JPH02289603A - Continuous production of hydrogenated hydrocarbon resin - Google Patents

Abstract

PURPOSE:To produce the subject resin having good color tone and thermal stability and useful as adhesives, etc., by continuously polymerizing a cyclopentadienic monomer or a mixture thereof with a comonomer, continuously removing the un-reacted monomers and low mol.wt. polymers from the polymerization product and subsequently hydrogenating the remained polymer in a flow type fixed bed reactor. CONSTITUTION:A monomer mixture comprising 100-50wt.% of a cyclohexadienic monomer (e.g. cyclopentadiene) and 0-40wt.% of a comonomer (e.g. isoprene) copolymerizable therewith is continuously polymerized in the absence of an inactive solvent, and the unreacted monomers and low mol.wt. oily polymers are continuously removed. The prepared hydrocarbon resin is introduced into a flow type fixed bed reactor in the melted state and continuously hydrogenated to provide the objective hydrogenated hydrocarbon resin continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a hydrogenated hydrocarbon resin, and more particularly, the present invention relates to a method for producing a hydrogenated hydrocarbon resin, and more particularly, it relates to a method for producing a hydrogenated hydrocarbon resin. The present invention relates to a method for continuously producing a hydride of a hydrocarbon resin obtained by polymerization.

[Conventional technology]

Hydrogenated hydrocarbon resins have excellent hue and thermal stability, so they are used in adhesives based on conjugated diene elastomers, adhesives and adhesives based on styrenic block copolymers, It is used as a tackifier in adhesives based on polyolefin polymers, and is particularly prized as a tackifier in hot-melt compositions produced by heating cross-fertilization.

Hydrogenated hydrocarbon resins include hydrocarbon resins obtained by polymerizing thermal decomposition products of petroleum naphtha in the presence of Friedel-Crafts catalysts, and hydrocarbon resins obtained by thermally polymerizing monomer mixtures containing cyclopentadiene monomers as the main component. It is produced by hydrogenating the hydrocarbon resin obtained by Conventionally, as the hydrogenation method, a batch suspension bed system or a flow suspension bubble column system using a hydrogenation catalyst such as powdered nickel or platinum has been generally adopted. According to these methods,
After the hydrogenation reaction is completed, a filtration step is essential to separate the hydrogenated hydrocarbon resin and the powdered catalyst. However, since it is difficult to filter the resin in its molten state, the catalyst is often filtered after first diluting it with an organic solvent such as xylene or toluene to reduce the viscosity of the hydrogenation reaction product. Alternatively, the raw material hydrocarbon resin may be dissolved in a saturated hydrocarbon solvent such as cyclohexane or decalin from the beginning and hydrogenated in solution form. Either method requires a step of distilling off the solvent from the filtrate after filtering the catalyst.

Furthermore, handling of the raw material resin complicates the hydrogenation process. In the process of heating and melting the raw resin or dissolving it in a solvent, it is inevitable that some oxygen will be entrained. must be removed. Even if this operation is carried out sufficiently after the melting or dissolution of the resin is completed, especially when heating and melting the raw resin, the thermal stability of the raw resin itself is insufficient. Some degree of deterioration is inevitable. In addition, if the raw material resin is stored for a long time after it is produced before it is hydrogenated, or if it is stored at a relatively high temperature, peroxides may form in the resin and have a negative effect on the hydrogenation reaction. It becomes difficult to obtain hydrogenated hydrocarbon resins with the desired stability. Therefore, the raw material resin must be strictly controlled before being subjected to hydrogenation.

In view of the problems with the conventional hydrogenated hydrocarbon resin manufacturing method, from the viewpoint of resource saving, energy saving, and size saving,
Establishment of a rational hydrocarbon resin hydrogenation process has been eagerly desired.

[Problems to be Solved by the Invention] An object of the present invention is to provide a method for producing a hydrogenated hydrocarbon resin through an integrated continuous process from the polymerization step to the hydrogenation step.

Another object of the present invention is to hydrogenate hydrocarbon resin without repeating cooling and heating, without requiring resin filtration or solvent removal steps, and without deterioration of the resin. The object of the present invention is to provide a method for producing a synthetic resin.

The inventors of the present invention have conducted intensive studies to solve the above-mentioned drawbacks of conventional hydrogenated hydrocarbon resin production methods. By directly linking the removal process of oily polymers and the continuous hydrogenation process of hydrocarbon resin, it is possible to omit the catalyst filtration process without using organic solvents, and to achieve stable quality hydrocarbonization. The present invention was completed by discovering that hydrogen resin can be obtained.

[Means for Solving the Problems] Thus, according to the present invention, 100 to 50% by weight of a cyclopentadiene monomer and 0 to 50% by weight of a comonomer copolymerizable therewith.
After continuous thermal polymerization of a monomer mixture consisting of 50% by weight in the substantial absence of an inert solvent and subsequent continuous removal of unreacted monomers and low molecular weight oily polymers, the Provided is a method for continuously producing a hydrogenated hydrocarbon resin, which comprises introducing the hydrocarbon resin in a molten state into a flow-type fixed bed reactor and continuously hydrogenating the resin.

Next, the constituent elements of the present invention will be explained in detail.

(Monomer component) In the present invention, a monomer mixture containing a cyclopentadiene monomer as a main component is used. In addition to cyclopentadiene, cyclopentadiene monomers include lower alkyl-substituted cyclopentadiene such as methylcyclopentadiene and ethylcyclopentadiene, and lower Diels-substituted cyclopentadiene such as dimers, trimers, and codimers thereof. Alder adducts are included.

Comonomers that can be copolymerized with cyclopentadiene monomers include ethylene, propylene, butene, pentene, hexene, methylbutene, cyclopentene, styrene, α
- Monoolefins such as methylstyrene; diolefins such as butadiene, isobrene, pentadiene; fatty acid esters of unsaturated alcohols such as vinyl acetate, vinyl propynate; methyl acrylate, ethyl acrylate, butyl acrylate, diacrylic acid - Alkyl esters of α,β monounsaturated carboxylic acids such as ethylhexyl and methyl methacrylate; unsaturated alcohols such as allyl alcohol and crotyl alcohol; and the like.

The softening point, average molecular weight, molecular weight distribution, and compatibility with various high molecular weight polymers of the hydrocarbon resin produced vary depending on the type of comonomer and monomer mixture composition, so depending on the intended use of the resin. These comonomers are selected as appropriate, but if the proportion of the comonomer component in the monomer mixture exceeds 50% by weight, the yield of the resin will drop significantly, so it is not preferred. .

(Thermal polymerization step) Thermal polymerization is performed by heating the monomer mixture at 200 to 300°C, preferably 230 to 280°C, in the substantial absence of an inert solvent.
. . into one or more reactors equipped with stirring blades and maintained at . This is achieved by flowing with an average residence time of 0.5 to 20 hours.

Substantially no inert solvent means that some amount of inert solvent may be present as long as the monomer concentration exceeds 95% by weight.

However, if an inert solvent is used, a recovery process is required and the polymerization rate tends to be suppressed.
It is preferable not to use any inert solvent.

(Step for removing unreacted monomers, etc.) In the method of the present invention, a step for removing unreacted monomers, etc. is provided consecutively to the thermal polymerization step.

Unreacted monomers and low molecular weight oily polymers contained in the polymerization reaction solution are removed following the thermal polymerization step. If a small amount of inert solvent is present in the reaction system, the inert solvent is also removed in this step.

Removal of unreacted monomers etc. can be carried out continuously by vacuum distillation or steam distillation. Examples of the evaporator used for this purpose include a stirring tank equipped with equipment for heating and pressure reduction, a thin film evaporator equipped with rotary blades, and the like.

Further, the step of removing easily volatile components such as unreacted monomers and the step of removing the oily polymer may be performed successively in a stepwise manner. For example, a vacuum distillation process may be carried out in two stages, or the polymer solution may be flashed at high temperatures, usually between 150 and 250°C, to first remove easily volatile components, and then the oily polymer may be removed in a thin film evaporator. May be removed.

The operating conditions for vacuum distillation or thin film evaporators are usually 18
50mmHg or less at 0-280℃, preferably 20mm
Hg or less.

(Hydrogenation Reaction Step) In the present invention, a hydrogenation reaction is carried out consecutively to the step of removing unreacted monomers and the like. That is, after the removal step, the hydrocarbon resin is once taken out and is not reheated or dissolved in a solvent during hydrogenation.

In the hydrogenation reaction, the obtained hydrocarbon resin is introduced in a molten state into a flow-through type fixed bed reactor and continuously hydrogenated. A flowing fixed bed reactor is a reactor filled with a fixed bed catalyst supporting metals such as nickel or platinum, in which resin and hydrogen gas are passed through the top or bottom of the reactor.
This is a reactor designed to carry out hydrogenation reactions continuously.

The metal species of the hydrogenation catalyst used in the present invention are nickel,
Known materials such as platinum, palladium, rhodium, etc. are not particularly limited. The carrier for the catalyst is also not particularly limited, but alumina, silica, carbon, titania, etc., which are porous and have a large specific surface area, are preferable. These hydrogenation catalysts and supports can be used in any combination, but
Among these, it is particularly preferable to use a catalyst in which nickel is supported on alumina, since it is possible to obtain a hydrogenated hydrocarbon resin with an extremely excellent hue.

Catalysts in which the above-mentioned metals are supported on these carrier powders are molded into pellets by a method such as tableting or extrusion, and catalysts in which the above-mentioned metals are supported on the surface of carriers that have been previously formed into cylindrical, pellet-like, or spherical shapes. A catalyst that has been prepared is used. In addition, the size of the catalyst is 0.3 to 10 mm in diameter, preferably 0.6 to 5 m, taking into account its effective area and pressure loss within the reactor.
A spherical shape of m or a size equivalent to this is preferable.

The method of flowing hydrocarbon resin and hydrogen gas to the fixed bed catalyst packed bed is not particularly limited, but if hydrogen gas is introduced from the bottom of the packed bed (lower part of the reactor), the packed catalyst will be unavoidably shaken, and the catalyst will be damaged. Since there is a risk that the hydrocarbon resin and hydrogen gas may gradually fall off and be discharged together with the hydrogenated resin, a so-called downward cocurrent flow system in which both the hydrocarbon resin and hydrogen gas are passed downward from the upper part of the filling M (the upper part of the reactor) is preferable.

Regarding hydrogenation reaction conditions, hydrogenation reaction rate, reaction time,
Although it is determined as appropriate considering the reactor specifications, etc., the reaction pressure is usually 20 to 200 kg/crtr, preferably 5
0 to 150 kg/crr? Good. The hydrogen supply amount is 1.0 to 10 of the theoretical hydrogen absorption amount of the raw resin.
The hydrogenation reaction can be sufficiently completed by supplying hydrogen gas that slightly exceeds the theoretical hydrogen absorption amount, preferably 1.2 to 3 times. The reaction temperature is 150~
The reaction temperature is 300°C, preferably 180 to 270°C, and the reaction can be completed more efficiently at a higher temperature, but the reaction temperature is preferably selected within this range in order to suppress deterioration of the catalyst due to sintering. The supply amount of hydrocarbon resin is
W H S V (Weight Hourly S
paceVelocity, resin supply amount per hour/
catalyst loading amount). 0.02-10, preferably 0.05
It is better to set it to ~2.

[Effects of the Invention] According to the method of the present invention, a hydrogenated hydrocarbon resin can be produced in an integrated and continuous process from the polymerization process to the product delivery process, and there is no need to repeat heating and cooling of the resin.

Furthermore, the steps of filtration of the hydrogenation catalyst and removal of the solvent can be omitted. Furthermore, there is no fear that the raw material hydrocarbon resin will deteriorate before it is hydrogenated, and a hydrogenated hydrocarbon resin of stable quality can be obtained.

(Margin below) [Examples] The present invention will be described in more detail below with reference to Examples, Comparative Examples, and Reference Examples, but the present invention is not limited only to these Examples. Note that parts and percentages in Examples, Comparative Examples, and Reference Examples are based on weight unless otherwise specified.

[Example 1] An autoclave equipped with a stirrer was heated at a temperature of 260°C and a pressure of 1
0kg/crt? G and dicyclopentadiene 7
A monomer mixture consisting of 0% isobrene and 30% isobrene was circulated for an average residence time of 4 hours to carry out a thermal polymerization reaction.

The polymerization reaction product was successively led to a second and third similar autoclave. Each autoclave is 210
The liquid level in the autoclave was set such that the temperature was maintained at .degree. C. and the average residence time of the reaction products was 2 hours in total. The gas phases of the second and third autoclaves were each led to a vacuum bomb via a trap, and unreacted monomers and low molecular weight oily polymers in the reaction product were continuously removed.

The reduced pressure conditions were 50 mmHg in the second autoclave;
In the third autoclave it was lommHg.

The hydrocarbon resin retained in the third autoclave was introduced into a flow type fixed bed reactor filled with a hydrogenation catalyst, and a hydrogenation reaction was continuously carried out to obtain a hydrogenated hydrocarbon resin.

As the hydrogenation catalyst, a catalyst (manufactured by JGC Chemical Co., Ltd.) in which stabilized nickel was supported on the surface of alumina pellets having a diameter of 3 mm and a height of 3 mm was used. Inside the reactor, the temperature is 235-245°C and the pressure is 100 kg/c.
rr? and the flow rate of the resin is such that the WHSV is 0.14.
hr-', the hydrogen gas flow rate was set to be 1.5 times the theoretical hydrogen absorption amount of the resin, and both the resin and hydrogen gas were allowed to flow downward from the top of the reactor.

The softening points of the obtained hydrogenated hydrocarbon resin and the hydrocarbon resin before the hydrogenation reaction were measured according to the ring and ball method specified in JIS K-2531, and the hue was determined according to JIS K-540.
The bromine number was measured by the Gardner chromaticity defined as 0, and the bromine number was measured by the titration method defined in JIS K-2543.

The results are shown in Table 1.

Table 1 [Example 2] Hydrogen was prepared in the same manner as in Example 1, except that a monomer mixture consisting of 70% dicyclopentadiene and 30% 2-methyl-2-butene was thermally polymerized and then hydrogenated. A carbonized hydrocarbon resin was obtained. The results of measuring the softening point, hue, and bromine number are shown in Table 2 together with the measurement results for the raw resin.

From the results shown in Table 2 and Table 1, it can be seen that the hydrogenated hydrocarbon resin obtained by the present invention is almost completely hydrogenated with a hydrogenation rate of 98.3% and exhibits an excellent hue.

Note that the hydrogenation rate is a value determined from the following formula.

Bromine number of raw resin The hydrogenated hydrocarbon resin obtained by the production method of the present invention is
The hydrogenation rate determined from the bromine number in Table 2 was 98.0%, and an excellent hue was exhibited.

(Left below) [Reference Example 1] Instead of continuously removing unreacted monomers and low molecular weight oily polymers from the polymerization reaction product obtained in the same manner as in Example 1, batch vacuum distillation was carried out. After these were removed and the hydrocarbon resin was once recovered, it was heated and melted at 180°C and continuously hydrogenated under the same hydrogenation reaction conditions as in Example 1.

The measurement results of the softening point, bromine number, and hue of the obtained hydrogenated resin are shown in Table 3 together with the measurement results of the raw material resin.

Table 3 [Example 3, Comparative Example 1] 30 g each of the hydrogenated hydrocarbon resins obtained in Example 1 and Reference Example 1 were placed in a 50 cc glass beaker and heated at 180°C.
After leaving it in a controlled oven for 6 hours,
It was dissolved in toluene to a solid concentration of 50%, and its Gardner chromaticity was measured. Table 4 shows the measurement results for the initial values and values after heat treatment.

Table 4 From these results, it is clear that when a hydrogenated hydrocarbon resin is produced in a continuous process from thermal polymerization to hydrogenation using the production method of the present invention, the obtained hydrogenated hydrocarbon resin has an excellent hue even after heat treatment. It can be seen that thermal deterioration does not progress. On the other hand, once the hydrocarbon resin is recovered,
When heated and melted and continuously hydrogenated (Reference Example 1),
The obtained hydrogenated hydrocarbon resin has a deteriorated hue after heating and is inferior in heat resistance.

Claims (1)

[Claims] (1) Cyclopentadiene monomer 100-50% by weight
A monomer mixture consisting of 0 to 50% by weight of a comonomer copolymerizable with this is continuously thermally polymerized in the substantial absence of an inert solvent, and then unreacted monomers and low molecular weight A continuous production of hydrogenated hydrocarbon resin, characterized in that after the oily polymer is continuously removed, the obtained hydrocarbon resin is introduced in a molten state into a flow-through type fixed bed reactor for continuous hydrogenation. manufacturing method.