JP2006297728A - Extrusion method constituted so as to control pressure of vent hole - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a venting-up phenomenon occurring at the time of extrusion of an extrusion system easy to cause a venting-up phenomenon. <P>SOLUTION: In an extrusion method, at least two vent holes are provided when the extrusion system producing at least 40 pts. of a byproduct when a charging raw material is set to 100 pts. and the pressure of one vent hole of them is controlled to 0.1 to 0.2 MPa in gauge pressure while the pressure of the other one vent hole is controlled to -0.09 MPa or below in gauge pressure. By this extrusion method, the occurrence of venting-up can be reduced and a system of every kind, especially the extrusion system causing a large amount of the byproduct can be extruded efficiently. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an extrusion method for reducing the occurrence of vent-up.

  An extrusion apparatus may be used for kneading and reaction of resin. At that time, a vent port is generally provided in the extrusion apparatus because it is necessary to remove by-products generated in or present in the extrusion apparatus. In particular, the vent port is usually set in a reduced pressure state.

  However, there is a problem that vent-up occurs in a specific case such as when there are many by-products.

  This invention is made | formed in view of the said subject which a prior art has, and aims at providing the extrusion method with which generation | occurrence | production of vent-up was reduced.

  As a result of intensive studies in view of the above problems, the present inventor has two or more vent ports when extruding a resin system that produces 40 parts or more of by-products when the input raw material is 100 parts, Provided is an extrusion method in which the pressure of one or more vent ports is controlled to 0.1 MPa or more and 0.2 MPa or less by gauge pressure, and the pressure of one or more other vent ports is controlled to -0.09 MPa or less by gauge pressure. did.

  According to this, since it has one or more vent ports under specific conditions and two or more vent ports are arranged, it is possible to reduce the occurrence of vent-up when removing by-products.

  The extrusion method of the present invention can reduce the occurrence of vent-up, and can efficiently extrude various systems, particularly extrusion systems that generate a large amount of by-products.

  The present invention has two or more vent ports when extruding a resin system that produces 40 parts or more of by-products when the input raw material is 100 parts, and the pressure of one or more of the vent ports is a gauge pressure. Is controlled to 0.1 MPa or more and 0.2 MPa or less, and further relates to an extrusion method in which the pressure of one or more other vent ports is controlled to −0.09 MPa or less by gauge pressure.

  Although the present invention can be applied to various extrusion systems, it is particularly effective to use it in a resin system that tends to cause vent-up and produces 40 parts or more of by-products when the input raw material is 100 parts. In particular, it can be effectively applied when performing an imidization reaction. Furthermore, it can be effectively applied to a reaction in which an acrylic resin or a copolymer resin of acryl and styrene is treated with an imidizing agent, particularly a reaction in which a PMMA resin or MS resin is treated with an imidizing agent.

  For example, in the imidization reaction, a large amount of by-products such as water, methanol, unreacted substances (imidizing agent, etc.) and decomposition products are generated. In the present invention, these by-products are vented up. Can be removed efficiently without any problems.

  Hereinafter, an example of a resin (product) that can be particularly preferably produced using the extrusion method of the present invention will be described.

(Resin composition)
The present invention is effective, for example, in the production of imide resins containing repeating units represented by the following general formulas (1), (2), and (3).

(Here, R ¹ and R ² each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ³ represents an alkyl group having 1 to 18 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms. Or an aryl group having 6 to 10 carbon atoms.)

(Here, R ⁴ and R ⁵ each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ⁶ represents an alkyl group having 1 to 18 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms. Or an aryl group having 6 to 10 carbon atoms.)

(Here, R ⁷ represents hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ⁸ represents an aryl group having 6 to 10 carbon atoms.)
Hereinafter, the repeating unit represented by the general formula (1) is a glutarimide unit, the repeating unit represented by the general formula (2) is a (meth) acrylate unit, and the repeating unit represented by the general formula (3) is Sometimes referred to as an aromatic vinyl unit.

As a preferred glutarimide unit, R ¹ and R ² are hydrogen or a methyl group, and R ³ is hydrogen, a methyl group, or a cyclohexyl group. The case where R ¹ is a methyl group, R ² is hydrogen, and R ³ is a methyl group is particularly preferred.

The glutarimide unit may be a single type or may include a plurality of types in which R ¹ , R ² , and R ³ are different.

  The monomer that gives the structure of the (meth) acrylic acid ester unit is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t- Examples include butyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like. In addition, acid anhydrides such as maleic anhydride or half esters of these and linear or branched alcohols having 1 to 20 carbon atoms; acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, Α, β-ethylenically unsaturated carboxylic acids such as crotonic acid, fumaric acid and citraconic acid can also be imidized and used in the present invention. Of these, methyl methacrylate is particularly preferred.

These (meth) acrylic acid ester units may be of a single type or may include a plurality of types in which R ⁴ , R ⁵ and R ⁶ are different.

  Preferred monomers that give an aromatic vinyl unit include styrene, α-methylstyrene, and the like. Of these, styrene is particularly preferred.

These aromatic vinyl units may be of a single type or may include a plurality of types in which R ⁷ and R ⁸ are different.

  The preferable content of the glutarimide unit in the imide resin is 1% to 95% by weight, more preferably 1.5 to 90% by weight, and still more preferably 2%, when the entire imide resin is 100% by weight. ~ 80% by weight. When a glutarimide unit is smaller than this range, the heat resistance of the imide resin obtained may be insufficient, or transparency may be impaired. On the other hand, if it exceeds this range, the heat resistance is unnecessarily increased and it becomes difficult to mold, and the mechanical strength of the resulting molded body becomes extremely brittle, and the transparency may be impaired.

  The preferable content of the aromatic vinyl unit in the imide resin is 7 to 80% by weight, more preferably 10 to 70% by weight, and still more preferably 10 to 70% by weight when the entire imide resin is 100% by weight. 60% by weight. When the aromatic vinyl unit is larger than this range, the heat resistance of the resulting imide resin is insufficient. When the aromatic vinyl unit is smaller than this range, the mechanical strength of the obtained molded article may be lowered.

  If necessary, the imide resin of the present invention may further be copolymerized with a fourth structural unit. A constitution obtained by copolymerizing a nitrile monomer such as acrylonitrile and methacrylonitrile, and a maleimide monomer such as maleimide, N-methylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide as the fourth structural unit Units can be used. These may be directly copolymerized in the imide resin or may be graft copolymerized.

  The imide resin preferably has a weight average molecular weight of 10,000 to 200,000. When the weight average molecular weight is not more than the above value, the mechanical strength of the molded product is insufficient. When the weight average molecular weight is not less than the above value, the viscosity at the time of melting may be high, and the productivity at the time of molding may be reduced. .

  The imide resin is used in cameras, VTRs, imaging lenses and finders for projectors, filters, prisms, Fresnel lenses, and other imaging fields, CD players, DVD players, MD players and other optical disc pickup lenses, CD players, Optical recording field for optical discs such as DVD players and MD players, liquid crystal light guide plates, liquid crystal display films such as polarizer protective films and retardation films, information equipment fields such as surface protective films, optical fibers, optical switches, light Optical communication fields such as connectors, automotive headlights, tail lamp lenses, inner lenses, instrument covers, sunroofs, and other vehicle fields, eyeglasses, contact lenses, internal vision lenses, medical devices such as medical supplies that require sterilization, road Light plate, lens for pair glass, lighting window and carport, lighting lens and cover, building and building materials field such as sizing for building materials, microwave oven cooking container (tableware), housing for home appliances, toys, sunglasses, stationery, etc. It is usable and useful.

  When producing the imide resin using the extrusion method of the present invention, a copolymer resin of acrylic and styrene, particularly MS resin (methyl methacrylate-styrene copolymer) can be suitably used as a raw material resin ( In the case of forming an imide resin having no aromatic vinyl unit and comprising a glutarimide unit and a (meth) acrylate unit, an acrylic resin, particularly a PMMA resin (polymethyl methacrylate) can be used. .) These raw resin may be a linear (linear) polymer, or may be a block polymer, a core-shell polymer, a branched polymer, a ladder polymer, or a crosslinked polymer. The block polymer may be an A-B type, A-B-C type, A-B-A type, or any other type of block polymer. There is no problem even if the core-shell polymer is composed of only one core and only one shell, or each layer is a multilayer.

  When the raw material resin is used and the imide resin is prepared using the extrusion method of the present invention, an imidizing agent is preferably used. Examples of imidizing agents include amines containing aliphatic hydrocarbon groups such as methylamine, ethylamine, n-propylamine, i-propylamine, n-butylamine, i-butylamine, tert-butylamine, n-hexylamine, and aniline. , Aromatic hydrocarbon group-containing amines such as toluidine and trichloroaniline, and alicyclic hydrocarbon group-containing amines such as cyclohexylamine. In addition, urea compounds that generate these amines by heating, such as urea, 1,3-dimethylurea, 1,3-diethylurea, and 1,3-dipropylurea can also be used. Of these imidizing agents, methylamine is preferable from the viewpoint of cost and physical properties.

  In addition, manufacture of the above imide resin is an example of reaction with much generation amount of a by-product, and it is easy to produce vent up, and this invention is not limited to these.

(Vent vent)
The extruder used in the present invention needs to have two or more vents, and it is necessary to control the pressure of one or more of the vent ports to 0.1 MPa or more and 0.2 MPa or less by gauge pressure. There is. When the gauge pressure is lower than 0.1 MPa, the vent-up cannot be sufficiently suppressed, and when the pressure is higher than 0.2 MPa, the removal efficiency of by-products is not preferable.

  Moreover, the pressure of one or more other vent ports needs to be controlled to −0.09 MPa or less. If the pressure at the vent port is higher than -0.09 MPa, the removal efficiency of by-products decreases, which is not preferable.

  In the present invention, the above-described two types of vent ports are necessary. For example, when only the former is provided, the removal efficiency of by-products is not preferable, and only the latter is provided. , Vent up can not be suppressed.

(Device configuration)
Various extruders can be used as an extruder that can be used in the present invention, but it is particularly preferable to apply to a twin-screw extruder because of its high kneading capacity. It is preferable to apply a direction meshing extruder.

  Various methods can be used to control the pressure at the vent port to 0.1 MPa or more and 0.2 MPa or less. For example, a valve is arranged on a pipe connecting the vent port and the atmospheric system, and the valve is opened. A method of adjusting the pressure in the vent port according to the degree is simple. Note that a valve may be automatically controlled based on a pressure gauge value.

  In addition, various methods can be used as a method for controlling the pressure at the vent port to −0.09 MPa or less. For example, a pipe communicating with the external air pressure is provided on a pipe connecting the vent and the pressure reducing device via a valve. A method of adjusting the pressure in the vent port according to the opening of the valve is simple. Note that a valve may be automatically controlled based on a pressure gauge value.

  An example of an extrusion system (side view) used in the present invention is shown in FIG.

(Vent up)
The vent-up here means a phenomenon that the resin goes up to the vent port for removing the by-product, and the cause is not particularly limited. For example, if the cause of the vent-up is that there are many by-products and the resin goes up to the vent port along with the by-products to remove the by-products, excessive supply of the discharged amount is performed. This may occur when

(apparatus)
As the extruder, a Technobel 40 mm in-direction meshing type extruder was used. Moreover, the screw length was implemented by the structure equivalent to L / D = 60.

  As the addition pump for the imidizing agent, an addition pump for high-pressure gas (made by Showa Carbon Dioxide) was used. Moreover, the constant weight feeder (made by Kubota) was used for supply of resin. Further, a dry roots pump (manufactured by Anlet) was used as the vacuum pump.

(Raw resin / imidizing agent)
As a PMMA resin, Sumipex MG (manufactured by Sumitomo Chemical) was used. Monomethylamine (Mitsubishi Gas Chemical Co., Ltd.) was used as the imidizing agent.

(Extrusion conditions)
The screw rotation speed was 150 rpm. Moreover, the addition part of the imidation agent added 40 parts with respect to 100 parts of resin. The feed amount of the resin was 30 kg / hr.

  The temperature of each cylinder was divided into 9 zones, which were 180 ° C, 230 ° C, 230 ° C, 230 ° C, 200 ° C, 230 ° C, 230 ° C, 230 ° C, and 230 ° C, respectively.

(analysis)
The strand discharged from the extruder was passed through a cooling bath, and then pelletized with a pelletizer, and the pellet was used as a sample. Whether the reaction was stable was determined by calculating the imidization rate by NMR measurement. Further, the amount of residual gas in the resin was measured by gas chromatography analysis.

(NMR measurement)
10 mg of a sample was dissolved in 1 g of CDCl _3, and ¹ H-NMR was measured at room temperature using a Varian NMR measuring apparatus Gemini-300. From the obtained spectrum, the imidization ratio was determined from the ratio of the absorption intensity attributed to the ester carbonyl group and the absorption intensity attributed to the imide carbonyl group.

(Gas chromatography analysis)
0.5 g of a sample was dissolved in 10 ml of dichloromethane and measured using a gas chromatograph GC-6890 + manufactured by Agilent-Technologies.

Example 1
The extrusion apparatus, extrusion conditions, raw material resin, and imidizing agent are as described in the previous section. Two vent ports were installed, and the first vent port (hereinafter referred to as “vent 1”) was adjusted with a valve so that the pressure was 0.1 MPa as a gauge pressure. The second vent port (hereinafter referred to as “vent 2”) was under a high vacuum of −0.1 MPa in terms of gauge pressure.

  After the reaction was stabilized under the conditions, the discharged resin was sampled and the amount of residual gas in the resin was analyzed. In addition, the presence or absence of vent-up of the vents 1 and 2 was observed. The results are shown in Table 1.

(Example 2)
Except that the discharge amount was adjusted so that the pressure of the vent 1 was 0.2 MPa as a gauge pressure, the operation was performed under the same conditions as in Example 1 and the reaction was stabilized. The amount of residual gas was analyzed. In addition, the presence or absence of vent-up of the vents 1 and 2 was observed. The results are shown in Table 1.

(Example 3)
Except that the discharge amount was adjusted so that the pressure of the vent 1 was 0.3 MPa as a gauge pressure, the operation was performed under the same conditions as in Example 1 and the reaction was stabilized. The amount of residual gas was analyzed. In addition, the presence or absence of vent-up of the vents 1 and 2 was observed. The results are shown in Table 1.

Example 4
Except that the degree of vacuum was adjusted so that the pressure of the vent 2 was −0.09 MPa as a gauge pressure, the operation was performed under the same conditions as in Example 1 and the reaction was stabilized. The amount of residual gas was analyzed. In addition, the presence or absence of vent-up of the vents 1 and 2 was observed. The results are shown in Table 1.

(Example 5)
Except that the degree of vacuum was adjusted so that the pressure of the vent 2 was −0.08 MPa as the gauge pressure, the operation was performed under the same conditions as in Example 1, and after the reaction was stabilized, the discharged resin was sampled. The amount of residual gas was analyzed. In addition, the presence or absence of vent-up of the vents 1 and 2 was observed. The results are shown in Table 1.

(Result of Example)
Vent up could be suppressed by setting the pressure of the vent 1 to 0.1 MPa or more by gauge pressure. However, when the pressure of the vent 1 was increased to 0.3 MPa, the residual gas amounts of methanol and trimethylamine in the discharged resin increased, which was not preferable.

  Moreover, when the pressure of the vent 2 was reduced to −0.08 MPa by gauge pressure, the residual gas amount of methanol in the discharged resin increased, which was not preferable.

(Comparative Example 1)
The extrusion apparatus, extrusion conditions, raw material resin, and imidizing agent are as described in the previous section. One vent port was installed and vent 1 was eliminated. The pressure of the vent 2 was 0 MPa (atmospheric pressure) as a gauge pressure. After the reaction was stabilized under the conditions, the discharged resin was sampled and the amount of residual gas in the resin was analyzed. In addition, the presence or absence of vent-up of the vent 2 was observed. The results are shown in Table 2.

(Comparative Example 2)
Except that the degree of vacuum was adjusted so that the pressure of the vent 2 was −0.09 MPa as the gauge pressure, the operation was performed under the same conditions as in Comparative Example 1 and the reaction was stabilized. The amount of residual gas was analyzed. In addition, the presence or absence of vent-up of the vent 2 was observed. The results are shown in Table 2.

(Comparative Example 3)
The extrusion apparatus, extrusion conditions, raw material resin, and imidizing agent are as described in the previous section. Two vent ports were installed, and the pressure of the vent 1 was 0 MPa (atmospheric pressure) as a gauge pressure. Further, the degree of vacuum was adjusted so that the pressure of the vent 2 was -0.09 MPa as a gauge pressure. After the reaction was stabilized under the conditions, the discharged resin was sampled and the amount of residual gas in the resin was analyzed. In addition, the presence or absence of vent-up of the vents 1 and 2 was observed. The results are shown in Table 2.

(Result of comparative example)
As shown in Table 2, vent-up occurred in all cases. Further, in the case of only the vent 2 (only one), the amount of residual gas of methanol or trimethylamine in the discharged resin is increased, which is not preferable.

Example of extrusion system (side view) used in the present invention

Explanation of symbols

1 Extruder 2 Vent 1
3 Vent 2
4 valve 5 pressure gauge of vent 1 6 pressure gauge of vent 2 7 liquid addition port 8 constant weight feeder 9 addition pump 10 vacuum pump

Claims (6)

  When extruding a resin system that produces 40 parts or more of by-products when the input raw material is 100 parts, it has two or more vent ports, and the pressure of one or more of the vent ports is 0.1 MPa in terms of gauge pressure. As mentioned above, the extrusion method characterized by controlling to 0.2 MPa or less, and further controlling the pressure of one or more other vent ports to -0.09 MPa or less by gauge pressure.   2. The extrusion method according to claim 1, wherein a twin screw extruder is used.   The extrusion method according to any one of claims 1 and 2, wherein a twin-shaft, same-direction meshing type extruder is used.   The extrusion method according to any one of claims 1 to 3, wherein the extrusion method is used in an imidization reaction.   The extrusion method according to any one of claims 1 to 4, wherein the imidization reaction is a reaction in which an acrylic resin or a copolymer resin of acryl and styrene is treated with an imidizing agent.   The extrusion method according to any one of claims 1 to 5, wherein the imidization reaction is a reaction of treating PMMA resin or MS resin with an imidizing agent.

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