JPS60197706A - Vinyl chloride resin of excellent extrudability - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vinyl chloride resin having particularly excellent extrusion productivity. More specifically, when producing pipes, corrugated plates, sheets, films, pellets for secondary molding, etc. by extrusion processing, the average particle size is 150 am or more,
The void volume at 31 to 1011 psl is 0.15 CC
The present invention relates to a vinyl chloride resin that has significantly improved extrusion productivity without deteriorating quality such as mechanical properties by using a vinyl chloride resin that has a molecular weight of /SF or more.

[Prior Art] Vinyl chloride resin is inexpensive and has excellent various mechanical properties, so it is used in large quantities in the fields of hard, semi-hard, and soft resins. In addition, various processing methods have been developed including extrusion molding, injection molding, blow molding, and calendar molding.

However, in recent years, from the viewpoint of energy conservation, a so-called cold blend method has been adopted in which the temperature is lower than before when producing vinyl chloride compounds. For this reason, the bulk specific gravity of the compound is lower than that in the conventional hot blending method, and the problem has become apparent that the ejection teeth in extrusion molding are significantly reduced, and the productivity of extrusion processing is extremely reduced.

Conventionally, in order to improve the productivity of extrusion processing, techniques to increase the bulk specific gravity of vinyl chloride resin and techniques to increase the bulk specific gravity of vinyl chloride resin have been developed, as described in Japanese Patent Application Laid-Open No. 51-21671 and Japanese Patent Publication No. 51-21670. As described in Japanese Patent No. 5G-26519, a technique for improving the fluidity of powder is known. However, simply increasing the bulk specific gravity increases the discharge rate and improves the extrusion productivity, but the physical properties, particularly elongation, Charpy impact strength, etc., decrease, making it impractical. Furthermore, as described in JP-A No. 52-5399, a technique using a special dispersant for the purpose of improving powder fluidity, and as described in JP-B No. 52-32770, A technique is disclosed in which oxyethylene sorbitan monoalkyl ester is added during polymerization. However, such techniques have drawbacks such as insufficient improvement in powder fluidity and loss of thermal stability of the vinyl chloride resin.

[Purpose of the Invention] In view of the above-mentioned circumstances, the present inventors have made extensive studies on the relationship between the powder properties of vinyl chloride resin and extrusion productivity in order to improve the extrusion productivity of vinyl chloride resin. , completed the invention.

[Structure of the Invention] That is, the present invention has an average particle diameter of 150 μm or more and a void volume of 0.15 in 31 to 1011 DSi.
The present invention relates to a vinyl chloride resin with excellent extrusion productivity characterized by a CC/9 or higher.

In addition, the average particle diameter mentioned in the specification is 42 mesh, 60 mesh
The values are calculated from cumulative distribution in accordance with JIS Z 8801 using standard sieves of mesh, 80 mesh, 100 mesh, 12G mesh, 150 mesh, and 20G mesh. Further, the void Fim of 31 to 1011 pSi is a value calculated by using a mercury intrusion porosimeter to determine the total volume of voids existing in the vinyl chloride resin having an average diameter of 5.9 to 0.177a at 31 to 1011 psi.

[Practicing the invention 111! ] The vinyl chloride resin referred to in this specification is a resin containing 60% by weight or more of vinyl chloride monomer units in the resin component, and includes, for example, polyvinyl chloride, vinyl chloride-ethylene copolymer, vinyl chloride loop 0 pyrene. Copolymers of vinyl chloride and olefins such as copolymers, vinyl chloride
Copolymers of vinyl chloride and vinyl esters such as vinyl acetate copolymers, vinyl chloride-vinyl stearate copolymers, copolymers of vinyl chloride and vinyl ethers such as vinyl chloride-methyl vinyl ether, vinyl chloride- Butyl acrylate copolymer, copolymer of vinyl chloride and acrylic acid ester such as vinyl chloride-ethyl acrylate copolymer, vinyl chloride-methyl methacrylate-1-copolymer, vinyl chloride-ethyl methacrylate copolymer, etc. This concept includes copolymers of vinyl chloride and methacrylic acid ester.

The flat particle diameter of the vinyl chloride resin used in this specification is 150
1. Limited to tm or more. If the average particle diameter is less than 150 μm, extrusion productivity decreases, which is not preferable. However, when increasing the average particle size, abnormal polymerization tends to occur in suspension polymerization, so the average particle size is preferably 150 to 250 μm.

The void volume of the vinyl chloride resin of the present invention at 31 to 1011 psi is limited to 0.15 CC/9 or more. If the amount of voids is less than 0.15 CC/9, the gelling properties of the vinyl chloride resin will deteriorate, resulting in deterioration of physical properties, which is not preferable. The void volume is 0.19 CC/9 or more and the bulk specific gravity is 0.
．． 54 /cc or more, in addition to the extrusion productivity improvement effect based on the average particle diameter, the extrusion processing productivity improvement effect based on bulk specific gravity can be added, and the physical properties of the molded product are the same as conventional products. This is particularly desirable since it has the effect of maintaining physical properties.

It is not clear why extrusion productivity is significantly improved when using the vinyl chloride resin of the present invention, but the larger average particle size improves powder fluidity and allows for more particles to be filled into the extruder per unit time. This is thought to be due to an increase in the amount of resin used.

The vinyl chloride resin of the present invention is preferably produced by suspension polymerization. That is, it can be obtained by adding a dispersant, an initiator, and other additives to an aqueous medium, then deaerating the air, adding a predetermined amount of vinyl chloride, and polymerizing it at a predetermined temperature.

There are no particular limitations on the dispersant used at this time, but it is preferable to use partially saponified polyvinyl acetate, and the degree of saponification is 6.
It is preferably 5 to 90%.

There are no particular limitations on the initiator used, but diisopropyl peroxydicarbonate, 2-ethylhexyl peroxydicarbonate, azobisisobutyronitrile, 2,2°-azobis-2,4-dimethylvaleronitrile, etc. It is preferable to use the following. Other additives such as dispersion aids, antioxidants, polymerization stabilization aids, chain transfer agents, and scale inhibitors can be freely added depending on the purpose. Further, a small amount of a monomer copolymerizable with vinyl chloride, such as ethylene, propylene, vinyl acetate, butyl acrylate, etc., may be added to vinyl chloride for polymerization.

The vinyl chloride resin of the present invention contains 100 parts of vinyl chloride resin (
It is used in the semi-rigid or rigid extrusion field where the plasticizer is used in an amount of 60 parts by weight or less. That is, stabilizers, lubricants,
It is preferable to mix additives such as fillers, pigments, processing aids, and blowing agents, or ordinary vinyl chloride resins other than the vinyl chloride resin of the present invention, and use the mixture by cold blending at a temperature of 80°C or lower. However, when hot-blended, the effect of increasing extrusion productivity is reduced, but it goes without saying that it shows better extrusion productivity than conventional vinyl chloride resins.

The vinyl chloride resin of the present invention is used in the extrusion field, and when using a twin-screw type extruder such as a twin-screw extruder in the same direction, a twin-screw extruder in different directions, or a conical extruder, it can be used in the extrusion field. When the discharge volume per unit time is large, such as when the discharge volume is large, or when the discharge volume per unit time is large, such as under processing conditions where the screw rotation speed is high, the effect of improving extrusion processing productivity is remarkable.

In the above explanation, the main purpose of the vinyl chloride resin of the present invention, which is to improve the extrusion productivity, that is, the amount of resin extruded per unit time, has been mainly described, but another advantage is that it does not suffer from static electricity. It has advantages such as being easy to handle due to less dust, and increasing the filling speed when filling bags due to improved powder fluidity.

The present invention has been developed because conventionally, when the average particle size is large, the gelling property is poor and the physical properties of extruded products such as pipes, sheets, and films are significantly deteriorated.
) PVC resin with an average particle diameter of 150 μm or more, which has been discarded due to remaining particles, has been improved by making it have a void volume of 0.15 CC/9 or more, and has significantly improved extrusion productivity. It is based on the discovery that it improves.

Next, the vinyl chloride resin of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 In a 200J stainless steel polymerization vessel equipped with a stirrer, 120 parts of ion-exchanged water and polyvinyl acetate with a partial saponification degree of 78% were added.
．． 04 parts, 2-ethylhexyl peroxydicarbonate 0.04 parts, azobisisobutyronitrile 0.006 parts
and 0.003 parts of thioacetic acid, and the inside of the can was heated to 20.0 parts. NQ
After degassing until the temperature was 100%, 100 parts of vinyl chloride monomer was charged, and the temperature was raised to 56.5° C. while stirring to initiate polymerization. The pressure inside the can is from constant pressure to 'IK9/a! - When G dropped, cooling was started, and at the same time, unreacted upper trash was collected. The obtained slurry was dehydrated and dried to obtain a vinyl chloride resin having the properties shown in Table 3.

After blending the obtained resin according to the formulation shown in Table 1, it was stirred at low speed using a 300J Henschel mixer, and when the resin temperature reached 50 ° C., the contents were discharged.
The compound was made into a Vl'-75 pipe under the extrusion conditions shown in Table 2 using a twin-screw extruder with a diameter of 8G in different directions, and the extrusion productivity was evaluated. .

The results are shown in Table 3.

Using the obtained VP-75 pipe, the physical properties of the molded product were measured by the following method. The results are shown in Table 3.

(Tensile strength and elongation rate) A test piece was cut from a VP-75 pipe in accordance with JIS 6721 at a test temperature of 23°C and a tensile rate of 10.
Measured in am/min.

(Charpy impact strength) A JIS No. I test piece was cut from a JIS K 7111GC compliant LrVP-75 tube and measured at 23°C. Note that the notch was a ■ notch with R=0.75 am.

Note that the characteristic values of each vinyl chloride resin were measured by the following measuring method.

(Average particle size) Standard sieves specified in JIS Z a801 (42 mesh, 60 mesh, 8G mesh, 100 mesh, 1
20 meshes, 150 meshes, 200 meshes) and measured from the cumulative curve.

(Amount of air gap) Using a "Porosimeter" made by Aminco Co., Ltd., accurately weigh out 0.29 of vinyl chloride resin, place it in the Benestrometer, and set the Benestrometer in the decompression unit. After reducing the pressure to below ITorr and returning it to atmospheric pressure, the Benestrometer is simultaneously filled with mercury to fill the spaces between the vinyl chloride resin particles with mercury. After that, set the Benestrometer in a pressurizing unit filled with isopropanol, and gradually apply pressure to find the relationship between the scale of the Benestrometer and the pressure, and estimate the air gap between 31 and 1011 psi. , 1g of vinyl chloride 1! Converted per Ill and expressed as CC/9.

(Bulk specific gravity) Based on JIS K 6721, bulk specific gravity was measured using a Toyo Seiki bulk specific gravity meter and expressed as 9/100CC.

(Viscosity average degree of polymerization) Measured in accordance with JIS 6721.

In addition, extrusion productivity was evaluated as follows.

(Extrusion productivity) When pipe forming is performed, measure the weight of the pipe extruded in 5 minutes, multiply this by 12 to find the discharge volume per hour, and calculate this discharge volume as the extrusion productivity. displayed as a parameter.

Table 2 Example 2 O and ooa parts of thioacetic acid were added to 0.0 and 2-mercaptoethanol.
The third part was prepared in the same manner as in Example 1 except that it was changed to part 003.
A vinyl chloride resin having the properties shown in the table was obtained. Using the obtained resin, extrusion productivity and molded product properties were measured in the same manner as in Example 1. The results are shown in Table 3.

Example 3 A vinyl chloride resin having the properties shown in Table 3 was obtained in the same manner as in Example 2, except that the amount of 2-mercaptoethanol added was changed to 0.0035 parts.

Using the obtained resin, extrusion productivity and molded product physical properties were measured in the same manner as in Example 1. Those results in the third
Shown in the table.

Example 4 A vinyl chloride resin having the properties shown in Table 3 was obtained in the same manner as in Example 2, except that the amount of 2-mercaptoethanol added was changed to 0.0045 parts.

Using the obtained resin, extrusion productivity and molded product physical properties were measured in the same manner as in Example 1. Those results in the third
Shown in the table.

Example 5 Polymerization was started in the same manner as in Example 2, and after reaching the predetermined temperature, 4
．． At the time of 5 hours, the mixture was cooled and the monomer was recovered, and the same procedure as in Example 2 was carried out to obtain a vinyl chloride resin having the properties shown in Table 3. Using the obtained resin, extrusion productivity and molded product physical properties were measured in the same manner as in Example 1. The results are shown in Table 3.

Example 6 Polymerization was started in the same manner as in Example 2, and after reaching the predetermined temperature, 4
．． At the time of 5 hours, 10 parts of vinyl chloride resin monomer was further added, and the same procedure as in Example 2 was carried out to obtain a vinyl chloride resin having the properties shown in Table 3. Using the obtained resin, extrusion productivity and molded product physical properties were measured in the same manner as in Example 1. The results are shown in Table 3.

Example 7 The same procedure was carried out as in Example 1, except that the amount of partially saponified polyvinyl acetate with a saponification degree of 78°C was changed to 0.02 part, and 0.02 part of partially saponified polyvinyl acetate with a saponification degree of 90% was added. Polymerization was carried out in the same manner as in Example 1 to obtain a vinyl chloride resin having the properties shown in Table 3. Using the obtained resin, extrusion productivity and molded product physical properties were measured in the same manner as in Example 1. The results are shown in Table 3.

Comparative Example 1 A vinyl chloride resin having the properties shown in Table 3 was obtained in the same manner as in Example 1 except that 0.003 part of thioacetic acid was not used. Using the obtained resin, extrusion productivity and molded product physical properties were measured in the same manner as in Example 1i. The results are shown in Table 3.

Comparative Example 2 Polymerization was started in the same manner as in Example 3, and after reaching the predetermined temperature, 4
When 65 hours had elapsed, 30 parts of a vinyl chloride resin top layer was added, and the same procedure as in Example 3 was carried out to obtain a vinyl chloride resin having the properties shown in Table 3. Using the obtained resin, extrusion productivity and molded product physical properties were measured in the same manner as in Example 1. The results are shown in Table 3.

The following can be seen from Table 3.

(1) As shown in Comparative Example 1, the average particle diameter is 150 μm
If a vinyl chloride resin with a void volume of 0.15 cc/9 or more (0.21 cc/9) is used, the physical properties of the molded product will be good, but the extrusion productivity will be significantly inferior.

(2) As shown in Comparative Example 2, the average particle diameter is 150 μm
Above (171111FL), the void volume is 0.15CC/9
When a vinyl chloride resin of less than 0.14 cc/9 is used, the extrusion productivity is good, but the physical properties of the molded product are significantly inferior.

(3) As shown in Examples 1 to 7, the average particle diameter is 150
More than μm (162 to 210μTrL) and void amount is 0.1
When a vinyl chloride resin of 5CC/9 or more (0.18 to 0.31 cc/g) is used, the physical properties of the molded product and the productivity of extrusion processing will be good. That is, the extrusion productivity is significantly superior to Comparative Example 1, and the physical properties of the molded product are significantly superior to Comparative Example 2.

(4) As shown in Examples 1 to 4, the average particle diameter is 150
More than μm (162 to 210μm), the void is 0.19C
C/g or more (0.21-0.23cc/9),
and has a bulk specific gravity of 0.54 CC/9 or more (0,554 to 0
．． When a vinyl chloride resin of 562 cc/9) is used, both the extrusion productivity and the physical properties of the molded product are at a high level and are well-balanced.

Example 8 The vinyl chloride resin obtained in Example 1 was blended with the composition shown in Table 4, stirred at high speed using a 300 J Henschel mixer, and when the resin temperature reached 130°C, the contents were The mixture was transferred to a cooling mixer and cooled to a resin temperature of 50° C. to obtain a resin composition.

The obtained resin composition was molded into a T-die sheet with a thickness of 0.5 cm under the extrusion conditions shown in Table 5, and the physical properties of the sheet were measured by the following method. In addition, extrusion productivity during molding was measured. The results are shown in Table 6.

(Tensile strength and elongation rate) The obtained T-die sheet with a thickness of 0.5 am was heated and press-formed at 185°C for 15 minutes to obtain a press sheet with a thickness of 1.2 mm, which was then punched into JIS dumbbells and measured. Measured at a temperature of 23°C and a tensile rate of 10agt/min.

(Charpy impact strength) The obtained T-die sheet with a thickness of 0.5 ml was heated to 185°C.
A press plate with a thickness of 5111 was obtained by hot press molding for 15 minutes, and a test piece was cut according to JIS 1111 and measured at 23°C. Note that Notsuchi is R-
The V-notch was 0.75a+m.

In addition, extrusion productivity was evaluated as follows.

(Extrusion productivity) ■Measure the weight of the sheet extruded in 5 minutes during die sheet molding, multiply this by 12 to get the discharge volume per hour, and use this discharge volume as the extrusion productivity parameter. Displayed as.

Table 4 Table 5 The polyethylene wax (617A) in Table 4 is low molecular weight polyethylene manufactured by Allied Chemical Co., Ltd., and the HBS resin (B-22) is manufactured by Kane Ace 8-2 manufactured by Kanefuchi Chemical Industry ■-.
2. The processing aid (P^-20) is Kane Ace PA-20 manufactured by Kanebuchi Chemical Industry ■.

Examples 9 to 14 and Comparative Examples 3 to 4 Using the vinyl chloride resins obtained in Examples 2 to 7 and Comparative Example 12, ■Die sheets were formed in the same manner as in Example 8, and extrusion productivity and sheet Physical properties were measured. The results are shown in Table 6.

The following can be seen from Table 6.

(1) As shown in Comparative Example 3, the average particle diameter is 156 μm
If a vinyl chloride resin with a void volume of 0.15 cc/IJ or more (0.21 cc/9) is used, the physical properties of the sheet molded product will be good, but the extrusion productivity will be significantly inferior.

(2) As shown in Comparative Example 4, the average particle diameter is 150 um
When using a vinyl chloride resin with a void volume of less than 0.15 cc/9 (0.14 cc/9) and above (176 μm),
Extrusion productivity is good, but sheet properties are significantly inferior.

(3) As shown in Examples 8 to 14, the average particle diameter is 15
0 tln or more (162 to 210 μm) and the void volume is 0.1
5CC/9 or more (0,18~G, 31 CC/9)
When using vinyl chloride resin, the sheet properties and extrusion productivity will be good. That is, the extrusion productivity is far superior to Comparative Example 3, and the sheet properties are far superior to Comparative Example 4.

(4) As shown in Examples 8 to 11, the average particle diameter is 15
0μm or more (162-210um) and void volume is 0.19
cc/g or more (0.21-0.23cc/9),
and has a bulk specific gravity of 0.549/CC or more (0.554 to 0.
When a vinyl chloride resin of 5629/cc) is used, both extrusion productivity and sheet physical properties are at a high level and are well balanced.

[Effects of the Invention] By using the vinyl chloride resin of the present invention, even when using a compound blended by the cold blending method, extrusion is possible while maintaining the physical properties of the molded product as conventionally (obtained by the hot blending method). A remarkable effect can be obtained in that processing productivity can be greatly improved.

Patent applicant: A-Fuchi Chemical Industry Co., Ltd.

Claims (1)

[Scope of Claims] 1. The average particle diameter is 150 μm or more, and 31 to 1
A vinyl chloride resin with excellent extrusion productivity characterized by a void volume of 0.15 CC/9 or more at 0.011 psi. 2. Claim 1, wherein the void volume is 0.19 CC/g or more and the bulk specific gravity is 0.549/CC or more.
Vinyl chloride resin with excellent extrusion productivity as described in Section 1.