JP2005350594A - Solution of n-substituted maleimide-olefin copolymer having excellent storage stability and method for producing film using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a solution of an N-substituted maleimide-olefin copolymer having excellent storage stability in long-term preservation and to provide a method for producing a film using the same. <P>SOLUTION: The solution of an N-substituted maleimide-olefin copolymer comprises 10-40 wt.% of an N-substituted maleimide-olefin copolymer and 90-60 wt.% of a mixed solvent composed of 1-40 wt.% of a nitrile-based solvent and 99-60 wt.% of a halogen-based solvent and has excellent storage stability. The method for producing the film of an N-substituted maleimide-olefin copolymer comprises using the solution of the N-substituted maleimide-olefin copolymer and removing the solvent from the solution. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an N-substituted maleimide / olefin copolymer solution excellent in storage stability during long-term storage and a method for producing a film using the N-substituted maleimide / olefin copolymer solution excellent in storage stability. Is.

  N-substituted maleimide / olefin resin is disclosed to be an optical material that is transparent and has low birefringence and is excellent in heat resistance, surface hardness, and mechanical strength (see, for example, Patent Document 1).

  And as a manufacturing method of the film at the time of using resin as a film, the melting method or the casting method is known.

JP 05-117334 A

  However, when an N-substituted maleimide / olefin resin film is produced by the casting method, when the solution viscosity of the N-substituted maleimide / olefin resin solution for casting is low, the film is wet in the initial state of film drying. There has been a problem that an orange peel caused by convection is generated on the film, and the surface smoothness tends to be lowered.

  As a method for solving the orange peel, a method of increasing the solution viscosity by increasing the concentration of the N-substituted maleimide / olefin resin solution can be considered, but the solution concentration of the N-substituted maleimide / olefin resin solution is increased and the solution viscosity is increased. N-substituted maleimide / olefin copolymer having excellent solution stability without the occurrence of gelation, and the storage stability of the N-substituted maleimide / olefin resin solution is reduced. The appearance of a coalescence solution was eagerly desired.

  As a result of intensive studies to solve the above problems, the inventors of the present invention comprise an N-substituted maleimide / olefin copolymer and a specific mixed solvent containing a specific solvent selected from a poor solvent or a non-solvent. The present inventors have found that an N-substituted maleimide / olefin copolymer solution has excellent solution stability without generation of gelation, and completed the present invention.

  That is, the present invention is an N-substituted maleimide / olefin copolymer comprising 10 to 40% by weight of an olefin residue unit represented by the following formula (i) and an N-substituted maleimide residue unit represented by the following formula (ii). And an N-substituted maleimide / olefin copolymer solution having excellent storage stability comprising 90 to 60% by weight of a mixed solvent comprising 1 to 40% by weight of a nitrile solvent and 99 to 60% by weight of a halogen solvent, and the N -It is related with the manufacturing method of the film which uses a substituted maleimide olefin copolymer solution.

（ここで、Ｒ１、Ｒ２はそれぞれ独立して、水素、炭素数１〜６のアルキル基、炭素数３〜６のシクロアルキル基を示す。）

(Here, R1 and R2 each independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms.)

（ここで、Ｒ３は炭素数１〜２０のアルキル基、炭素数３〜８のシクロアルキル基、炭素数６〜２４の芳香族基、アルキル置換芳香族基を示す。）
以下に、本発明に関し詳細に説明する。

(Here, R3 represents an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aromatic group having 6 to 24 carbon atoms, or an alkyl-substituted aromatic group.)
The present invention will be described in detail below.

  The N-substituted maleimide / olefin copolymer constituting the present invention includes a copolymer comprising an olefin residue unit represented by the above formula (i) and an N-substituted maleimide residue unit represented by the above formula (ii). It is. Here, R1 and R2 are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include, for example, a methyl group , An ethyl group, a propyl group, a butyl group, a heptyl group, a hexyl group, and the like. Examples of the cycloalkyl group having 3 to 6 carbon atoms include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group. it can. R3 is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aromatic group having 6 to 24 carbon atoms, or an alkyl-substituted aromatic group, and the alkyl group having 1 to 20 carbon atoms Examples of the cycloalkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a heptyl group, a hexyl group, and an octyl group. Examples of the cycloalkyl group having 3 to 8 carbon atoms include a cyclopropyl group and a cyclobutyl group. Group, cyclohexyl group and the like. Examples of the aromatic group having 6 to 24 carbon atoms and the alkyl-substituted aromatic group include a phenyl group, an o-methylphenyl group, an o-ethylphenyl group, and an o-propylphenyl group. M-methylphenyl group, m-ethylphenyl group, m-propylphenyl group, p-methylphenyl group, p-ethylphenyl group, p-propylphenyl group, , P- dimethylphenyl group, o, p- diethyl phenyl group, o, p- dipropyl phenyl group and a naphthyl group.

  Specific examples of the N-substituted maleimide / olefin copolymer include N-phenylmaleimide / isobutene copolymer, N-phenylmaleimide / ethylene copolymer, N-phenylmaleimide / 2-methyl-1-butene copolymer, and the like. Polymer, N- (2-methylphenyl) maleimide / isobutene copolymer, N- (2-methylphenyl) maleimide / ethylene copolymer, N- (2-methylphenyl) maleimide / 2-methyl-1-butene Copolymer, N- (2-ethylphenyl) maleimide / isobutene copolymer, N- (2-ethylphenyl) maleimide / ethylene copolymer, N- (2-ethylphenyl) maleimide / 2-methyl-1- Butene copolymer, N-methylmaleimide / isobutene copolymer, N-methylmaleimide / ethylene copolymer, N-methyl Reimide / 2-methyl-1-butene copolymer, N-cyclohexylmaleimide / isobutene copolymer, N-cyclohexylmaleimide / ethylene copolymer, N-cyclohexylmaleimide / 2-methyl-1-butene copolymer, etc. Among them, an N-substituted maleimide / olefin copolymer solution having particularly excellent storage stability and a film having excellent heat resistance, transparency, and mechanical properties can be obtained. An isobutene copolymer, an N-methylmaleimide / isobutene copolymer, and an N-cyclohexylmaleimide / isobutene copolymer are preferred.

  The N-substituted maleimide / olefin copolymer includes an olefin compound that derives an olefin residue unit represented by the formula (i) and a maleimide compound that derives an N-substituted maleimide residue unit represented by the formula (ii). Can be obtained by utilizing a known polymerization method. Examples of the polymerization method at that time include a bulk polymerization method, a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method. The N-substituted maleimide / olefin copolymer can also be obtained by a method of dehydrating and ring-closing imidizing an amide oxide obtained by reacting maleic anhydride / olefin copolymer with ammonia and an amine compound. is there.

  The mixed solvent used in the present invention comprises 1 to 40% by weight of a nitrile solvent and 99 to 60% by weight of a halogen solvent, and becomes an N-substituted maleimide / olefin copolymer solution particularly excellent in storage stability. From the standpoint of excellent moldability during film production, it is preferable to comprise 1 to 20% by weight of a nitrile solvent and 99 to 80% by weight of a halogen solvent. Here, when the nitrile solvent exceeds 40% by weight, the storage stability of the N-substituted maleimide / olefin copolymer solution decreases, or the solubility of the N-substituted maleimide / olefin copolymer solution decreases remarkably. Cannot be obtained. On the other hand, when the nitrile solvent is less than 1% by weight, the storage stability of the resulting N-substituted maleimide / olefin copolymer solution is lowered.

  The nitrile solvent in the present invention acts as a poor solvent or non-solvent for the N-substituted maleimide / olefin copolymer, and only the good solvent is obtained by adding the nitrile solvent as a poor solvent or non-solvent. It is possible to lower the solution viscosity as compared with a solution having the same concentration by using sol alone, and the storage stability of the N-substituted maleimide / olefin copolymer solution can be further improved. Examples of the nitrile solvent include acetonitrile, propanenitrile, butanenitrile, phenylacetonitrile, and the like. Among them, acetonitrile becomes a N-substituted maleimide / olefin copolymer solution particularly excellent in storage stability. Is preferred.

  The halogen solvent in the present invention acts as a good solvent for the N-substituted maleimide / olefin copolymer. Examples of the halogen solvent include methylene chloride, chloroform, 1,2-dichloroethane, 1,1. , 2-trichloroethane, chlorobenzene, dichlorobenzene, and the like, and in particular, methylene chloride is preferable because the N-substituted maleimide / olefin copolymer is excellent in solubility and storage stability.

  The N-substituted maleimide / olefin copolymer solution of the present invention comprises 10 to 40% by weight of the N-substituted maleimide / olefin copolymer and 90 to 60% by weight of the mixed solvent, and is particularly excellent in storage stability. The N-substituted maleimide / olefin copolymer solution is preferably 20 to 30% by weight of the N-substituted maleimide / olefin copolymer and 80 to 70% by weight of the mixed solvent. Here, when the N-substituted maleimide / olefin copolymer is less than 10% by weight, the solution concentration is low. It occurs and tends to be a film with reduced surface smoothness. On the other hand, when the N-substituted maleimide / olefin copolymer exceeds 40% by weight, when the solution is stored for a long time, gelation occurs due to aggregation of the N-substituted maleimide / olefin copolymer, resulting in poor storage stability. It becomes.

  The method for producing the N-substituted maleimide / olefin copolymer solution of the present invention is not particularly limited, and even if a mixed solvent is added to the N-substituted maleimide / olefin copolymer, the N-substituted maleimide / olefin is added to the mixed solvent. A copolymer may be added. The mixed solvent may be a mixed solvent obtained by mixing a nitrile solvent and a halogen solvent in advance, or may be independently added to the N-substituted maleimide / olefin copolymer to finally form a mixed solution. When the N-substituted maleimide / olefin copolymer solution of the present invention is produced, the dissolution rate of the N-substituted maleimide / olefin copolymer is increased, so that the form of the N-substituted maleimide / olefin copolymer is increased. It is preferable to use powder.

  Further, the N-substituted maleimide / olefin copolymer of the present invention is usually a polyamide, a styrene / acrylonitrile copolymer, an acrylonitrile / acrylic copolymer, which is used for a resin, a resin composition, a film or the like, without departing from the object of the present invention. Thermoplastic resin such as butadiene / styrene copolymer, polycarbonate, polyethylene terephthalate, polystyrene, acrylic resin, polyglutarimide; UV absorber, near infrared absorber, antioxidant, light stabilizer, weather stabilizer, flame retardant In addition, additives such as a plasticizer may be blended.

  The N-substituted maleimide / olefin copolymer solution of the present invention is excellent in storage stability because of its excellent storage stability, and particularly excellent in film moldability by the casting method.

  Below, an example at the time of manufacturing a film by the casting method using the N-substituted maleimide olefin copolymer solution of this invention is shown.

  (1) A step of casting the N-substituted maleimide / olefin copolymer solution of the present invention on a support to form a cast film containing a solvent (hereinafter sometimes referred to as a casting step). Next, the film can be produced by (2) a step of evaporating the solvent from the cast film (hereinafter sometimes referred to as a drying step).

  The casting step is a step of casting an N-substituted maleimide / olefin copolymer solution on a support to form a cast film on the support. In this step, the N-substituted maleimide / olefin copolymer solution of the present invention is cast on a support such as an endless band drum using, for example, a comma coater, a lip coater, a doctor blade coater, a bar coater, or a roll coater. It is common to do. Note that it is preferable to use a mirror-finished metal such as stainless steel, a resin film such as polyethylene terephthalate, glass, or the like for the support.

  The drying step is a step of evaporating the solvent from the cast film to form an N-substituted maleimide / olefin copolymer film. The evaporation of the solvent is preferably performed by heating in order to improve the solvent removal efficiency. Heating may be performed at a constant temperature, but it is preferable to change the temperature over several steps from the viewpoint of economy and smoothness of the film surface. Further, since the N-substituted maleimide / olefin copolymer film obtained is excellent in heat resistance, dimensional accuracy, and low hygroscopicity, the amount of residual solvent in the N-substituted maleimide / olefin copolymer film is 5% by weight. It is preferable to carry out until it becomes less than or equal to%, particularly 1% by weight or less, and further preferably 0.5% or less. In addition, the drying temperature at that time is more than the glass transition temperature of the N-substituted maleimide / olefin copolymer to be used because it becomes possible to produce an N-substituted maleimide / olefin copolymer film particularly with high production efficiency. It is preferable that

  Further, the produced N-substituted maleimide / olefin copolymer film is usually used after being peeled from the support. There is no restriction | limiting in particular in the method of peeling, A long N- substituted maleimide olefin copolymer film can be obtained by peeling a film-like material from a support body continuously. A short N-substituted maleimide / olefin copolymer film can also be obtained by a batch method using a sheet-like support.

  For example, in the field of electrical insulation, the N-substituted maleimide / olefin copolymer film is coated with an insulating material such as a class H electrical device, a slot liner for a motor or a generator, an interphase insulation, an adhesive, or an adhesive. It can be used for tape-shaped transformers, wrapping materials for electric wires, dielectric films such as capacitors, and tubular insulating materials. In the field of electronics, it can be used for flexible printed circuit boards, their reinforcing plates, heat resistant spacers, PCB laminates and the like. In the acoustic related field, it can be used for a diaphragm or a vibration reinforcing plate of a speaker. In the information-related field, recording tapes, disks, liquid crystal display glass substrate substitute films that require dimensional stability, and stretching can be used for retardation films and optical fiber connections. In the food and medical fields, it can be used for medical sterilization equipment, heating packs for microwave ovens and microwave ovens, and the like.

  The N-substituted maleimide / olefin copolymer solution of the present invention has the storage stability that was a problem of the N-substituted maleimide / olefin copolymer solution by using a mixed solvent composed of a halogen-based solution and a nitrile solvent. It became possible to improve.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The measuring method of each physical property value in the examples is shown below.

-Measurement of weight average molecular weight and number average molecular weight-
Based on an elution curve measured using gel permeation chromatography (GPC) (trade name HLC-802A, manufactured by Tosoh Corporation), a weight average molecular weight (Mw), a number average molecular weight (Mn) and a standard polystyrene conversion value. The molecular weight distribution (Mw / Mn) as the ratio was measured.

~ Measurement of glass transition temperature ~
Using a differential heat measuring device (trade name DSC2000, manufactured by Seiko Denshi Kogyo), 10 ° C./min. It measured at the temperature increase rate of.

~ Measurement of haze ~
As an evaluation of transparency, haze was measured according to JIS K 7136 (2000 version).

Synthesis Example 1 (Production of N-phenylmaleimide / isobutene copolymer)
In a 3 liter autoclave equipped with a stirrer, pressure gauge, thermometer, nitrogen introduction tube, olefin introduction tube and degassing tube, 128 g (0.74 mol) of N-phenylmaleimide and 0.19 g (0. 76 mmol) and 390 g of methyl ethyl ketone, purged several times with nitrogen, and then charged with 148 ml (1.48 mol) of liquefied isobutene and reacted at 60 ° C. for 8 hours to give an N-phenylmaleimide-isobutene copolymer (weight average molecular weight). (Mw) = 161000, weight average molecular weight (Mw) / number average molecular weight (Mn) = 2.05).

Example 1
12.5 g of N-phenylmaleimide / isobutene copolymer obtained in Synthesis Example 1, 37.125 g of methylene chloride and 0.375 g of acetonitrile were used as a mixed solvent (methylene chloride: acetonitrile = 99: 1 (weight ratio)). -A 25% by weight solution of phenylmaleimide / isobutene copolymer was prepared.

  When the N-phenylmaleimide / isobutene copolymer 25% by weight solution was allowed to stand at 25 ° C. for 1 month to confirm the storage stability, no gelation was observed.

  Further, a 25% by weight N-phenylmaleimide / isobutene copolymer solution after observation of storage stability was cast on a polyethylene terephthalate film (hereinafter referred to as PET film), and methylene chloride and acetonitrile were added from the solution. The N-phenylmaleimide / isobutene copolymer film formed by volatilization and then solidified was peeled off and collected. The film is further dried at 100 ° C. for 4 hours, from 120 ° C. to 160 ° C. at 10 ° C. intervals for 1 hour, and then vacuum-dried at 180 ° C. for 4 hours to have a thickness of about 100 μm. A film was obtained. The obtained N-phenylmaleimide / isobutene copolymer film had a haze of 0.3%. Each evaluation result is shown in Table 1.

Example 2
Example 1 except that 35.625 g instead of 37.125 g of methylene chloride and 1.875 g instead of 0.375 g of acetonitrile were used as a mixed solvent (methylene chloride: acetonitrile = 95: 5 (weight ratio)). According to the method, a 25% by weight N-phenylmaleimide / isobutene copolymer solution and an N-phenylmaleimide / isobutene copolymer film were prepared.

  The obtained N-phenylmaleimide / isobutene copolymer 25% by weight solution was excellent in storage stability with no gelation observed even at 25 ° C. for 1 month. Further, the haze of the obtained N-phenylmaleimide / isobutene copolymer film was 0.5%. Each evaluation result is shown in Table 1.

Example 3
Except for the mixed solvent (methylene chloride: acetonitrile = 90: 10 (weight ratio)) of 33.75 g instead of 37.125 g of methylene chloride and 3.75 g instead of 0.375 g of acetonitrile, the same as in Example 1. According to the method, a 25% by weight N-phenylmaleimide / isobutene copolymer solution and an N-phenylmaleimide / isobutene copolymer film were prepared.

  The obtained N-phenylmaleimide / isobutene copolymer 25% by weight solution was excellent in storage stability with no gelation observed even at 25 ° C. for 1 month. Further, the haze of the obtained N-phenylmaleimide / isobutene copolymer film was 0.4%. Each evaluation result is shown in Table 1.

Example 4
According to the same method as in Example 1 except that 30 g instead of 37.125 g of methylene chloride and 7.5 g instead of 0.375 g of acetonitrile were used as a mixed solvent (methylene chloride: acetonitrile = 80: 20 (weight ratio)). N-phenylmaleimide / isobutene copolymer 25% by weight solution and N-phenylmaleimide / isobutene copolymer film were prepared.

  The obtained N-phenylmaleimide / isobutene copolymer 25% by weight solution was excellent in storage stability with no gelation observed even at 25 ° C. for 1 month. Further, the haze of the obtained N-phenylmaleimide / isobutene copolymer film was 0.5%. Each evaluation result is shown in Table 1.

Example 5
According to the same method as in Example 1, except that 22.5 g instead of 37.125 g of methylene chloride and 15 g instead of 0.375 g of acetonitrile were used as a mixed solvent (methylene chloride: acetonitrile = 60: 40 (weight ratio)). N-phenylmaleimide / isobutene copolymer 25% by weight solution and N-phenylmaleimide / isobutene copolymer film were prepared.

  The obtained N-phenylmaleimide / isobutene copolymer 25% by weight solution was excellent in storage stability with no gelation observed even at 25 ° C. for 1 month. Further, the haze of the obtained N-phenylmaleimide / isobutene copolymer film was 1.0%. Each evaluation result is shown in Table 1.

Comparative Example 1
A 25% by weight N-phenylmaleimide / isobutene copolymer solution was prepared from 12.5 g of the N-phenylmaleimide / isobutene copolymer obtained in Synthesis Example 1 and 37.5 g of methylene chloride.

  When the 25% by weight solution of the N-phenylmaleimide / isobutene copolymer was allowed to stand at 25 ° C., it gelled in one day and a film could not be obtained. The respective evaluation results are shown in Table 2.

Comparative Example 2
Example 1 except that 18.75 g instead of 37.125 g of methylene chloride and 18.75 g instead of 0.375 g of acetonitrile were used as a mixed solvent (methylene chloride: acetonitrile = 50: 50 (weight ratio)). By the method, an attempt was made to prepare an N-phenylmaleimide / isobutene copolymer 25% by weight solution and an N-phenylmaleimide / isobutene copolymer film.

  However, the 25% by weight solution of the N-phenylmaleimide / isobutene copolymer was cloudy and was not suitable as a solution for casting, and a film could not be obtained. The respective evaluation results are shown in Table 2.

Claims (5)

10 to 40% by weight of an N-substituted maleimide / olefin copolymer comprising an olefin residue unit represented by the following formula (i) and an N-substituted maleimide residue unit represented by the following formula (ii), and a nitrile solvent An N-substituted maleimide / olefin copolymer solution having excellent storage stability, comprising 90 to 60% by weight of a mixed solvent comprising 1 to 40% by weight and a halogen solvent 99 to 60% by weight.

(Here, R1 and R2 each independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms.)

(Here, R3 represents an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aromatic group having 6 to 24 carbon atoms, or an alkyl-substituted aromatic group.) At least one N-substituted maleimide / olefin copolymer selected from the group consisting of N-methylmaleimide / isobutene copolymer, N-cyclohexylmaleimide / isobutene copolymer, N-phenylmaleimide / isobutene copolymer, The N-substituted maleimide / olefin copolymer solution having excellent storage stability according to claim 1. 3. The N-substituted maleimide / olefin copolymer solution with excellent storage stability according to claim 1, wherein the nitrile solvent is acetonitrile. The N-substituted maleimide / olefin copolymer solution having excellent storage stability according to claim 1, wherein the halogen-based solvent is methylene chloride. A method for producing an N-substituted maleimide / olefin copolymer film, wherein the N-substituted maleimide / olefin copolymer solution according to claim 1 is used, and the solvent is removed from the solution.