JPS6020907A - Production of molding polymer composition - Google Patents

Abstract

PURPOSE:To obtain a 1-methyl-4-ethenylbenzene polymer composition capable of forming moldings excellent in appearance and transparency, by adjusting the amount of solvent-insoluble components in a resin composition to a value within a specified range and polymerizing the monomer. CONSTITUTION:In producing a polymer composition containing a polymer comprising at least 30wt% monomer mixture comprising at least 85wt% 1-methyl-4- ethenylbenzene, 0-0.1wt% 1-methyl-2-ethenylbenzene, and 0-15wt% 1-methyl-3- ethenylbenzene, and 0-70wt% monomer copolymerizable with the monomer mixture (e.g., acrylonitrile, methacrylic acid, or styrene); the amount of tetrahydrofuran-insoluble component in the composition is adjusted to 0.0005-0.010 wt%, based on the composition. A molding polymer composition capable of forming transparent moldings of markedly improve appearance can be obtained, and it can be used in, for example, electric parts such as record player dust covers and fan impellers, or as an optical resin material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transparent molding polymer composition, and more particularly to a method for producing a transparent 1-methyl-4-ethynylbenzene polymer composition with improved appearance.

0 to 1% by weight of 1-methyl-2-ethynylbenzene, 0 to 15% by weight of 1-methyl-3-ethynylbenzene and at least 85% by weight of 1-methyl-4-
A monomer mixture such as ethynylbenzene (r PM
A polymer (hereinafter abbreviated as "r PMS polymer") consisting of at least 30% by weight of "S mixture") and at least 30% by weight of monomers copolymerizable with the monomer mixture (hereinafter abbreviated as "r PMS-based polymer") A transparent molding polymer composition (hereinafter abbreviated as "rPMs-based polymer composition") has, for example, a higher heat resistance and a higher temperature resistance than a styrenic polymer composition containing styrene as a polymer component. It is known to have characteristics such as good workability. Such PMS polymer compositions are disclosed, for example, in JP-A-54-145784 and JP-A-55-123627.

However, in such transparent PMS polymer compositions, linear patterns etc. occur on the surface of the molded product, which not only deteriorates the appearance of the transparent molded product but also hinders the functionality of the molded product in optical applications etc. There are problems such as the above fatal flaw.

In view of the importance of this problem, the present inventors have discovered that such linear patterns can be virtually eliminated by adjusting the weight of the component insoluble in sharp solvents within a specific range. Heading The present invention has been arrived at.

That is, the present invention provides O to 0.1% by weight of 1-methyl-2
- Ethynylbenzene, 0 not L15ffijt% 1-
at least 30% by weight of a monomer mixture consisting of methyl-3-ethynylbenzene and at least 85% by weight of 1-methyl-4-ethynylbenzene and 0 monomers copolymerizable with said monomer mixture. In the production of a transparent molding polymer composition containing a polymer comprising from 0.0005 to 0.010% by weight of the composition, the amount of N of the component insoluble in tetrahydrofuran in the composition is from 0.0005 to 0.010% by weight of the composition. % of the transparent molding polymer composition.

The PMS mixture referred to in the present invention is, for example, JP-A-53-1
This is a mixture as disclosed in Japanese Patent No. 47031.

The PMS polymer referred to in the present invention includes, for example, JP-A No. 54
Among the PMS-based polymers disclosed in Japanese Patent Publication No.-145784, transparent PMS-based polymers are included.

For example, a polymer of the PMS mixture itself, a monomer copolymerizable with the PMS mixture, such as styrene, alkyl or -logon substituted styrene such as α-methylstyrene, bromustyrene, acrylonitrile, methyl methacrylate. , a copolymer with one or more monomers selected from methacrylic acid, maleic anhydride, etc.
Preferably, a polymer of the FMS mixture itself, a copolymer of the PMS mixture and acrylonitrile, a copolymer of the PMS mixture and styrene, and a copolymer of the PMS mixture and methyl methacrylate are used.

In the present invention, the transparent molding polymer composition containing a PMS-based polymer refers to the PMS-based polymer itself or PM
In addition to S-based polymers, other single polymers, or styrene-based polymers, include binder agents, mold release agents, flame retardants, light,
Including those containing one or more stabilizers against heat and oxygen. The transparent molding polymer composition as used in the present invention is
This is a molding polymer composition having a light transmittance of 7.5% or more based on the light transmittance measuring method specified in JXS K 6717. In addition, when measured based on the method of JIS K 6717, a normal methyl methacrylate polymer composition has a polymer composition of 91 or more, and a styrene polymer composition has a polymer composition of 84 or more.
It shows a light transmittance of about 86 inches.

In the present invention, the weight of the component insoluble in tetrahydrofuran in the transparent molding polymer composition containing the PMS polymer is 0.0005 to 0.01% by weight of the composition, preferably 0.0005% by weight of the composition. It must be manufactured by adjusting the amount to 0.005% by weight. 0.01% by weight of such insoluble components
If this value is exceeded, linear patterns will appear on the surface of the molded product, and the appearance value as a transparent molded product will be significantly reduced.

Further, if the insoluble component is adjusted to less than 0.0005 parts by weight, not only will industrial production costs be large, but the composition will have properties that are undesirable as a transparent molding material.

For example, the PMS mixture is polymerized alone or copolymerized with other copolymerizable monomers, and the polymerization is stopped when the conversion rate of monomer to polymer is 30 to 90% by weight, preferably 40 to 70% by weight. However, there is a method of dissolving it in toluene or the like and drying it under vacuum at 100 to 120°C to separate a part of the monomer and solvent, and then passing through a pulverization process and an extrusion process to form a form that can be molded. This method requires complicated steps and a large amount of cost, and when the polymer is used as an acid-expanding material with a large amount of volatile components remaining in the polymer, it causes poor appearance of the molded product due to silver streaks originating from the volatile components. There is a problem that the heat resistance of the molded product is low, and this method is unsuitable as a method for manufacturing industrial molding materials.

The weight percent of the tetrahydrofuran-insoluble component in the molding polymer composition as used in the present invention is determined as follows. Accurately weigh approximately IQQgr of the polymer composition (xg) L, approximately 10.0
Add 0 cc of Tetrahydro7ran and dissolve. 40
Create a basket with an open top with a -side of 5 cIrL using 0 metal stainless steel gold copper. After thorough washing with tetrahydrofuran, the mixture was dried under vacuum (10 torr) at 80° C. for 6 hours, and then left in a desiccator at room temperature overnight and weighed at 7 lbs. The above-mentioned solution of the polymer composition is passed through this copper ring, and the solution passage section is thoroughly washed with tetrahydrofuran, so that only the components insoluble in the solution remain in the gold copper. After washing, it was dried under vacuum (10 torr) at 80° C. for 6 hours, and then left in a desiccator at room temperature for a day and night.The weight was accurately weighed (ysgr) and the weight percent of the cine-soluble component was calculated using the following formula.

Weight % of insoluble components d(y2-yt)÷x×100 In such a measurement, y1ey! is rounded to the unit of o, i mp. The effect of the composition of the present invention on the appearance of molded products is as follows:
Because it is achieved by adjusting the amount of extremely small amounts of insoluble components, ordinary measurements of insoluble components are difficult.
It must be measured with improved accuracy of three orders of magnitude or more.

The amount of insoluble components referred to in the present invention can be adjusted by selecting conditions particularly in the step of removing and/or reducing residual volatile components in the PMS polymer when producing the PMS polymer composition. It will be done. Although this step may vary depending on the method for producing a PMS polymer composition, a step in which the equipment and conditions of the step in a known method for producing a styrenic polymer composition are modified is usually used. Generally, under the conditions for producing a polymer containing styrene as a polymer constituent, when producing a PMS polymer by replacing all or part of styrene with a PMS mixture, it is necessary to The amount of components insoluble in tetrahydrofuran tends to be larger than the range of the present invention, but in order to obtain a PMS polymer composition with excellent appearance, the amount of the component insoluble in tetrahydrofuran is adjusted within the range of the present invention. need to be adopted. As means for such adjustment, for example, in the suspension polymerization method, selection of the amount and temperature of decomposition of the polymerization catalyst at the time of completion of polymerization (in the range of 80 to 99q6 monomer conversion rate), and uniform distribution of the polymerization catalyst are carried out. , or selection of conditions in one or more steps, such as the temperature and time during steam stripping treatment, or the extrusion temperature and residence time in the extruder and residence time distribution in the granulation step using an extruder after the polymerization step. can be given. In addition, in the solution or bulk polymerization method, the conditions in one or more steps, such as the temperature and residence time distribution in the devolatilization step after the completion of polymerization, or the temperature and residence time and residence time distribution in the subsequent extrusion granulation step, etc. The selection of will be the means of adjustment. Generally, in such a process, the higher the temperature, the longer the residence time, and the less uniform the residence time distribution and the distribution of the polymerization catalyst are, the more insoluble components tend to increase. Those skilled in the art can select these conditions by trial and error to adopt a production method for adjusting the components insoluble in tetrahydrofuran as defined in the present invention to within the range of the present invention. Regarding the relationship between the amount of components insoluble in tetrahydrofuran and the amount of 1-methyl-4-ethynylbenzene remaining in the polymer composition, in the above-mentioned method, generally speaking, as the amount of insoluble components decreases, the amount of 1-methyl-4-ethynylbenzene remaining in the polymer composition decreases.
The amount of methyl-4-ethynylbenzene tends to increase. However, using a devolatilization device consisting of one or more heaters and a vacuum chamber connected to one or more reactors, the amount of insoluble components of the polymer obtained by continuous bulk or solution polymerization can be completely controlled. In the case of adjustment, the amount of 1-methyl-4-ethynylbenzene remaining in the molding polymer composition should be less than 3% by weight, and at the same time the amount of insoluble components should be 0.5% by weight.
A method of adjusting the content to 0.0005 to 0.010% by weight can be adopted, and is a preferred method for carrying out the present invention. When producing the composition of the present invention, irradiation with gamma rays or other radiation is undesirable in order to maintain a good appearance of transparent molded products and should be avoided. In addition, the components insoluble in tetrahydrofuran referred to in the present invention are distinguished from those generated due to the adhesion of dull components to the reactor wall in the conventional resin composition production process, and are as described above.
This method is characterized in that it is a method for adjusting residual volatile components in a PMS polymer in the step of removing and/or reducing them. In addition, in the composition of the present invention, the amount of 1-methyl-4-ethynylbenzene remaining in the resin composition is determined in order to prevent silver streaking that occurs during molding of a transparent resin composition. 0.3fti%, preferably 0.2% by weight, particularly preferably 10% by weight
It is preferable to make it less than. The amount of nee-methyl-4-ethynylbenzene is measured using gas chromatography.

The transparent polymer composition obtained by the method of the present invention can be molded, for example, by an injection molding method, an extrusion molding method, a vacuum molding method,
Particularly, injection molding is preferably used, and the molded product is finally put into practical use.

The transparent molding polymer composition obtained by the method of the present invention is an FMS polymer composition that has a significantly improved appearance when molded into a molded product and a significantly increased commercial value of a transparent molded product. Products of extremely high industrial value are manufactured, such as electrical parts such as record player dust covers and electric fan blades, and optical resin materials.

Next, the present invention will be specifically explained using Examples and Comparative Examples.

Example 1 a. Method for producing a PMS polymer composition: 100 parts by weight of a PMS mixture (manufactured by Mobil Oil) was continuously fed as a raw material into a stirred tank reactor, average residence time was 2 hours, and polymerization temperature was 145. A polymerization mixture is obtained under reaction conditions of ℃, and this polymerization mixture is continuously fed into a devolatilization step consisting of a preheater and a vacuum tank connected in series with the reactor, and then granulated to form a PMS-based polymer. A composition was obtained. The temperature of the preheater was 250°C, the vacuum degree of the vacuum chamber was 1 Q torr, and the external temperature of the vacuum chamber was 260°C. The discharge bomb f from the vacuum chamber was operated so that the average residence time of the PMS polymer in the vacuum chamber was between 15 seconds and 1 minute. The composition of the PMS mixture used was 97
1-methyl-4-ethynylbenzene and 3% 1-
Methyl-3-17=/l/benzene.

1 Evaluation of molded product appearance: (1) Molding: The obtained PMS polymer composition was heated at 230°C.
injection molded. The molded object was a disk with a diameter of 180 mm and a thickness of 2 mm, with a bindard in the center of the circle.

(2) Appearance evaluation: The length 1) of all the linear patterns generated on the surface of the molded article was measured, and the extent to which the appearance was impaired was expressed as the sum of the lengths. It is determined that the larger the total value is, the worse the appearance is. The complete results are shown in Table 1.

C. Analysis: The amount of solvent-insoluble components was measured using tetrahydrofuran. Further, the amount of 1-methyl-4-ethynylbenzene was measured by gas chromatography.

Reference Example 1 Example IKI - The raw material supplied to the stirred tank reactor was changed to styrene, the average residence time was 4 hours in total, the polymerization temperature was 130°C, and the average residence time of the styrene polymer in the vacuum chamber was A polymer composition was produced and evaluated in the same manner as in Example 1, except that the evacuation pump from the vacuum chamber was operated so that the reaction time was 15 minutes to 1 hour. The results are shown in Table 1.

Comparative Example 1 In Reference Example 1, the raw material supplied to the stirred tank reactor was
MS mixture (manufactured by Mobil Oil, equivalent to Example 1)
A polymer composition was produced and evaluated in the same manner as in Reference Example 1, except for the following. The results are shown in Table 1.

Comparative Example 2 In Comparative Example 1, the procedure was the same as in Comparative Example 1, except that the discharge pump from the vacuum chamber was operated so that the average residence time of the PMS polymer in the vacuum chamber was 1 minute to 25 minutes. , a polymer composition was produced and evaluated.

The results are shown in Table 1.

Example 2 The polymer was produced in the same manner as in Example 1, except that the raw materials supplied to the stirred tank reactor had a composition of 60 parts by weight of styrene and 40 parts by weight of PMs mixture, and a total of 100 parts by weight was supplied. A composition was manufactured and evaluated. The results are shown in Table 1.

Step 1 A stirred tank reactor was continuously charged with 65 parts by weight of a PMS mixture (equivalent to that used in Example 1), 35 parts by weight of acrylonitrile, 7 parts by weight of ethylbenzene, and 0.2 parts by weight of t-dodecylmercaptan. The raw material liquid was supplied (an average residence time of 1 hour and a polymerization temperature of 145°C) to obtain a polymerization mixture, which was further passed through a devolatilization process consisting of a preheater and a vacuum tank connected in series with the reactor, and then passed through a volatilizer. After that, it was granulated to obtain a PMS polymer composition.The temperature of the preheater was 275°C, the vacuum degree of the vacuum chamber was 30 torr, and the external temperature of the vacuum chamber was 265°C.
The average residence time of the PMS polymer in the vacuum chamber is 1.
The discharge bomb f from the vacuum chamber was operated so that the time was between 1 and 3 minutes.

b. Evaluation and analysis: The same method as in Example 1 was used. The results are shown in Table 2.

Evaluation of Picat softening point: Measured according to ASTM D 1525.

Reference Example 2 A polymer composition was produced and evaluated in the same manner as in Example 3, except that the raw material PMS mixture in Example 3 was replaced with styrene. The results are shown in Table 2.

Dotogo-1 In Example 3, the same as Example 3 except that the discharge pump from the vacuum chamber was operated so that the average residence time of the PMS polymer in the vacuum chamber was between 30 and 45 minutes. A polymer composition was produced and evaluated.

The results are shown in Table 2.

Claims (4)

[Claims] (1) 0 to 1% by weight of 1-methyl-2-ethynylbenzene, 0 to 15% by weight of 1-methyl-3-ethynylbenzene, a little less than 85% by weight - methyl-4-ethynylbenzene In the production of a transparent molding polymer composition, the composition comprises a polymer comprising at least 30% by weight of a monomer mixture of The weight of the components insoluble in tetrahydrofuran in the composition is reduced to 0.00% of the composition.
1. A method for producing a transparent molding polymer composition, characterized in that the weight is adjusted to 0.05 to 0.010% by weight. (2) in a molding polymer composition obtained by a continuous bulk or solution polymerization method using at least a devolatilization device consisting of one or more heaters and a vacuum chamber connected to one or more reactors; 2. The method according to claim 1, wherein the amount of 1-methyl-4-ethynylbenzene remaining in the composition is adjusted to less than 0.3% by weight of the composition. (3) The polymer is O to 0.1% by weight of 1-methyl-2
- ethynylbenzene, 0 to 15% by weight of 1-methyl-3-ethynylbenzene and at least 485% (7% by weight) of 1-methyl-3-ethynylbenzene;
) 1-, , 'The method for producing a polymer of a monomer mixture consisting of 4-ethynylbenzene. (4) The copolymerizable monomer is acrylonitrile, methyl methacrylate, methacrylic acid, maleic anhydride,
The manufacturing method according to claim 1 or 2, wherein one or more types selected from styrene, α-methylstyrene, and bromustyrene are used.