JP3558172B2 - Method for producing α-pinene resin having high softening point - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a method for producing an α-pinene resin having a high softening point.
[0002]
[Prior art]
The α-pinene resin is used as a hot melt adhesive, a tackifier for a pressure-sensitive adhesive or the like, and is usually produced by polymerizing α-pinene in the presence of a cationic polymerization catalyst. Such α-pinene is a bicyclic hydrocarbon having a double bond in the ring, and is extremely polymerized due to its steric hindrance compared to its isomer β-pinene having a double bond outside the ring. Difficult to do. In particular, α-pinene resins having a high softening point of 140 ° C. or higher are very difficult to produce due to such steric hindrance. Under such circumstances, various types of cationic polymerization catalysts used for α-pinene resins have been proposed.
[0003]
Known cationic polymerization catalysts used for the polymerization of α-pinene include, for example, aluminum chloride or a catalyst system in which aluminum chloride is combined with a trialkylsilicon halide, a dialkyltin dichloride or an alkylgermanium halide. (U.S. Pat. Nos. 3,354,132, 3,478,007, and 4,057,682). However, in the above-mentioned catalyst, the yield of α-pinene resin is extremely low and is not practical.
[0004]
It has also been proposed to use aluminum chloride and antimony chloride as cationic polymerization catalysts (JP-A-52-95793, Makromol. Chem. 193, 2311-2321 (1992)). According to these publications, it is described that an α-pinene resin can be obtained in a high yield. However, in the polymerization methods described in these publications, an α-pinene resin having a high softening point is obtained in a high yield. It is not possible.
[0005]
That is, in the polymerization method described in JP-A-52-95793, since the total amount of the catalyst used is as large as about 3% by weight of α-pinene, the degree of polymerization does not increase, and the α-pinene actually obtained is Most of the resins have a softening point of 115 ° C., and a resin having a high softening point of 140 ° C. or higher has not been obtained. The publication also states that an α-pinene resin having a high softening point can be obtained when the amount of the catalyst is 2% by weight or less of α-pinene. However, as described in the publication, in a polymerization method in which α-pinene is dropped into a mixed solution in which aluminum chloride and antimony chloride are previously charged in toluene, aluminum chloride and antimony chloride in the mixed solution gradually change over time. There is a problem that a complex is formed and the catalytic activity tends to decrease. Particularly, this tendency is remarkable when the amount of the catalyst is set to 2% by weight or less of α-pinene. Therefore, the polymerization method described in the publication cannot obtain an α-pinene resin having a high softening point in a high yield.
[0006]
Also, Makromol. Chem. In this method, α-pinene is polymerized by adding a mixed solution of α-pinene and antimony chloride dissolved in toluene to a dispersion in which aluminum chloride is previously dispersed in toluene. However, a mixed solution in which α-pinene and antimony chloride are dissolved may become cloudy with time or further precipitates may occur.The polymerization method described in this document also reduces the catalytic activity with time, so that α -The pinene resin cannot be obtained in high yield. The reason why the mixed solution becomes cloudy and precipitates is unknown, but the water contained in toluene and α-pinene reacts with antimony chloride to form antimony oxychloride, and this antimony oxychloride forms a complex with α-pinene. It seems to be because.
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide a method for producing an α-pinene resin having a high softening point of 140 ° C. or higher in a high yield in a catalyst system using aluminum chloride and antimony chloride as catalysts.
[0008]
[Means for Solving the Problems]
The present inventor has made intensive studies in view of the above circumstances to solve the above-mentioned problems. As a result, it has been found that, in a catalyst system using aluminum chloride and antimony chloride, α-pinene resin having a high softening point can be obtained in high yield by polymerizing α-pinene by the following specific method. The present invention has been completed based on such new findings.
[0009]
That is, according to the present invention, in producing α-pinene resin by polymerizing α-pinene with a catalyst system using aluminum chloride and antimony chloride in an inert solvent, first, (1) the total amount of the catalyst system used is α In a dispersion liquid (a) in which 1 part by weight of aluminum chloride is dispersed in an inert solvent within a range of 1 to 2% by weight of pinene, 0.5 to 1.5 parts by weight of antimony chloride is used as an inert solvent. After mixed solution (b) and α-pinene are separately added to polymerize α-pinene, (2) aluminum chloride and antimony chloride are further added to the reaction system to polymerize α-pinene. A method for producing an α-pinene resin having a high softening point, characterized in that, in an inert solvent, in producing a α-pinene resin by polymerizing α-pinene with a catalyst system using aluminum chloride and antimony chloride. First, (1) When the total amount of the catalyst system used is within a range of 1 to 2% by weight of α-pinene, antimony chloride is added to a dispersion (a) in which 1 part by weight of aluminum chloride is dispersed in an inert solvent. A mixed solution (b) obtained by mixing 0.5 to 1.5 parts by weight in an inert solvent and a mixed solution (c) obtained by mixing α-pinene are added immediately after the preparation to polymerize α-pinene, followed by further reaction. The present invention relates to (2) a method for producing a α-pinene resin having a high softening point, wherein (a) aluminum chloride and antimony chloride are added to polymerize α-pinene.
[0010]
In the present invention, α-pinene is used as a raw material. In the present invention, α-pinene includes various natural products (turpentine oil) containing α-pinene as a main component and containing β-pinene.
[0011]
In the present invention, aluminum chloride and antimony chloride are used as catalysts. Examples of antimony chloride include antimony trichloride and antimony pentachloride. The particle size of aluminum chloride and antimony chloride is not particularly limited. However, aluminum chloride is considered to be insoluble in an inert solvent and to reduce catalytic activity due to handling when the particle size is small. The size is preferably about 200 mesh pass. Incidentally, in the present invention, there are many impurities compared with the reagent catalyst, and a relatively low-activity catalyst which is industrially produced can be used. Even if such a catalyst is used, according to the production method of the present invention, An α-pinene resin having a high softening point can be produced in a high yield.
[0012]
The production method of the present invention comprises (1) a pre-polymerization step (hereinafter, referred to as pre-polymerization) and (2) a post-polymerization step (hereinafter, referred to as post-polymerization). A catalyst system composed of antimony is charged into the reaction system, and α-pinene is polymerized in each polymerization step.
[0013]
(1) The total amount of aluminum chloride and antimony chloride used in the prepolymerization is 0.5 to 2% by weight of the α-pinene used. Preferably it is 1 to 1.8% by weight. When the total amount of the catalyst is less than 0.5% by weight, the polymerization does not proceed sufficiently, and when it exceeds 2% by weight, the degree of polymerization is not increased and an α-pinene resin having a high softening point is obtained. Can not. The ratio of aluminum chloride to antimony chloride used is 0.5 to 1.5 in weight ratio with respect to 1 in the former. Preferably it is 0.7 to 1.2. When the proportion of antimony chloride is less than 0.5, the isomerization of the cation terminal of α-pinene in the polymerization step is insufficient, and a high molecular weight (high softening point) α-pinene resin cannot be obtained. When the ratio exceeds 1.5, particularly high yield and high softening point are not obtained, and it is only economically disadvantageous.
[0014]
Further, in the present invention, (1) an α-pinene resin is produced by polymerizing α-pinene by a specific polymerization method shown below using a catalyst system using the specific amounts of aluminum chloride and antimony chloride in the prepolymerization. . That is, first, a dispersion (a) in which aluminum chloride is dispersed in an inert solvent in advance is prepared. On the other hand, antimony chloride and α-pinene are prepared so that they do not mix with each other. Usually, antimony chloride is mixed with an inert solvent to prepare a mixed solution (b), and then charged into a container (dropping funnel). Since α-pinene is in a liquid state, it is charged as it is in a container (dropping funnel). Next, the prepared mixed solution (b) and α-pinene are separately added to the dispersion liquid (a) to initiate polymerization. Alternatively, a mixed solution (c) obtained by mixing the prepared mixed solution (b) and α-pinene into the mixed solution (a) is added immediately after the preparation of the mixed solution (c) to initiate polymerization. The term “immediately after preparation” refers to a time within about 5 minutes after the preparation of the mixed solution (c) in which the catalytic activity does not decrease.
[0015]
In the present invention, as described above, in the (1) prepolymerization, two methods can be adopted. In particular, a method in which the mixed solution (c) is added to the dispersion liquid (a) immediately after preparation to start the polymerization. preferable. This is because, in the polymerization of α-pinene, isomerization of the cation growing terminal by antimony chloride eliminates steric hindrance and promotes polymerization, so that the presence of antimony chloride near α-pinene increases the yield.
[0016]
The time for dropping the α-pinene and the mixed solution (b), or the mixed solution (c) obtained by mixing them, onto the dispersion (a) is not particularly limited, but is usually about 0.5 to 4 hours. , Preferably 1-2 hours. Further, the polymerization time after these are dropped is usually about 0.5 to 24 hours, preferably 0.5 to 2 hours.
[0017]
As described above, according to the present invention, first, in prepolymerization, aluminum chloride and antimony chloride are brought into contact with α-pinene in a constantly active state. That is, by always forming a state in which the function of the catalyst can be sufficiently exhibited in the reaction system, the catalyst activity is always maintained at a high level, and the α-pinene resin is provided in a high yield. According to such a specific polymerization method, even when an attempt is made to improve the degree of polymerization by reducing the total amount of the catalyst as in the present invention, it sufficiently functions as a highly active catalyst, so that the α- Pinene resins can also be produced in high yields.
[0018]
As the inert solvent used in the present invention, aromatic hydrocarbons such as toluene, xylene, and benzene, aliphatic hydrocarbons, aromatic or aliphatic halogenated hydrocarbons, and the like can be used. Of these, aromatic hydrocarbons, especially toluene, are preferred. The amount of the inert solvent used is usually about 50 to 200 parts by weight based on 100 parts by weight of α-pinene, and these catalysts are appropriately dispersed or dissolved in accordance with the usage ratio of aluminum chloride and antimony chloride. use. In addition, the inert solvent usually contains a trace amount (about 100 to 400 ppm) of water. However, since the trace amount of water works as a co-catalyst, the inert solvent can be used without performing a dehydration operation. it can.
[0019]
The polymerization temperature is usually from -30 to 30C, preferably from -15 to 10C. When the polymerization temperature is -30 ° C or lower, the polymerization is difficult to proceed because the activity of the catalyst is low. When the polymerization temperature is 30 ° C or higher, the activity of the catalyst becomes too high, and it is difficult to obtain an α-pinene resin in high yield.
[0020]
In the present invention, as (2) post-polymerization, after (1) pre-polymerization, aluminum chloride and antimony chloride are further added to the reaction system to polymerize unreacted α-pinene. This is because, when (1) pre-polymerization alone and (2) post-polymerization are not performed, unreacted α-pinene is large, and it is difficult to obtain an α-pinene resin having a high softening point in high yield.
[0021]
(2) The total amount of aluminum chloride and antimony chloride added to the post-polymerization is not particularly limited, but is usually 1 to 2% by weight of α-pinene used. The usage ratio is usually 0.5 to 1.5, preferably 0.7 to 1.2, with respect to the former 1 in terms of weight ratio.
[0022]
(2) The method of charging aluminum chloride and antimony chloride to be added to the post-polymerization is not particularly limited. (1) Aluminum chloride and antimony chloride may be separately charged as in the prepolymerization, or both may be charged simultaneously. Moreover, you may charge by dissolving or dispersing in an inert solvent. Among these methods, a method in which aluminum chloride is first charged into a reaction system containing an α-pinene resin, and then a solution obtained by dissolving antimony chloride in an inert solvent is preferably gradually charged. The number of times of post-polymerization is not limited to one, but may be plural times.
[0023]
The post-polymerization time after the addition of the catalyst (2) is usually 1 to 24 hours, preferably 2 to 5 hours. When a solution in which antimony chloride is dissolved in an inert solvent is dropped, the dropping time is usually about 0.5 to 4 hours, preferably 1 to 2 hours.
[0024]
Thus, the solution containing the α-pinene resin obtained through the steps of (1) prepolymerization and (2) postpolymerization is treated with water or a dilute hydrochloric acid solution to remove the catalyst, and then inert. Excluding the solvent, the α-pinene resin is obtained in a solid state. The obtained α-pinene resin has a high softening point of 140 ° C. or higher.
[0025]
【The invention's effect】
According to the production method of the present invention, since the catalyst activity does not decrease, the catalyst can be maintained at a high activity even when the amount of the catalyst is 2% or less, and the α-pinene resin having a high softening point of 140 ° C. or more is reduced to 80% or more. Can be produced in high yield. Further, according to the production method of the present invention, the α-pinene resin having a high softening point has a high yield even when an industrially produced catalyst having a relatively large amount of impurities and relatively low catalytic activity is used as compared with the reagent catalyst. Can be manufactured at a rate.
[0026]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.
[0027]
Example 1
75 g of toluene was charged into a glass kolben, the temperature in the system was cooled to −15 ° C., and 0.708 g of aluminum chloride (purity: 99.86%, manufactured by Nippon Soda Co., Ltd.) was added. Next, a device for mixing the dropping funnel (A) and the dropping funnel (B) with the dropping funnel (C) is provided in the glass kolben, and 73.5 g of α-pinene is charged into the dropping funnel (A). The funnel (B) was charged with a solution in which 0.605 g of antimony trichloride (purity: 99.92%, manufactured by Nippon Chemical Industry Co., Ltd.) was dissolved in 33.75 g of toluene. Dropping is started from each of the dropping funnel (A) and the dropping funnel (B), and a mixed solution is prepared with the dropping funnel (C). Started. Dropping was started from each of the dropping funnel (A) and the dropping funnel (B), and the whole amount was dropped into a glass corbene in about 2 hours, followed by cooling for 0.5 hour. Further, 0.708 g of aluminum chloride (purity: 99.86%, manufactured by Nippon Soda Co., Ltd.) was charged into a kolben, and antimony trichloride (purity: 99.92%, manufactured by Nippon Chemical Industry Co., Ltd.) was added to 33.75 g of toluene. A solution in which 605 g was dissolved was added dropwise over 1 hour to carry out post-polymerization. Thereafter, it was kept cool for 0.5 hour. The post-polymerization operation was performed once more. After the post-polymerization, 10% by weight of dilute hydrochloric acid was added to a glass kolben to remove the activity of the catalyst. Further, the resultant was washed with a toluene layer three times with 10% by weight of dilute hydrochloric acid and neutralized with a 7% by weight aqueous solution of sodium hydrogen carbonate. Next, the toluene layer and the aqueous layer were separated, the catalyst was filtered, and then heated to 110 to 150 ° C. to remove toluene and unreacted α-pinene. Furthermore, reduced pressure residence was performed at 200 ° C. and a degree of vacuum of 10 mmHg for about 0.5 to 1 hour. This was allowed to cool to room temperature to obtain 69.6 g of an α-pinene resin having a softening point of 144.9 ° C (yield 94.8%).
[0028]
Example 2
In Example 1, the same operation as in Example 1 was performed, except that the dropping funnel (A) and the dropping funnel (B) were separately dropped onto the glass corben without providing the dropping funnel (C) on the glass corben. 66.2 g of α-pinene resin having a softening point of 144.2 ° C. was obtained (yield: 90.1%).
[0029]
Example 3
In Example 1, the same operation as in Example 1 was performed except that the amount of aluminum chloride used in the post-polymerization was 0.354 g, the amount of antimony chloride was 0.303 g, and the post-polymerization was performed only once. Then, 59.9 g of α-pinene resin having a softening point of 173 ° C. was obtained (yield: 81.5%).
[0030]
Comparative Example 1
108.75 g of toluene was charged into a glass kolben, and the temperature in the system was cooled to -15 ° C. After cooling, 0.708 g of aluminum chloride (purity 99.99%, manufactured by Aldrich) and 0.605 g of antimony trichloride (purity 99.999%, manufactured by Aldrich) were added to prepare a mixed solution. Next, 73.5 g of α-pinene was charged into the dropping funnel, and the whole amount was dropped into a glass kolben in about 2 hours. Then, after keeping it cool for 2 hours, 10% by weight of dilute hydrochloric acid was added to a glass kolben to perform a treatment for eliminating the activity of the catalyst. Further, the resultant was washed with a toluene layer three times with 10% by weight of dilute hydrochloric acid and neutralized with a 7% by weight aqueous solution of sodium hydrogen carbonate. Next, the toluene layer and the aqueous layer were separated, the catalyst was filtered, and then heated to 110 to 150 ° C. to remove toluene and unreacted α-pinene. Furthermore, reduced pressure residence was performed at 200 ° C. and a degree of vacuum of 10 mmHg for about 0.5 to 1 hour. This was allowed to cool to room temperature to obtain 23.2 g of α-pinene resin having a softening point of 131.2 ° C (yield 31.6%).
[0031]
Comparative Example 2
75 g of toluene was charged into a glass kolben, and the temperature in the system was cooled to -15 ° C. After cooling, 0.708 g of aluminum chloride (purity 99.99%, manufactured by Aldrich) was added to prepare a mixed solution. Next, a solution prepared by dissolving 73.5 g of α-pinene and 0.605 g of antimony chloride (purity 99.999%, manufactured by Aldrich) in 33.75 g of toluene was charged into the dropping funnel. The whole amount was dropped from the dropping funnel into a glass kolben in about 2 hours. Then, after keeping it cool for 2 hours, 10% by weight of dilute hydrochloric acid was added to a glass kolben to perform a treatment for eliminating the activity of the catalyst. Further, it was washed about three times with a toluene layer with 10% by weight of dilute hydrochloric acid, and neutralized with a 7% by weight aqueous solution of sodium hydrogen carbonate. Next, the toluene layer and the aqueous layer were separated, the catalyst was filtered, and then heated to 110 to 150 ° C. to remove toluene and unreacted α-pinene. Further, vacuum distillation was performed at 200 ° C. and a degree of vacuum of 10 mmHg for about 0.5 to 1 hour. This was allowed to cool to room temperature to obtain 12.5 g of an α-pinene resin having a softening point of 125 ° C (yield 17.0%).

Claims (3)

In producing α-pinene resin by polymerizing α-pinene with a catalyst system using aluminum chloride and antimony chloride in an inert solvent, first, (1) the total amount of the catalyst system is from 1 to α-pinene. Within a range of 2% by weight, a mixed solution obtained by mixing 0.5 to 1.5 parts by weight of antimony chloride with an inert solvent in a dispersion (a) in which 1 part by weight of aluminum chloride is dispersed in an inert solvent ( b) and α-pinene are added separately to polymerize α-pinene, and then (2) aluminum chloride and antimony chloride are added to the reaction system to polymerize α-pinene. A method for producing an α-pinene resin having a high softening point. In producing α-pinene resin by polymerizing α-pinene with a catalyst system using aluminum chloride and antimony chloride in an inert solvent, first, (1) the total amount of the catalyst system is from 1 to α-pinene. Within a range of 2% by weight, a mixed solution obtained by mixing 0.5 to 1.5 parts by weight of antimony chloride with an inert solvent in a dispersion (a) in which 1 part by weight of aluminum chloride is dispersed in an inert solvent ( A mixed solution (c) obtained by mixing b) and α-pinene is added immediately after preparation to polymerize α-pinene, and then (2) aluminum chloride and antimony chloride are added to the reaction system to form α-pinene. And a method for producing an α-pinene resin having a high softening point. (2) The total amount of aluminum chloride and antimony chloride to be added is 1 to 2% by weight of α-pinene, and the ratio of use is 0.5 to 1.5 with respect to 1 for the former and 1 for the latter. Item 3. The method according to Item 1 or 2 .