polymerization product obtained in the first polymerization reaction step using a plug flow reactor.

Description

[Technical field]

[0001] The present invention relates to a method for producing a petroleum resin used as a tackifier for hot melt adhesives, and a method for producing a hydrogenated petroleum resin by adding hydrogen to the petroleum resin. [Background technology]

[0002] Hot melt adhesives are being used in a wide range of fields due to their excellent properties such as high speed application, fast curing, solventlessness, barrier properties, energy saving, and economic efficiency. Common hot melt adhesives include compositions in which a tackifier and / or plasticizer are blended with a base polymer such as a styrene-isoprene-styrene block copolymer or its hydrogenated product. As the tackifier, hydrogenated petroleum resins are used, which are obtained, for example, by hydrogenating a petroleum resin obtained by thermally polymerizing a raw material containing a cyclopentadiene compound and a vinyl aromatic compound. Therefore, various methods for producing petroleum resins or hydrogenated petroleum resins have been proposed (see, for example, Patent Documents 1 to 4). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 61-143413 [Patent Document 2] Japanese Patent Application Publication No. 63-260913 [Patent Document 3] Japanese Patent Application Publication No. 2-289603 [Patent Document 4] JP 2015-124246 A Summary of the Invention [Problem to be solved by the invention]

[0004] When a petroleum resin is produced by thermally polymerizing a raw material containing a cyclopentadiene compound and a vinyl aromatic compound, the polymerization reaction has conventionally been carried out using a batch-type or continuous-type apparatus, as shown in Patent Documents 1 and 2 above. The reactors used in both batch and continuous systems are tank-type reactors equipped with a stirrer. The batch polymerization reaction has the advantage that the residence time is uniform, so that a high-softening-point grade resin with a relatively narrow molecular weight distribution (so-called sharp molecular weight distribution) can be obtained, but it has the disadvantage of low production efficiency. In addition, after producing a resin by polymerization reaction, the batch system requires a washing process and other steps when moving on to the next production, which is time-consuming. On the other hand, continuous polymerization reactions can overcome the poor production efficiency of batch polymerization, but it is difficult to control the molecular weight, and it is difficult to produce a resin with a high softening point and a sharp molecular weight distribution. In addition, the tank-type reactor equipped with an agitator used in the above-mentioned patent document has the following problems. Since the polymerization reaction is carried out at high temperature and pressure, a tank-type reactor having a large diameter requires a large plate thickness, which imposes restrictions on the material and manufacturing. In the case of a commercial plant, the weight of the reactor and the frame and foundation for mounting the reactor are large, which makes installation and maintenance of the reactor complex. Furthermore, since tank-type reactors have an agitation device, when reactions are carried out at high temperatures and pressures, it is necessary to prevent leakage of liquid, gas, etc. from the rotating agitation shaft, which necessitates high manufacturing precision for the equipment, and there are also high demands for maintenance. Considering the high temperature and high pressure reaction field, it is preferable to use a tubular reactor rather than a tank type reactor in the production of petroleum resins. It is desirable to produce petroleum resins using tubular reactors, as this allows for larger facilities and more practical plant designs, and also reduces costs and maintenance burdens. However, when trying to produce petroleum resins using a tubular reactor, it is difficult to carry out the reaction at a constant temperature while removing the heat generated in the thermal polymerization reaction, especially when using raw materials containing a large amount of reactive components. Therefore, at the practical level, petroleum resins that have a narrow molecular weight distribution, a high softening point, good adhesive performance, and little insoluble matter and are of good quality as an adhesive component for hot melt adhesives have not been obtained.

[0005] Therefore, the present invention aims to provide a method for producing a petroleum resin using a tubular reactor, which produces a petroleum resin that has a narrow molecular weight distribution, a high softening point, good adhesive performance, and little insoluble matter, and that exhibits good quality as an adhesive component for hot-melt adhesives. [Means for solving the problem]

[0006] As a result of extensive investigations aimed at solving the above-mentioned problems, the present inventors have found that the petroleum resin intended by the present invention can be produced by using two types of tubular reactors, namely a loop reactor and a plug flow reactor, first subjecting a raw material to a thermal polymerization reaction in the loop reactor, and then further subjecting the obtained polymerization reaction product to a thermal polymerization reaction in a plug flow reactor, thereby completing the present invention.

[0007] That is, the present invention includes the following aspects. [1] A method for producing a petroleum resin by subjecting a raw material containing at least a cyclopentadiene-based component (A) and a styrene-indene-based aromatic component (B) to a thermal polymerization reaction, comprising: a first polymerization reaction step of thermally polymerizing the raw material using a loop reactor; and a second polymerization reaction step of thermally polymerizing the polymerization reaction product obtained in the first polymerization reaction step using a plug flow reactor. [2] The method for producing a petroleum resin according to the above [1], wherein a ratio (x / z) of the reaction residence time (x) of the loop reactor to a total reaction residence time (z) obtained by adding up the reaction residence time (x) of the loop reactor in the first polymerization reaction step and the reaction residence time (y) of the plug flow reactor in the second polymerization reaction step is 0.1 to 0.9. [3] The method for producing a petroleum resin according to the above [2], wherein a ratio (x / z) of the reaction residence time (x) of the loop reactor to a total reaction residence time (z) obtained by adding up the reaction residence time (x) of the loop reactor in the first polymerization reaction step and the reaction residence time (y) of the plug flow reactor in the second polymerization reaction step is 0.2 to 0.8. [4] The method for producing a petroleum resin according to the above [2] or [3], wherein the total reaction residence time (z) is 30 to 180 minutes. [5] The method for producing a petroleum resin according to any one of the above [1] to [4], wherein the cyclopentadiene-based component (A) is contained in an amount of 50 to 90% by weight based on the raw material, and the styrene-indene-based aromatic component (B) is contained in an amount of 10 to 50% by weight based on the raw material. [6] The method for producing a petroleum resin according to any one of the above [1] to [5], wherein in the styrene-indene aromatic component (B), a weight ratio (C-1 / C-2) of the styrenes (C-1) contributing to the thermal polymerization reaction to the indenes (C-2) contributing to the thermal polymerization reaction is 0.6 to 4.0. [7] The method for producing a petroleum resin according to any one of the above [1] to [6], wherein the polymerization reactions in the first polymerization reaction step and the second polymerization reaction step are carried out at a temperature of 230 to 320°C. [8] A method for producing a hydrogenated petroleum resin, comprising a step of hydrogenating the petroleum resin obtained by the method for producing a petroleum resin according to any one of the above [1] to [7]. Effect of the Invention

[0008] According to the present invention, there can be provided a method for producing a petroleum resin using a tubular reactor, which produces a petroleum resin that has a narrow molecular weight distribution, a high softening point, good adhesive performance, and a small amount of insoluble matter, and that exhibits good quality as an adhesive component for hot melt adhesives. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing an example of the structure of a loop reactor. [Diagram 2] FIG. 2 is a schematic diagram showing an example of the structure of a plug flow reactor. [Diagram 3] FIG. 3 is a schematic diagram showing an example of the structure of a tank-type reactor. [Figure 4] FIG. 4 is a schematic diagram showing an example of a facility for carrying out the first and second polymerization reaction steps for producing a petroleum resin by the petroleum resin production method of the present invention. [Diagram 5] FIG. 5 is a schematic diagram showing another example of the facility for carrying out the first and second polymerization reaction steps for producing a petroleum resin by the petroleum resin production method of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The method for producing a petroleum resin of the present invention will be described in detail below. However, the description of the constituent elements described below is an example of one embodiment of the present invention, and the present invention is not limited to these contents.

[0011] (Production method of petroleum resin) The method for producing a petroleum resin of the present invention comprises: a first polymerization reaction step of thermally polymerizing the raw material using a loop reactor; and a second polymerization reaction step in which the polymerization product obtained in the first polymerization reaction step is thermally polymerized in a plug flow reactor. Before describing the first and second polymerization steps in the method for producing a petroleum resin of the present invention, the raw materials and the reactor used in the present invention will be described.

[0012] <Raw materials> The raw material used in the process for producing a petroleum resin of the present invention contains at least a cyclopentadiene-based component (A) and a styrene-indene-based aromatic component (B). The styrene-indene aromatic component (B) means that it contains both a styrene aromatic component (B-1) and an indene aromatic component (B-2).

[0013] The cyclopentadiene component (A) used as a raw material in the present invention includes alicyclic diene compounds such as cyclopentadiene and its multimers or their alkyl-substituted products. This cyclopentadiene component (A) may contain one or more of the alicyclic diene compounds, or may be a cyclopentadiene fraction (CPD fraction) containing a cyclopentadiene component obtained by steam cracking of naphtha or the like. This CPD fraction may contain an olefinic monomer or a multimer thereof that is copolymerizable with the alicyclic diene compound. Examples of such olefinic monomers include aliphatic dienes such as isoprene or piperylene. Of the cyclopentadiene components (A) used as a raw material in the present invention, the cyclopentadienes (A-1) that contribute to the reaction include cyclopentadiene, lower alkyl-substituted cyclopentadienes such as methyl- and ethyl-substituted cyclopentadienes, and their dimers and trimers, as well as co-dimers of cyclopentadiene with monomers such as isoprene and piperylene, and monomers such as isoprene and piperylene themselves, and dimers and trimers of these monomers.

[0014] The styrene-indene aromatic component (B) also used as a raw material includes a styrene aromatic component (B-1) and an indene aromatic component (B-2), which are C9 aromatic hydrocarbons and have ethylenic unsaturated bonds. When a mixture of the styrene aromatic component (B-1) and the indene aromatic component (B-2) is used as a raw material, the so-called C9 fraction, which is a by-product of steam cracking of naphtha, etc., can be used. Among the styrene-indene aromatic components (B), the styrenes (C-1) that contribute to the thermal polymerization reaction are compounds with an olefin attached to the aromatic ring, such as styrene, vinyltoluene, divinyltoluene, etc. Also, the indenes (C-2) that contribute to the thermal polymerization reaction are compounds with an indene skeleton, such as indene, methylindene, and dimethylindene.

[0015] In the styrene-indene aromatic component (B), the weight ratio (C-1 / C-2) of the styrenes (C-1) contributing to the thermal polymerization reaction to the indenes (C-2) contributing to the thermal polymerization reaction is not particularly limited and can be appropriately selected depending on the purpose, but is preferably, for example, 0.6 to 4.0. From the viewpoint of the petroleum resin yield, it is preferably 0.6 or more, and from the viewpoint of compatibility with the base polymer used when the product is used, it is preferably 4.0 or less.

[0016] In addition to the reaction raw materials to be subjected to the polymerization reaction, a solvent may be added to the raw materials used in the present invention, if necessary, in order to appropriately dilute the reaction raw materials. The solvent is not particularly limited and can be appropriately selected depending on the purpose. Examples of the solvent include pentane, hexane, heptane, benzene, toluene, xylene, and unreacted light fractions contained in the thermal polymerization reaction product. In addition, the total amount of the compounds contributing to the reaction, i.e., cyclopentadienes (A-1), styrenes (C-1), and indenes (C-2), relative to the mixture of the raw materials and the solvent is preferably 30 to 95% by weight, more preferably 35 to 90% by weight, and even more preferably 40 to 85% by weight. If the total amount is equal to or greater than the lower limit of the above-mentioned preferred range, the problem of the amount of petroleum resin produced being reduced due to the amount of compounds contributing to the reaction being too small, which is economically undesirable, can be effectively prevented. In addition, if the total amount is equal to or less than the upper limit of the above-mentioned preferred range, the problem of the viscosity being too high due to the amount of compounds contributing to the reaction being too large, which results in insufficient fluidity in the device, can be effectively prevented. In addition, the weight ratio of the amount of the cyclopentadienes (A-1) to the combined amount of the styrenes (C-1) and indenes (C-2), i.e., the amount of A-1 / (amount of C-1+amount of C-2), is preferably 0.1 to 20.

[0017] The cyclopentadiene component (A) is preferably contained in an amount of 50 to 90% by weight based on the raw materials. The styrene-indene aromatic component (B) is preferably contained in an amount of 10 to 50% by weight based on the raw material. The content of the styrene-indene aromatic component (B) refers to the combined content of both the styrene aromatic component (B-1) and the indene aromatic component (B-2). It is more preferable that the cyclopentadiene-based component (A) is contained in an amount of 50 to 80% by weight relative to the raw materials, and the styrene-indene-based aromatic component (B) is contained in an amount of 20 to 50% by weight relative to the raw materials, and it is even more preferable that the cyclopentadiene-based component (A) is contained in an amount of 50 to 70% by weight relative to the raw materials, and the styrene-indene-based aromatic component (B) is contained in an amount of 30 to 50% by weight relative to the raw materials.

[0018] <Reactor> In the present invention, a tubular reactor such as a loop reactor and a plug flow reactor is used. A tubular reactor is a type of reactor in which a fluid flows through a tube, and a static mixer may be provided in the reactor to promote mixing of the polymerization reactants. A schematic diagram showing an example of the structure of a loop reactor is shown in Figure 1. In a loop reactor 11, raw materials are introduced into a tubular reactor body 13 through an inlet pipe 12 and subjected to a reaction. The polymerization reaction product is discharged from the tubular reactor body 13 through an outlet pipe 16. In other words, the loop reactor 11 is a reactor in which raw materials and, if necessary, a solvent are continuously introduced into the tubular reactor main body 13, the raw materials are polymerized while circulating inside the tubular reactor main body 13, and the polymerization reaction product is continuously withdrawn from the tubular reactor main body 13, thereby continuously carrying out a polymerization reaction. The loop reactor 11 also includes a pump 14 and a cooler 15 . Next, a schematic diagram showing an example of the structure of a plug flow reactor is shown in Figure 2. In a plug flow reactor 21, raw materials are introduced into a tubular reactor body 23 through an inlet pipe 22 and subjected to a reaction. The polymerization reaction product is discharged from the tubular reactor body 23 through an outlet pipe 26. In other words, the plug flow reactor 21 is a reactor equipped with a tubular reactor body 23, into which a raw material (in this invention, the polymerization reactant taken out from the loop reactor) and, if necessary, a solvent are continuously introduced from one end, and the polymerization reactant is further polymerized while being circulated toward the other end, and the polymerization reactant is continuously withdrawn from the other end. The plug flow reactor 21 includes a pump 24 and a cooler 25. In addition, the tubular reactor body 23 is covered with a jacket 27 and is cooled by a coolant in the jacket 27. The coolant is circulated by the pump 24 and cooled by the cooler 25. In FIG. 2, a straight tubular reactor body 23 is shown as an example, but it may be in a coiled shape.

[0019] As shown in Figures 1 and 2, a tubular reactor, in which a reaction occurs while a fluid flows through a tube, has a different structure from a conventional tank reactor, in which a reaction occurs in a stirred tank. A schematic diagram showing an example of the structure of a conventional tank reactor is shown in Fig. 3. In a tank reactor 31, raw materials are introduced into a tank reactor main body 33 through an inlet pipe 32 and subjected to a reaction. A polymerization reaction product is discharged from the tank reactor main body 33 through an outlet pipe 36. The tank reactor 31 has a pump 34, a cooler 35, a jacket 37, and an agitator 38.

[0020] <Residence time> In loop and plug flow reactors, residence time (HRT) refers to the average time that a fluid (e.g., liquid) that enters the reactor remains in the reactor. For example, a larger residence time (HRT) means that the material contained in the liquid undergoes a longer reaction time. The residence time (HRT) (hr) can be calculated by the following formula (1).

number

[0021] <Polymerization process> As described above, the method for producing a petroleum resin of the present invention includes a first polymerization reaction step in which a thermal polymerization reaction is carried out using a loop reactor, and a second polymerization reaction step in which the polymerization reaction product obtained in the first polymerization reaction step is thermally polymerized using a plug flow reactor. The present invention is characterized in that the raw materials are polymerized using two types of tubular reactors, a loop reactor and a plug flow reactor, and that the polymerization reaction is carried out using the loop reactor before the plug flow reactor. As a result, as is clear from the results of the following examples, it is possible to produce a petroleum resin that has a narrow molecular weight distribution, a high softening point, good adhesive performance, and little insoluble matter, and is of good quality as an adhesive component for hot melt adhesives. If the polymerization reaction is carried out only in a loop reactor, a petroleum resin with a wide molecular weight distribution is obtained, which does not exhibit good adhesive properties as an adhesive component.On the other hand, if the polymerization reaction is carried out only in a plug flow reactor, it becomes difficult to control the heat generation, and the polymerization proceeds too far, resulting in the generation of large amounts of insoluble matter, and therefore it is not possible to obtain a high-quality petroleum resin. The present inventors have found that by carrying out the polymerization reaction in the order of a loop reactor and a plug flow reactor, it is possible to produce a petroleum resin that has a narrow molecular weight distribution and exhibits good adhesive performance while suppressing the generation of insoluble matter. In the loop reactor, where the temperature control of the exothermic reaction is easy, the polymerization reaction of the raw material is partially advanced, thereby preventing a sudden exothermic reaction in the subsequent plug flow reactor. In addition, in the polymerization reaction, the molecular weight increases significantly in the latter half of the reaction, and therefore uniform polymerization is carried out by the plug flow reactor, which has a narrow residence time distribution, so that a petroleum resin with a narrow molecular weight distribution can be produced. The object of the present invention cannot be achieved by using a loop reactor and a plug flow reactor in combination. If the polymerization reaction is carried out in the plug flow reactor and then the loop reactor, as is clear from the results of the Reference Examples below, a large amount of insoluble matter is generated and the molecular weight distribution becomes broad, making it impossible to produce a high-quality petroleum resin. In addition, the petroleum resin production method of the present invention suppresses the generation of insoluble matter, thereby suppressing the fouling phenomenon in which insoluble matter adheres to and accumulates inside the reactor tubes. If clogging or temperature unevenness occurs inside the tubes due to fouling, it becomes difficult to steadily supply petroleum resin, and frequent operation stoppages and disassembly and cleaning of the reactor are necessitated, reducing production efficiency. Therefore, the present invention makes it possible to stably produce petroleum resin with high production efficiency and without the burden of maintenance.

[0022] In the petroleum resin production method of the present invention, the ratio of the reaction residence time (x) of the loop reactor to the total reaction residence time (z) obtained by adding up the reaction residence time (x) of the loop reactor in the first polymerization reaction step and the reaction residence time (y) of the plug flow reactor in the second polymerization reaction step is preferably 0.1 to 0.9. This is because, in order to fully exert the respective effects of using the loop reactor and the plug flow reactor, it is necessary to use each reactor for a certain period of time. The ratio (x / z) of the reaction residence time (x) in the loop reactor to the total reaction residence time (z) is more preferably 0.2 to 0.8, and further preferably 0.3 to 0.8.

[0023] The total residence time and the temperature during the polymerization reaction in the first and second polymerization reaction steps can be appropriately adjusted depending on the constituents of the raw materials and their ratios, but the total residence time is preferably, for example, 30 to 180 minutes, more preferably 45 to 160 minutes. If the residence time is short, the polymerization does not proceed sufficiently and sufficient adhesive performance is not exhibited. If the residence time is long, the polymerization proceeds too much, resulting in an increase in insoluble matter due to excessive polymerization, making it difficult to continue operating the device. The temperature during the polymerization reaction is, for example, preferably from 230 to 320°C, and more preferably from 240 to 300°C.

[0024] FIG. 4 is a schematic diagram showing an example of an equipment for carrying out the first and second polymerization reaction steps for producing a petroleum resin by the petroleum resin production method of the present invention. In the present invention, the number of reactors, such as loop reactors or plug flow reactors, is not particularly limited and can be appropriately selected depending on the purpose. For example, as long as polymerization is carried out in a loop reactor before polymerization in a plug flow reactor, a plurality of loop reactors may be used for polymerization. FIG. 5 is a schematic diagram showing another example of the facility for carrying out the first and second polymerization reaction steps for producing a petroleum resin by the petroleum resin production method of the present invention, in which a plurality of loop reactors are used.

[0025] The blended raw materials are thermally copolymerized in the presence or absence of a solvent at a temperature range of 230 to 320° C. for 30 to 180 minutes under a pressure sufficient to maintain the polymerization components in a liquid phase.

[0026] The petroleum resin obtained by the above-mentioned method for producing a petroleum resin of the present invention may then be subjected to a step of removing unreacted and low polymerized components, or, if necessary, the solvent. For example, the step of removing unreacted and low polymerized components, etc., may be performed by reduced pressure distillation or steam distillation. The petroleum resin thus obtained may be subjected to a further hydrogenation step, which makes it possible to effectively use the petroleum resin as an adhesive component for hot melt adhesives. A method for producing a hydrogenated petroleum resin by hydrogenating a petroleum resin will be described below.

[0027] (Method of producing hydrogenated petroleum resin) The method for producing a hydrogenated petroleum resin of the present invention comprises hydrogenating the petroleum resin obtained by the above-mentioned method for producing a petroleum resin of the present invention. There is no particular limitation on the method of hydrogenation, and any commonly known method can be used. For example, hydrogenation can be performed using a catalyst containing a metal such as nickel, palladium, cobalt, platinum, or rhodium in the presence of a diluent at a temperature of 100 to 400°C. The hydrogenated petroleum resin according to the present invention is produced by hydrogenating a high-quality petroleum resin having a narrow molecular weight distribution and a high softening point. When used as an adhesive component of a hot melt adhesive, the hydrogenated petroleum resin exhibits excellent adhesive performance, as is clear from the results of the following examples. EXAMPLES

[0028] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0029] Example 1 A raw material containing a cyclopentadiene-based component (A), a styrene-indene-based aromatic component (B), and toluene as a solvent was prepared. The composition of the raw material is shown in Table 1 below. The prepared raw material solution was passed through the loop reactor (internal volume 100 cc, inner diameter 10 mm) shown in FIG. 1 at a reactor inlet temperature of 275° C. and a loop residence time (x (min)) shown in Table 2 below. The product solution obtained via the loop reactor was then passed through the plug flow reactor shown in FIG. 2 at a reactor inlet temperature of 275° C. and a flow rate of 0.2 cc / min. The plug flow reactor used here had an inner diameter of 7 mm and a length such that the plug flow residence time (y (min)) was the value shown in Table 2 below. After the reaction in the plug flow reactor was completed, the solvent, unreacted components and low polymerized components were removed by distillation to obtain a petroleum resin (I).

[0030] <Calculation of molecular weight distribution> The weight average molecular weight (Mw) and number average molecular weight (Mn) of the petroleum resin (I) were measured, and the molecular weight distribution (Mw / Mn: weight average molecular weight (Mw) / number average molecular weight (Mn)) was calculated. The weight average molecular weight (Mw) and number average molecular weight (Mn) were measured by GPC (gel permeation chromatography) under the following conditions. Measuring equipment: HLC-8320GPC (Tosoh Corporation) Eluent: Tetrahydrofuran Column: TSKgel (Tosoh Corporation) Standard material: Polystyrene (manufactured by Tosoh) Detector: Differential refractometer (Tosoh)

[0031] <Softening point measurement> The softening point of the petroleum resin (I) was measured using a Mettler Toledo dropping point / softening point measuring system DP70 in accordance with ASTM D6090.

[0032] <Formation of insoluble matter> The petroleum resin after thermal polymerization was dissolved in cyclohexane to prepare a 50% by weight solution, which was then filtered through a stainless steel mesh with a nominal size of 80 mesh, and the weight (mg / Feed-kg) of the remaining material was measured.

[0033] The evaluation results of the properties of the petroleum resin (I) are shown in Table 2 below.

[0034] Next, 80 grams of this petroleum resin (I), 80 grams of cyclohexane as a diluent, and 2.0 grams of a nickel-based catalyst (N-113, manufactured by JGC Catalysts and Chemicals Co., Ltd.) as a catalyst were charged into a 0.2-liter autoclave, and the mixture was stirred under a hydrogen pressure of 150 kg / cm. 2 G, the hydrogenation reaction was carried out at 300°C for 1 hour. After the reaction was completed, the diluent was removed by distillation to obtain hydrogenated petroleum resin (II). The adhesive performance of the hydrogenated petroleum resin (II) was evaluated by the method described below.

[0035] <Adhesive performance> The adhesive strength was evaluated according to a method compliant with JIS Z 0237:2009. First, hydrogenated petroleum resin (II), SBS resin (Asahi Kasei Corporation's Asaprene T-438), and rubber processing oil (Japan Sun Oil's Sunpure LW-500) were mixed in a mass ratio of 25 / 60 / 15 to obtain an adhesive component. The obtained adhesive component was dissolved in toluene and applied onto a test piece made of PET film. Here, the thickness of the adhesive component after volatilizing the toluene was set to 50 micrometers. Using this test piece, a 180° peel test was performed at a tensile speed of 30 cm per minute to measure the adhesive strength. According to the obtained adhesive strength (N / mm), the adhesive performance of the hydrogenated petroleum resin (II) was determined as A to D as follows. A:10N / 10mm or more B: 8N / 10mm or more, less than 10N / 10mm C: 7N / 10mm or more, less than 8N / 10mm D: Less than 7N / 10mm

[0036] The evaluation results of the properties of the hydrogenated petroleum resin (II) are shown in Table 2 below.

[0037] <Overall rating> If the amount of insoluble matter generated exceeds 280 mg / Feed-kg, operation at a practical level becomes difficult. It is preferable to suppress the amount of insoluble matter generated to 280 mg or less, more preferably to 230 mg or less, and even more preferably to 150 mg or less. Moreover, if the adhesive performance is D in the above evaluation criteria, it is difficult to practically use it as a pressure-sensitive adhesive component. The adhesive performance is preferably C, more preferably B, and further preferably A in the above evaluation criteria. Therefore, the petroleum resin of Example 1 was comprehensively evaluated according to the following criteria. A: The amount of insoluble matter produced is 150 mg or less, and the adhesive performance is A. B: The amount of insoluble matter produced is greater than 150 mg and not more than 230 mg, and the adhesive performance is A, or the adhesive performance is B, and the amount of insoluble matter produced is not more than 150 mg. C: The amount of insoluble matter formed is more than 150 mg and 230 mg or less, and the adhesive performance is B. D: The amount of insoluble matter produced is greater than 230 mg and not more than 280 mg, and the adhesive performance is A or B, or the adhesive performance is C, and the amount of insoluble matter produced is not more than 230 mg. E: The amount of insoluble matter formed is greater than 230 mg and less than or equal to 280 mg, and the adhesive performance is C. F: The amount of insoluble matter produced is greater than 280 mg, or the adhesive performance is D.

[0038] (Examples 2 to 8) In Example 1, the loop residence time (x (min)) and the plug flow residence time (y (min)) were changed as shown in Table 2. The same procedure as in Example 1 was followed to produce a petroleum resin and a hydrogenated petroleum resin. As described in Example 1, in Examples 2 to 8, the plug flow reactor used had an inner diameter of 7 mm and a length such that the plug flow residence time (y (min)) was the value shown in Table 2. The properties of the petroleum resin and the hydrogenated petroleum resin were evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0039] (Comparative Examples 1 to 2) In Example 1, the loop residence time (x (min)) and the plug flow residence time (y (min)) were changed as shown in Table 2. The same procedure as in Example 1 was followed to produce a petroleum resin and a hydrogenated petroleum resin. As described in Example 1, also in Comparative Example 1, a plug flow reactor having an inner diameter of 7 mm and a length such that the plug flow residence time (y (min)) was the value shown in Table 2 was used. The properties of the petroleum resin and the hydrogenated petroleum resin were evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0040] (Reference examples 1~2) In Example 1, the loop residence time (x (min)) and the plug flow residence time (y (min)) were changed as shown in Table 2. The same procedure as in Example 1 was followed to produce a petroleum resin and a hydrogenated petroleum resin. As described in Example 1, also in Reference Example 1, a plug flow reactor having an inner diameter of 7 mm and a length such that the plug flow residence time (y (min)) was the value shown in Table 2 was used. The properties of the petroleum resin and the hydrogenated petroleum resin were evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0041] Example 9 In Example 1, the composition of the raw material was changed as shown in Table 1, and the loop residence time (x (min)) and plug flow residence time (y (min)) were changed as shown in Table 3. Except for this, petroleum resin and hydrogenated petroleum resin were produced in the same manner as in Example 1. As described in Example 1, in Example 9, a plug flow reactor having an inner diameter of 7 mm and a length such that the plug flow residence time (y (min)) was the value shown in Table 3 was used. The properties of the petroleum resin and the hydrogenated petroleum resin were evaluated in the same manner as in Example 1. The results are shown in Table 3.

[0042] (Comparative Examples 3 and 4) In Example 9, the loop residence time (x (min)) and the plug flow residence time (y (min)) were changed as shown in Table 3. In the same manner as in Example 9, a petroleum resin and a hydrogenated petroleum resin were produced. As described in Example 1, also in Comparative Example 3, a plug flow reactor having an inner diameter of 7 mm and a length such that the plug flow residence time (y (min)) was the value shown in Table 3 was used. The properties of the petroleum resin and the hydrogenated petroleum resin were evaluated in the same manner as in Example 9. The results are shown in Table 3.

[0043] Example 10 In Example 1, the composition of the raw material was changed as shown in Table 1, and the loop residence time (x (min)) and plug flow residence time (y (min)) were changed as shown in Table 4. Except for this, petroleum resin and hydrogenated petroleum resin were produced in the same manner as in Example 1. As described in Example 1, also in Example 10, a plug flow reactor having an inner diameter of 7 mm and a length such that the plug flow residence time (y (min)) was the value shown in Table 4 was used. The properties of the petroleum resin and the hydrogenated petroleum resin were evaluated in the same manner as in Example 1. The results are shown in Table 4.

[0044] (Comparative Examples 5 and 6) In Example 10, the loop residence time (x (min)) and the plug flow residence time (y (min)) were changed as shown in Table 4. In the same manner as in Example 10, a petroleum resin and a hydrogenated petroleum resin were produced. As described in Example 1, also in Comparative Example 5, a plug flow reactor having an inner diameter of 7 mm and a length such that the plug flow residence time (y (min)) was the value shown in Table 4 was used. The properties of the petroleum resin and the hydrogenated petroleum resin were evaluated in the same manner as in Example 10. The results are shown in Table 4.

[0045] (Reference example 3) The same raw materials as in Example 1 were prepared. The prepared raw material solution was passed through the plug flow reactor shown in FIG. 2 at a reactor inlet temperature of 275° C. and a flow rate of 0.2 cc / min. The plug flow reactor used here had an inner diameter of 7 mm and a length such that the plug flow residence time (y (min)) was the value shown in Table 5 below. The product solution obtained via the plug flow reactor was further passed through the loop reactor (internal volume 100 cc, inner diameter 10 mm) shown in FIG. 1 at a reactor inlet temperature of 275° C. and a loop residence time (x (min)) shown in Table 5 below. After the reaction in the loop reactor was completed, the solvent, unreacted components and low polymerized components were removed by distillation to obtain a petroleum resin (III). Next, the petroleum resin (III) was hydrogenated in the same manner as in Example 1 to obtain hydrogenated petroleum resin (IV). The properties of the petroleum resin (III) and the hydrogenated petroleum resin (IV) were evaluated. The results are shown in Table 5.

[0046] [Table 1]

[0047] [Table 2]

[0048] [Table 3]

[0049] [Table 4]

[0050] [Table 5] As is clear from the above examples, the petroleum resin obtained by the present invention is a petroleum resin showing good quality, with a narrow molecular weight distribution, a high softening point, and little insoluble matter. It was also found that the hydrogenated petroleum resin obtained by hydrogenating such a petroleum resin shows good adhesive performance and is a hydrogenated petroleum resin showing good quality as an adhesive component of a hot melt adhesive. In particular, it was found that petroleum resins with less insoluble matter, high adhesive performance, and a high overall rating can be obtained when the ratio (x / z) of the reaction residence time in the loop reactor (x) to the total reaction residence time (z) is within the range of 0.2 to 0.8 (see the results of Examples 3 to 6 in Table 2). Furthermore, it was found that petroleum resins with less insoluble matter and good quality can be obtained when the ratio (x / z) is within the range of 0.3 to 0.8 (see the results of Examples 4 to 6 in Table 2). The petroleum resin obtained by the present invention has a small amount of insoluble matter and little fouling, and therefore, it has been found that the method for producing a petroleum resin of the present invention is capable of continuous operation and is an economical method. [Industrial Applicability]

[0051] According to the present invention, it is possible to produce petroleum resins and hydrogenated petroleum resins that are particularly suitable for use as tackifier resins for hot melt adhesives. [Explanation of symbols]

[0052] 11 Loop Reactor 12 Introductory tube 13 Tubular reactor body 14 Pump 15 Cooler 16 Extraction tube 21 Plug Flow Reactor 22 Introductory tube 23 Tubular reactor body 24 Pump 25 Cooler 26 Extraction tube 27 Jacket 31 Tank Reactor 32 Introductory tube 33 Tank-type reactor body 34 Pump 35 Cooler 36 Extraction tube 37 Jacket 38 Mixer

Claims

1. A method for producing a petroleum resin by subjecting a raw material containing at least a cyclopentadiene-based component (A) and a styrene-indene-based aromatic component (B) to a thermal polymerization reaction, comprising: a first polymerization reaction step of thermally polymerizing the raw material using a loop reactor; a second polymerization reaction step of thermally polymerizing the polymerization reaction product obtained in the first polymerization reaction step using a plug flow reactor.

2. 2. The method for producing a petroleum resin according to claim 1, wherein the ratio (x / z) of the reaction residence time (x) of the loop reactor to the total reaction residence time (z) obtained by adding up the reaction residence time (x) of the loop reactor in the first polymerization reaction step and the reaction residence time (y) of the plug flow reactor in the second polymerization reaction step is 0.1 to 0.

9.

3. The method for producing a petroleum resin according to claim 2, wherein the ratio (x / z) of the reaction residence time (x) of the loop reactor to the total reaction residence time (z) obtained by adding up the reaction residence time (x) of the loop reactor in the first polymerization reaction step and the reaction residence time (y) of the plug flow reactor in the second polymerization reaction step is 0.2 to 0.

8.

4. The method for producing a petroleum resin according to claim 2 or 3, wherein the total reaction residence time (z) is 30 to 180 minutes.

5. The cyclopentadiene-based component (A) is contained in an amount of 50 to 90% by weight relative to the raw material, and the styrene-indene-based aromatic component (B) is contained in an amount of 10 to 50% by weight relative to the raw material. The method for producing a petroleum resin according to any one of claims 1 to 4.

6. In the styrene-indene aromatic component (B), the weight ratio (C-1 / C-2) of the styrenes (C-1) contributing to the thermal polymerization reaction to the indenes (C-2) contributing to the thermal polymerization reaction is 0.6 to 4.

0. The method for producing a petroleum resin according to any one of claims 1 to 5.

7. The method for producing a petroleum resin according to any one of claims 1 to 6, wherein the temperature during the polymerization reaction in the first polymerization reaction step and the second polymerization reaction step is 230 to 320 ° C.

8. A method for producing a hydrogenated petroleum resin, comprising a step of hydrogenating the petroleum resin obtained by the method for producing a petroleum resin according to any one of claims 1 to 7.

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