JP2007211240A - Acrylic-modified polybutadiene - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acrylic-modified polybutadiene being improved in environmental safety, exhibiting an extremely high physical properties of a cured product formed by thermal curing, an ultraviolet ray or an electron beam, and exhibiting a precisely controlled curing reaction, and a production method of the acrylic-modified polybutadiene. <P>SOLUTION: There are provided the acrylic-modified polybutadiene in which (meth)acrylic acid forms an ester bond directly at at least one end of a polymer chain where 80% or more of butadiene units constituting the polymer chain has a 1,2-bond, and the production method of the acrylic-modified polybutadiene in which meth(acrylate) is reacted with a hydroxyl group-containing polybutadiene having a hydroxyl group at at least one end of the polymer chain where 80% or more of butadiene units comprising the polymer chain has 1,2-bond under the presence of a catalyst. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to acrylic-modified polybutadiene, and more particularly to acrylic-modified polybutadiene produced by a safe method.

  Conventionally, polymers having a functional group such as a hydroxyl group or a carboxyl group bonded to an end portion of a polymer chain, which are useful as an electrodeposition coating material, a paint, a casting resin, a molding resin, an adhesive, and the like are known. For example, liquid polybutadiene is a resin that exhibits excellent water and moisture resistance, chemical resistance, electrical properties (high dielectric strength, low dielectric constant, arc resistance), transparency, and high toughness by curing. Become.

  Examples of the polymer curing method include a thermal curing method using an organic peroxide as a catalyst, and a curing method using an ultraviolet ray and an electron beam. Although a cured resin having a high crosslinking density can be obtained by the thermosetting method, it is difficult to precisely control the curing. On the other hand, in the curing method using ultraviolet rays / electron beams, although precise control of curing is easy, it is often difficult to obtain a cured resin having a sufficient crosslinking density.

  Therefore, in order to enhance curability by heat, ultraviolet rays or electron beams, a polymer in which the functional group of a polymer having a functional group such as a hydroxyl group is modified with a polymerizable functional group such as an acryloyl group or a methacryloyl group (hereinafter referred to as “polymer”). ("Meth) acrylate") has been proposed (see Patent Documents 1 to 7). This polymer (meth) acrylate has enhanced cured properties of ultraviolet rays or electron beams, and can control the curing reaction more precisely. For example, it can be used as an adhesive for precision machines or optical instruments. it can.

  As the polymer (meth) acrylate, the following liquid polybutadiene acrylate (D) (hereinafter referred to as compound (D)) is known. For example, compound (A) having an isocyanate group (hereinafter referred to as compound (A) ), Acrylate (B), and 1,2-liquid polybutadiene (C) having a hydroxyl group at the molecular end are heated to a predetermined temperature in a solvent-free or inert solvent to obtain a simple and high yield. (See the following reaction formula.)

  The compound (D) thus obtained forms a coating film of the composition containing the compound (D) or the compound (D) on the surface of the article, and not only heat curing but also ultraviolet rays or electron beams at the cured site. It can be cured by irradiation.

JP-A-48-89296 JP-A-48-37495 JP 49-10991 A JP-A-49-23298 Japanese Patent Laid-Open No. 63-23973 JP-A 63-220240 JP 2002-371101 A

  However, the above polymer (meth) acrylate uses toluene diisocyanate (compound (A)) as a raw material, and such toluene diisocyanate is a sensitizing substance and is considered to be carcinogenic. Therefore, it is desired to improve the environmental safety including the working environment.

  An object of the present invention is to provide an acrylic-modified polybutadiene that improves environmental safety, has extremely high cured properties by heat curing, ultraviolet rays, and electron beams, and can precisely control the curing reaction, and a method for producing the same. There is to do.

  As a result of diligent research to solve the above problems, the inventors of the present invention directly, at the end of a linear polymer chain in which 80% or more of the butadiene units constituting the polymer chain are composed of 1,2 bonds, It has been found that the above problem can be solved by ester-linking (meth) acrylic acid, and the present invention has been completed.

  That is, according to the present invention, (1) (meth) acrylic acid is directly ester-bonded to at least one end of a polymer chain in which 80% or more of butadiene units constituting the polymer chain are composed of 1,2 bonds. (2) Acrylic modified polybutadiene as described in (1), wherein (meth) acrylic acid is ester-bonded directly to both ends of the polymer chain, and (3) ) The number average molecular weight is 500 to 10,000. The present invention relates to the acrylic-modified polybutadiene described in (1) or (2).

  Further, the present invention provides (4) a hydroxyl group-containing polybutadiene in which 80% or more of the butadiene units constituting the polymer chain have a hydroxyl group at least at one end of the polymer chain in the presence of a catalyst. A process for producing an acrylic-modified polybutadiene characterized by reacting a (meth) acrylic acid ester, or (5) a hydroxyl group-containing polybutadiene has hydroxyl groups at both ends. A method for producing modified polybutadiene, (6) the method for producing acrylic modified polybutadiene according to (4) or (5), wherein the catalyst is tetraalkoxytitanium, and (7) the catalyst is a dialkyltin dicarboxylic acid The method for producing an acrylic-modified polybutadiene according to (4) or (5), which is a salt or a dialkyltin oxide. To.

  The acrylic-modified polybutadiene of the present invention is improved in environmental safety by changing the production method, and has not only thermal curing but also extremely high cured physical properties by ultraviolet rays and electron beams, so that the curing reaction can be precisely controlled. And since it is low-viscosity, it is very excellent in handling property. Furthermore, according to the method for producing the acrylic modified polybutadiene of the present invention, the acrylic modified polybutadiene of the present invention can be easily produced.

  As the acrylic-modified polybutadiene of the present invention, (meth) acrylic acid is directly ester-bonded to at least one end of a polymer chain in which 80% or more of the butadiene units constituting the polymer chain are composed of 1,2 bonds. If it is, it will not restrict | limit in particular, The acrylic modified polybutadiene of this invention can be used as a coating material, casting resin, molding resin, an adhesive agent, etc. In addition to improving environmental safety by changing the manufacturing method, not only thermal curing but also curing properties by ultraviolet rays and electron beams are extremely high, and the curing reaction can be precisely controlled. It can be suitably used for adhesives and paints for articles having a precise and fine structure. In the present invention, (meth) acrylic acid means acrylic acid and methacrylic acid.

  As described above, the polymer chain in the acrylic-modified polybutadiene of the present invention is a linear chain in which 80% or more of the butadiene units constituting the polymer chain are composed of 1,2 bonds, and the curing reaction is made more precise. In terms of controllability, 85% or more of the butadiene units are preferably composed of 1,2 bonds, more preferably 90% or more of the butadiene units are composed of 1,2 bonds, and 95% or more of the butadiene units are 95% or more. More preferably, it consists of 1,2 bonds.

  The other end of the acrylic-modified polybutadiene of the present invention may be unsubstituted (hydrogen atom) or may have a substituent. Examples of the substituent include a hydroxyl group, a carboxyl group, (meta ) Acrylic acid ester group and the like can be mentioned, and a (meth) acrylic acid ester group is preferable. Thereby, the cured physical properties are further improved while the viscosity is low, and the curing reaction can be controlled more precisely.

  That is, the structure shown below in which (meth) acrylic acid is ester-bonded directly to both ends of the polymer chain is preferable. In addition, the polymer chain portion of butadiene shown below may be one in which 80% or more is composed of 1,2 bonds. Alternatively, acrylic acid may be directly ester-bonded to one end and methacrylic acid may be directly ester-bonded to the other end.

  In addition, the number average molecular weight of the acrylic-modified polybutadiene of the present invention is usually about 500 to 10,000, and preferably 1,000 to 5,000.

  Such an acrylic-modified polybutadiene of the present invention has a catalyst in a hydroxyl group-containing polybutadiene in which 80% or more of the butadiene units constituting the polymer chain have a hydroxyl group at least at one end of the polymer chain. Below, it can manufacture by making (meth) acrylic acid ester react. The amount of (meth) acrylic acid ester added is generally unrecognizable depending on its type, but is usually preferably 9 to 200% by weight, and preferably 14 to 100% by weight, based on the hydroxyl group-containing polybutadiene. Is more preferable. Thereby, (meth) acrylic acid can be introduced into the terminal at a ratio of 50% or more, preferably 70% or more, more preferably 90% or more, and still more preferably 95% with respect to the terminal hydroxyl group.

  Further, the hydroxyl group-containing polybutadiene used in the production method of the present invention preferably has a hydroxyl group at at least one end and preferably has a hydroxyl group at both ends, whereby (meth) acrylic acid is directly attached to both ends. Ester-linked acrylic modified polybutadiene can be produced. Examples of the (meth) acrylic acid ester to be reacted with the hydroxyl group-containing polybutadiene include methyl (meth) acrylate and ethyl (meth) acrylate.

As a method for producing a hydroxyl group-containing polybutadiene in the production method of the present invention, for example, polybutadiene is prepared by polymerizing butadiene in a solution in the presence of a sodium catalyst, and an epoxy compound such as ethylene oxide or propylene oxide is added thereto. The method of doing is mentioned. Thereby, a hydroxyl group can be introduced into the terminal of polybutadiene at a ratio of 80% or more, preferably 90% or more. Specific examples of such a hydroxyl group-containing polybutadiene include trade name: G-2000 manufactured by Nippon Soda Co., Ltd. This hydroxyl group-containing polybutadiene is a non-hydrogenated product that has not been subjected to hydrogenation treatment.

  The reaction between the hydroxyl group-containing polybutadiene and the (meth) acrylic acid ester can be carried out in the absence of a solvent or in a suitable inert solvent in the presence of a suitable catalyst. Examples of such catalysts include organic titanium compounds containing tetraalkoxytitanium such as tetramethoxytitanium, tetraethoxytitanium, tetrapropoxytitanium and tetrabutoxytitanium, dialkyltin dicarboxylates such as dibutyltin dilaurate and dioctyltin dilaurate, dibutyltin oxide, An organic tin compound containing a dialkyltin oxide such as dioctyltin oxide can be used. The amount of the catalyst used is preferably 0.01 to 10 mol%, more preferably 0.1 to 3.5 mol%, based on the hydroxyl group of the hydroxyl group-containing polybutadiene. By using in this range, the acrylic modified polybutadiene of the present invention can be produced efficiently.

  In addition, the reaction between the hydroxyl group-containing polybutadiene and the (meth) acrylic acid ester is biased by removing (distilling off) the by-product alcohol such as methanol and the target product acrylic-modified polybutadiene from the reaction system. It is preferable to promote the reaction.

  The solvent used in the reaction is not particularly limited as long as it is an inert solvent for the reaction. For example, aromatic hydrocarbons such as benzene, toluene and xylene; diethyl ether, tetrahydrofuran, 1,2-dimethoxyethane, Examples include ether solvents such as 1,4-dioxane; nitrile solvents such as acetonitrile and benzonitrile; dimethyl sulfoxide and the like. Among these, aromatic hydrocarbons such as benzene, toluene and xylene are preferable.

  As reaction temperature, it is 0-130 degreeC normally, and it is preferable that it is the range of room temperature-120 degreeC. The reaction is usually completed in a few minutes to a few hours. After the completion of the reaction, the unreacted (meth) acrylic acid ester and the solvent are removed from the reaction solution, whereby the acrylic-modified polybutadiene (a liquid mainly composed of the present invention) of the present invention can be obtained.

  Since the acrylic-modified polybutadiene obtained by the production method of the present invention is a transparent liquid without white turbidity, it is also useful as an adhesive or paint for articles that require transparency such as optical instruments. The acrylic-modified polybutadiene of the present invention can be used by mixing with the hydroxyl group-containing polybutadiene or polybutadiene having no hydroxyl group.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, the technical scope of this invention is not limited to these illustrations.

[Example 1]

150.0 g of liquid polybutadiene (trade name: G-2000 Nippon Soda Co., Ltd. number average molecular weight = 1,100, (1)) in which butadiene is polymerized with 1,2-bonds in a 300 ml glass reaction vessel , 6-di-t-butyl-4-methylphenol (BHT) 0.15 g and tetrabutoxytitanium 1.6 g (2) were charged, and 30.0 g of methyl methacrylate (3) was added to 50.0 g of toluene while stirring. The reaction was carried out by adding a methyl methacrylate solution dissolved in. Subsequently, it hold | maintained at 120 degreeC in dry air for 5 hours, and distilled methanol, methyl methacrylate (3), and a solvent byproduced. Furthermore, it distilled under reduced pressure at 120 degreeC for 1 hour, and obtained 158.2g of transparent liquids. ^{In 1} H-NMR measurement (manufactured by JEOL Ltd., ECP-500), the spectrum of methylene protons to which a hydroxyl group in the vicinity of 3.6 ppm was bonded was shifted to about 4.1 ppm by transesterification. Further, even in FT-IR measurement (Perkin Elmer, Spectrum One), the absorption of hydroxyl groups in the vicinity of 3300 cm ⁻² has disappeared, and the obtained liquid contains the above acrylic-modified polybutadiene (4) as a main component. It was.

[Example 2]
150.0 g of liquid polybutadiene (trade name: G-2000 Nippon Soda Co., Ltd. number average molecular weight = 1,100, (1)) in which butadiene is polymerized with 1,2-bonds in a 300 ml glass reaction vessel , 6-di-t-butyl-4-methylphenol (BHT) 0.15 g and di-n-butyltin dilaurate 2.6 g, and 30.0 g of methyl methacrylate (3) into 50.0 g of toluene while stirring. The dissolved methyl methacrylate solution was added to carry out the reaction. Subsequently, it hold | maintained at 120 degreeC in dry air for 3 hours, methanol, methyl methacrylate (3) byproduced, and the solvent were distilled off, and 194.3g of semi-reaction liquid was obtained. Using 160.0 g of this reaction solution, the solution was further distilled off under reduced pressure at 120 ° C. for 2 hours to obtain 99.4 g of a transparent liquid. ^{In 1} H-NMR measurement (manufactured by JEOL Ltd., ECP-500), the spectrum of methylene protons to which a hydroxyl group in the vicinity of 3.6 ppm was bonded was shifted to about 4.1 ppm by transesterification. Further, even in FT-IR measurement (Perkin Elmer, Spectrum One), the absorption of hydroxyl groups in the vicinity of 3300 cm ⁻² has disappeared, and the obtained liquid contains the above acrylic-modified polybutadiene (4) as a main component. It was.

[Comparative Example 1]

  Liquid polybutadiene in which butadiene is polymerized with 1,2-bonds in a 300 ml glass reactor [trade name: G-2000 Nippon Soda Co., Ltd. number average molecular weight = 1,100 (6)] 200.0 g, 2,6 -Di-t-butyl-4-methylphenol (BHT) 0.14 g, 2,4-toluene diisocyanate (7) 22.0 g, 2-hydroxyethyl methacrylate (8) 16.0 g were charged, and the total volume was 60-70. By reacting at 5 ° C. for 5 hours, a transparent viscous liquid (9) was obtained. The reaction is traced by extracting a small amount of the reaction solution and measuring the IR spectrum of the reaction solution. When the 2,100-2,600 cm-1 (isocyanate group) peak of the IR spectrum disappears, the reaction is terminated. It was. It was the obtained viscous liquid, Comprising: The compound shown by said (9) was contained.

(Evaluation)
(1) Viscosity evaluation The liquid obtained in Example 1, the liquid obtained in Comparative Example 1, and the liquid polybutadiene used in the production thereof [trade name: G-2000 Nippon Soda Co., Ltd. number average molecular weight = 1 , 100], the viscosity was measured (measurement temperature: 45 ° C.) using a B-type viscometer manufactured by Tokyo Keiki. The results are shown in Table 1.

  As can be seen from Table 1, the liquid obtained in Example 1 whose main component is the acrylic modified polybutadiene of the present invention is Comparative Example 1 whose main component is polybutadiene in which methacrylic acid is bonded via a urethane bond. It can be seen that the viscosity is very low compared to the liquid obtained in the above and liquid polybutadiene having a hydroxyl group at the terminal.

(2) UV Curability Evaluation About the liquid obtained in Example 1 and the liquid obtained in Comparative Example 1, the UV curability was confirmed. Specifically, using a 760 FTIR spectrometer manufactured by Nicolet Magna, 4 phr of dimethoxyacetophenone was added as a radical initiator, and the measurement was performed at 25 ° C. The change rate of absorbance at a wavelength of 814 cm −1 was compared as the reaction rate.

  The result is shown in FIG. As shown in FIG. 1, it can be seen that the liquid obtained in Example 1 has higher UV curing characteristics than the liquid obtained in Comparative Example 1.

It is a graph which shows the confirmation result of UV curability of the liquid obtained in Example 1, and the liquid obtained in Comparative Example 1.

Claims (7)

  An acrylic-modified polybutadiene, wherein (meth) acrylic acid is directly ester-bonded to at least one end of a polymer chain in which 80% or more of the butadiene units constituting the polymer chain are composed of 1,2 bonds.   2. The acrylic-modified polybutadiene according to claim 1, wherein (meth) acrylic acid is ester-bonded directly to both ends of the polymer chain.   A number average molecular weight is 500-10000, The acrylic modified polybutadiene of Claim 1 or 2 characterized by the above-mentioned.   (Meth) acrylate is reacted in the presence of a catalyst with a hydroxyl group-containing polybutadiene in which 80% or more of the butadiene units constituting the polymer chain have a hydroxyl group at least at one end of the polymer chain consisting of 1,2 bonds. A process for producing an acrylic-modified polybutadiene characterized in that.   The method for producing an acrylic-modified polybutadiene according to claim 4, wherein the hydroxyl group-containing polybutadiene has hydroxyl groups at both ends.   The method for producing an acrylic-modified polybutadiene according to claim 4 or 5, wherein the catalyst is tetraalkoxytitanium.   The method for producing an acrylic-modified polybutadiene according to claim 4 or 5, wherein the catalyst is a dialkyltin dicarboxylate or a dialkyltin oxide.