Method for producing resin composition

Abstract

To easily produce a soft polyvinyl chloride resin composition by recycling a resin shape material mainly composed of a hard polyvinyl chloride.SOLUTION: In a method for producing a resin composition, a resin composition of a soft polyvinyl chloride is produced by using a resin shape material mainly composed of a hard polyvinyl chloride as a raw material. The method for producing the resin composition includes: a pulverizing step of pulverizing the resin shape material to form a pulverized material; a kneading step of kneading a master batch compound prepared by compounding a hard polyvinyl chloride, a stabilizer and a plasticizer, a powder material containing calcium carbonate as a main component, and the pulverized material while heating them to obtain a kneaded material; and a mixing step of kneading the kneaded material and the master batch compound while heating them to produce a resin composition in which the kneaded material and the master batch compound are mixed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing a resin composition for producing a flexible polyvinyl chloride resin composition. [Background technology]

[0002] Resin shaped materials mainly composed of rigid polyvinyl chloride are used in fittings such as resin windows. The resin shaped materials are produced by heating and melting the rigid polyvinyl chloride resin material, and extruding the molten resin material. When recycling such resin shaped materials to produce a flexible polyvinyl chloride resin composition, for example, the resin shaped materials are crushed and mixed with a liquid plasticizer, and the crushed rigid polyvinyl chloride material is softened by the plasticizer to produce a flexible polyvinyl chloride resin composition.

[0003] However, in the resin shaped material after production, the resin particles are crushed by extrusion molding, and the voids in the resin particles that existed before extrusion molding are almost eliminated. Accordingly, during kneading of the crushed material of the resin shaped material and the plasticizer, the plasticizer is less likely to penetrate into the crushed material, and the crushed materials are more likely to slide against each other due to the plasticizer. Therefore, the crushed material of the resin shaped material and the plasticizer are less likely to be kneaded, and it is difficult to soften the rigid polyvinyl chloride of the crushed material with the plasticizer. In response to this, a method for producing a flexible vinyl chloride resin composition has been known in the past, in which a crushed product having a particle size of 3 mm or less obtained by crushing a rigid vinyl chloride resin molded product, a plasticizer, and a filler are mixed in a mixer to produce a flexible vinyl chloride resin composition (see Patent Document 1).

[0004] In the conventional method for producing a flexible vinyl chloride resin composition described in Patent Document 1, the plasticizer is absorbed by the filler, and the plasticizer is mixed with the pulverized material together with the filler. However, since the plasticizer is mainly mixed with the pulverized material in an amount absorbed by the filler, the amount of plasticizer to be added is limited, which may make it difficult to produce a flexible vinyl chloride resin composition. In addition, since the amount of plasticizer to be added depends on the type of filler, etc., the design of the flexible vinyl chloride resin composition may be limited. Therefore, the conventional method for producing a flexible vinyl chloride resin composition has room for improvement from the viewpoint of easily producing a flexible vinyl chloride resin composition. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5446105 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above-mentioned problems in the conventional art, and an object of the present invention is to easily produce a resin composition of soft polyvinyl chloride by recycling a resin shape mainly composed of hard polyvinyl chloride. [Means for solving the problem]

[0007] The present invention relates to A method for producing a resin composition, comprising the steps of: producing a flexible polyvinyl chloride resin composition using a resin shape material mainly composed of rigid polyvinyl chloride as a raw material, the method comprising the steps of: A crushing step of crushing the resin shaped material to form a crushed material; A kneading step of kneading a master batch mixture containing rigid polyvinyl chloride, a stabilizer, and a plasticizer, a powder material containing calcium carbonate as a main component, and the pulverized material while heating them to obtain a kneaded mixture; a mixing step of kneading the kneaded material and the master batch compound while heating to produce the resin composition in which the kneaded material and the master batch compound are mixed; The present invention relates to a method for producing a resin composition having the above structure. Effect of the Invention

[0008] According to the present invention, a resin composition of flexible polyvinyl chloride can be easily produced by recycling a resin shape material mainly composed of rigid polyvinyl chloride. [Brief description of the drawings]

[0009] [Figure 1] 1 is a flowchart showing a procedure for producing a soft polyvinyl chloride resin composition of the present embodiment. [Diagram 2] FIG. 2 is a diagram showing a schematic diagram of each stage of the manufacturing process of the soft polyvinyl chloride resin composition of the present embodiment. [Diagram 3] 1A to 1C are diagrams showing examples of pulverized materials used to generate a kneaded product according to the present embodiment. [Figure 4] 11A and 11B are diagrams illustrating another example of the resin shaped material of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment of the method for producing a resin composition of the present invention will be described with reference to the drawings. In the method for producing a resin composition according to the present embodiment, a resin material mainly composed of rigid polyvinyl chloride is used as a raw material to produce a flexible polyvinyl chloride resin composition. This allows the resin material once produced to be reused, recycled into a resin composition, and a new resin composition is produced.

[0011] Fig. 1 is a flow chart showing the procedure (steps) for producing a flexible polyvinyl chloride resin composition of this embodiment. Fig. 2 is a diagram showing the state of each stage of the process for producing a flexible polyvinyl chloride resin composition of this embodiment.

[0012] As shown in the figure, unnecessary resin shaped material 10 (see FIG. 2A) is collected (S101 in FIG. 1). The resin shaped material 10 is a material (extruded material) formed by extrusion molding of resin. The resin is rigid polyvinyl chloride, and the resin shaped material 10 is a rigid polyvinyl chloride shaped material made of rigid polyvinyl chloride. Rigid polyvinyl chloride is polyvinyl chloride (PVC) without a plasticizer mixed therein, and other components (for example, various stabilizers and improvers) may be mixed into the polyvinyl chloride. Note that FIG. 2A shows a cross section perpendicular to the longitudinal direction of the resin shaped material 10.

[0013] Here, the resin shaped material 10 is a resin molded product (resin molded product) used for a resin window, which is a fixture. A resin window has a resin frame (resin frame) and a paper screen including a resin stile (resin frame), and the resin frame and the resin stile are each made of the resin shaped material 10. In addition, scraps of the resin shaped material 10 for the resin window are collected as the resin shaped material 10. The scraps of the resin shaped material 10 are, for example, scraps at a manufacturing site for the resin window or scraps collected as market scraps. In contrast, the resin shaped material 10 may be discarded resin shaped material 10.

[0014] Next, the collected resin shaped material 10 is crushed by a crusher to form crushed material 20 of the resin shaped material 10 (see FIG. 2B) (S102 in FIG. 1). The crusher is, for example, an impact crusher, which is an impact type crusher. When the resin shaped material 10 is long or large, the resin shaped material 10 is cut or otherwise formed into a size that can be crushed by the crusher before crushing by the crusher. The resin shaped material 10 may be crushed in two stages. In this case, the resin shaped material 10 is coarsely crushed by a crusher for coarse crushing in the first stage, and then the coarsely crushed material 20 is crushed into finely crushed material 20 by a crusher for fine crushing in the second stage. In this way, the crushed material 20 is generated by crushing the resin shaped material 10.

[0015] The resin profile 10 is a part of the raw material of the resin composition of soft polyvinyl chloride. Soft polyvinyl chloride is polyvinyl chloride mixed with a plasticizer, and contains the plasticizer. The resin composition is a composition whose main component is soft polyvinyl chloride, and is the raw material for molded products of soft polyvinyl chloride. The plasticizer is an additive that gives flexibility to hard polyvinyl chloride, and softens it.

[0016] Examples of the plasticizer include phthalate ester plasticizers such as dibutyl phthalate (DBP), diisodecyl phthalate (DIDP), bis(2-ethylhexyl) phthalate (DOP), butyl benzyl phthalate (BBP), and diisononyl phthalate (DINP); aliphatic dibasic acid ester plasticizers such as tris(2-ethylhexyl) trimellitate (TOTM), bis(2-ethylhexyl) adipate (DOA), diisononyl adipate (DINA), diisodecyl adipate (DIDA), and dibutyl sebacate (DBS); phosphate ester plasticizers such as tris(2-ethylhexyl) phosphate (TOP) and triphenyl phosphate (TPP); and plasticizers such as polyesters and epoxidized soybean oil.

[0017] Before manufacturing a resin composition of soft polyvinyl chloride using the pulverized material 20 of the resin shaped material 10 as a raw material (see FIG. 2C), a powder material mainly composed of hard polyvinyl chloride (first powder material 30), a powder material composed of a stabilizer (second powder material 40), and a liquid plasticizer 50 are kneaded by a mixer. As a result, the first powder material 30, the second powder material 40, and the plasticizer 50 are mixed to generate a master batch compound 60 (see FIG. 2D) composed of the first powder material 30, the second powder material 40, and the plasticizer 50 (S103 in FIG. 1). The mixer is, for example, a ribbon blender having ribbon-shaped blades, and the first powder material 30, the second powder material 40, and the plasticizer 50 are mixed by the rotating blades.

[0018] The first powder material 30 is a powder of hard polyvinyl chloride (hard polyvinyl chloride powder) formed into a powder form, and is a powder (fine powder) smaller than the crushed material 20. The first powder material 30 is an unused hard polyvinyl chloride powder or a recycled hard polyvinyl chloride powder. When using recycled hard polyvinyl chloride powder as the first powder material 30, the resin shaped material 10 is crushed by a crusher until it becomes a powder smaller than the crushed material 20, and hard polyvinyl chloride powder (first powder material 30) is generated by crushing the resin shaped material 10. In this way, the first powder material 30 is formed from the resin shaped material 10.

[0019] The second powder material 40 is a stabilizer powder (stabilizer powder) formed into a powder form, and is a powder (fine powder) smaller than the pulverized material 20. The stabilizer is, for example, a thermal stabilizer that suppresses thermal decomposition of a resin composition of soft polyvinyl chloride, and stabilizes the resin composition to suppress deterioration of the resin composition. In addition, the stabilizer is, for example, a barium-zinc-based (Ba-Zn-based) stabilizer, a calcium-zinc-based (Ca-Zn-based) stabilizer, or a tin-based (Sn-based) stabilizer.

[0020] The particle size of the first powder material 30 and the particle size of the second powder material 40 are each 500 μm or less. Here, the particle size is a particle size sieved using a sieve with a nominal mesh size conforming to the Japanese Industrial Standards (JIS Z 8801-1:2019), and a particle size of 500 μm or less refers to a particle size that passes through a sieve with a nominal mesh size of 500 μm. The first powder material 30 and the second powder material 40 with a particle size of 500 μm or less are mixed with a plasticizer 50 to generate a master batch compound 60 in which the first powder material 30, the second powder material 40, and the plasticizer 50 are compounded.

[0021] When the master batch compound 60 is produced, the rigid polyvinyl chloride and the stabilizer are each in the form of powder (the first powder material 30, the second powder material 40), so that the rigid polyvinyl chloride and the stabilizer are efficiently mixed. Also, the plasticizer 50 is easily absorbed into the first powder material 30, so that the plasticizer 50 is efficiently mixed into the first powder material 30. While the plasticizer 50 is absorbed into the first powder material 30, the first powder material 30, the second powder material 40, and the plasticizer 50 are thoroughly mixed.

[0022] The master batch compound 60 is a compound in which a specific component among the components contained in the resin composition of soft polyvinyl chloride is compounded at a higher concentration than the concentration (target concentration) in the resin composition. Here, the master batch compound 60 contains hard polyvinyl chloride contained in the first powder material 30, the stabilizer contained in the second powder material 40, and the plasticizer 50, and contains the plasticizer 50 at a higher concentration than the target concentration. In this way, the master batch compound 60 is a compound in which hard polyvinyl chloride, the stabilizer, and the plasticizer 50 are compounded, and the plasticizer 50 is compounded at a higher concentration than the target concentration.

[0023] In the master batch compound 60, when the first powder material 30 is 100 parts by weight (phr), the plasticizer 50 is 150 parts by weight or more and 250 parts by weight or less. In this way, 150 parts by weight or more and 250 parts by weight or less of the plasticizer 50 is added to 100 parts by weight of the first powder material 30, and the first powder material 30 of hard polyvinyl chloride, the second powder material 40 of the stabilizer, and the plasticizer 50 are blended to generate the master batch compound 60. At that time, the hard polyvinyl chloride contained in the first powder material 30, the stabilizer contained in the second powder material 40, and the plasticizer 50 are mixed (blended), and the hard polyvinyl chloride contained in the first powder material 30 is softened by the plasticizer 50, and a master batch compound 60 softer than a resin composition of soft polyvinyl chloride is generated. The master batch compound 60 after generation is a liquid (slurry) object with high viscosity and can be easily deformed.

[0024] Next (see FIG. 2E), the master batch compound 60, the powder material (third powder material 70) mainly composed of calcium carbonate, and the pulverized material 20 of the resin molded material 10 are heated and kneaded by a heating kneader (S104 in FIG. 1). As a result, the master batch compound 60, the third powder material 70, and the pulverized material 20 are mixed to obtain a kneaded material 80 (see FIG. 2F) in which the master batch compound 60, the third powder material 70, and the pulverized material 20 are kneaded. The heating kneader is, for example, a Banbury mixer, a kneader, or a Brabender, and applies a shear force to the master batch compound 60, the third powder material 70, the pulverized material 20, and the kneaded material 80 during kneading. The master batch compound 60, the third powder material 70, the pulverized material 20, and the kneaded material 80 are heated to a predetermined temperature and kneaded by the heating kneader.

[0025] The third powder material 70 is a powder of calcium carbonate (calcium carbonate powder) formed into a powder form, and is a powder (fine powder) smaller than the pulverized material 20. The particle size of the third powder material 70 is 500 μm or less, similar to the first powder material 30 and the second powder material 40. The third powder material 70 having a particle size of 500 μm or less is kneaded with the master batch compound 60 and the pulverized material 20 to generate a kneaded material 80 of the master batch compound 60, the third powder material 70, and the pulverized material 20.

[0026] FIG. 3 is a diagram showing an example of the pulverized material 20 used to generate the kneaded material 80 of this embodiment. As shown in the figure, the crushed material 20 of various shapes and maximum dimensions R is formed by crushing the resin shaped material 10. The maximum dimension R of the crushed material 20 is the dimension of the largest part of the outer shape of each crushed material 20. The maximum dimension R of the crushed material 20 used to generate the kneaded material 80 is 15 mm or less. Therefore, when crushing the resin shaped material 10, the resin shaped material 10 is crushed so that the maximum dimension R of the crushed material 20 is 15 mm or less. Alternatively, after crushing the resin shaped material 10, a separator or the like is used to separate and remove the crushed material 20 having a maximum dimension R greater than 15 mm, and the crushed material 20 having a maximum dimension R of 15 mm or less is selected. The crushed material 20 having a maximum dimension R of 15 mm or less is kneaded with the master batch compound 60 and the third powder material 70 to generate the kneaded material 80.

[0027] In the kneaded material 80, when the pulverized material 20 is 100 parts by weight, the master batch compound 60 is 30 parts by weight or more and 60 parts by weight or less, and the third powder material 70 is 5 parts by weight or more and 50 parts by weight or less. In this way, when generating the kneaded material 80, 30 parts by weight or more and 60 parts by weight or less of the master batch compound 60 is added to 100 parts by weight of the pulverized material 20, and 5 parts by weight or more and 50 parts by weight or less of the third powder material 70 is added. In addition, the master batch compound 60, the third powder material 70, and the pulverized material 20 are kneaded while heating the master batch compound 60, the third powder material 70, and the pulverized material 20 from the temperature at the start of kneading (for example, room temperature) to a temperature within the range of 160 ° C. or more and 190 ° C. or less by a heating kneader, and the kneading of the kneaded material 80 is completed.

[0028] When the kneaded material 80 is produced, the calcium carbonate contained in the third powder material 70 and the hard polyvinyl chloride contained in the pulverized material 20 are mixed with the master batch compound 60, which is polyvinyl chloride containing a stabilizer and a plasticizer 50. Since the master batch compound 60 and the pulverized material 20 are both polyvinyl chloride, they are compatible with each other and can be easily mixed (kneaded). Therefore, the plasticizer 50 contained in the master batch compound 60 is easily mixed with the pulverized material 20. By mixing the plasticizer 50 contained in the master batch compound 60 and the hard polyvinyl chloride contained in the pulverized material 20, the hard polyvinyl chloride contained in the pulverized material 20 is softened by the plasticizer 50, and soft polyvinyl chloride is produced.

[0029] The kneaded material 80 is an intermediate mixture obtained by mixing the master batch compound 60, the third powder material 70, and the pulverized material 20, and is generated in the intermediate stage of manufacturing the final mixture, which is a resin composition of soft polyvinyl chloride. The kneaded material 80 contains soft polyvinyl chloride as the main component, a stabilizer, calcium carbonate, and a plasticizer 50. The master batch compound 60, the third powder material 70, and the pulverized material 20 are thoroughly mixed to generate the kneaded material 80 of soft polyvinyl chloride containing the stabilizer and calcium carbonate.

[0030] When the master batch compound 60, the third powder material 70, and the pulverized material 20 are mixed (see FIG. 2G), the solid calcium carbonate 71 (e.g., calcium carbonate crystals) contained in the third powder material 70 bites into the pulverized material 20. In addition, the calcium carbonate 71 causes the pulverized material 20 to be caught by the master batch compound 60, and the pulverized materials 20 to be caught by each other. This increases the friction acting between the pulverized material 20 and the master batch compound 60, and the friction acting between the pulverized materials 20, making it easier for the pulverized material 20 and the master batch compound 60 to mix. As a result, the mixing of the pulverized material 20 and the master batch compound 60 is promoted. At the same time, since the calcium carbonate is a powder (the third powder material 70), the calcium carbonate is efficiently mixed into the master batch compound 60 and the kneaded material 80. Therefore, the kneaded material 80 is easily mixed.

[0031] After the kneading of the kneaded material 80 is completed, the kneaded material 80 of the master batch compound 60, the third powder material 70, and the pulverized material 20 is processed to form pellets 81 (see FIG. 2H) of the kneaded material 80 (S105 in FIG. 1). The pellets 81 are granular materials of the kneaded material 80 formed into granules, and contain soft polyvinyl chloride as the main component, a stabilizer, and calcium carbonate. The pellets 81 are formed from the kneaded material 80 by the forming process of the pellets 81.

[0032] In the molding process of the pellets 81, the kneaded material 80 in a molten state is discharged from the heat kneader and passed between rolls arranged in parallel. At that time, the kneaded material 80 is compressed by passing between the outer circumferential surfaces of two or more opposing rolls. Next, the kneaded material 80 is extruded by an extrusion molding machine, and the extruded kneaded material 80 is cut in sequence to mold the pellets 81 of the kneaded material 80.

[0033] Next, the kneaded material 80 and the master batch compound 60 are heated and kneaded by a heating kneader to produce a soft polyvinyl chloride resin composition in which the kneaded material 80 and the master batch compound 60 are mixed (S106 in FIG. 1). At that time, the pellets 81 of the kneaded material 80 and the master batch compound 60 are heated and kneaded to mix the pellets 81 and the master batch compound 60. The heating kneader applies a shear force to the kneaded material 80 (pellets 81), the master batch compound 60, and the resin composition during kneading. The kneaded material 80, the master batch compound 60, and the resin composition are heated to a predetermined temperature and kneaded by the heating kneader to produce a resin composition.

[0034] In the resin composition of soft polyvinyl chloride, when the kneaded material 80 (pellets 81) is 100 parts by weight, the master batch compound 60 is more than 0 parts by weight and not more than 100 parts by weight. In this way, when producing the resin composition, more than 0 parts by weight and not more than 100 parts by weight of the master batch compound 60 is added to 100 parts by weight of the kneaded material 80. In addition, the kneaded material 80, the master batch compound 60, and the resin composition are kneaded while heating the kneaded material 80 and the master batch compound 60 from the temperature at the start of kneading (for example, room temperature) to a temperature within a range of 120°C to 165°C by a heating kneader, and the kneading of the resin composition is completed.

[0035] When the resin composition of soft polyvinyl chloride is produced, each component contained in the kneaded material 80 is mixed with each component contained in the master batch compound 60. Since both the kneaded material 80 and the master batch compound 60 are polyvinyl chloride, they are compatible with each other and can be easily mixed (kneaded). In addition, the soft polyvinyl chloride contained in the kneaded material 80 is further softened by the plasticizer 50 contained in the master batch compound 60.

[0036] The resin composition of soft polyvinyl chloride is a final mixture of the kneaded material 80 (pellets 81) and the master batch compound 60. The resin composition contains soft polyvinyl chloride as a main component, a stabilizer, calcium carbonate, and a plasticizer 50. The kneaded material 80 and the master batch compound 60 are thoroughly mixed to produce a resin composition of soft polyvinyl chloride containing the stabilizer and calcium carbonate.

[0037] The hardness of the soft polyvinyl chloride resin composition varies depending on the concentration (for example, mass percent concentration) of the plasticizer 50 contained therein, and the hardness corresponds to the concentration of the plasticizer 50. The concentration of the plasticizer 50 contained in the soft polyvinyl chloride resin composition and the hardness of the resin composition are adjusted by adjusting the weight parts of the master batch compound 60 added to the pulverized material 20 and the weight parts of the master batch compound 60 added to the kneaded material 80 based on the weight parts of the plasticizer 50 contained in the master batch compound 60. The concentration of the plasticizer 50 contained in the resin composition is adjusted to a target concentration, and the hardness of the resin composition is adjusted to a target hardness.

[0038] After the production of the flexible polyvinyl chloride resin composition is completed, the molten resin composition is discharged from the heat kneader and passed between rolls arranged in parallel (S107 in FIG. 1). At that time, the resin composition is compressed by passing between the outer circumferential surfaces of two or more opposing rolls. Next, the resin composition is extruded by an extrusion molding machine, and the extruded resin composition is cut in sequence to form flexible polyvinyl chloride pellets (S108 in FIG. 1). Then, the flexible polyvinyl chloride pellets are used to form flexible polyvinyl chloride molded products (S109 in FIG. 1). Flexible polyvinyl chloride molded products are, for example, airtight materials and gaskets used in building fixtures.

[0039] When the master batch compound 60, the third powder material 70, and the pulverized material 20 are mixed in one kneading to produce a soft polyvinyl chloride resin composition, the total amount of the plasticizer 50 contained in the master batch compound 60 mixed at one time increases. Accordingly, the amount of the plasticizer 50 mixed with the pulverized material 20 increases, and the plasticizer 50 becomes difficult to mix with the pulverized material 20. In addition, the viscosity of the mixture consisting of the master batch compound 60, the third powder material 70, and the pulverized material 20 decreases, which may make the mixture difficult to knead. As a result, the pulverized material 20 becomes difficult to mix with the master batch compound 60.

[0040] In contrast, in the above-described method for producing a resin composition, the master batch compound 60, the third powder material 70, and the pulverized material 20 are kneaded to produce a kneaded material 80, and then the kneaded material 80 and the master batch compound 60 are kneaded to produce a soft polyvinyl chloride resin composition. In this way, by kneading the master batch compound 60 twice, the plasticizer 50 contained in the master batch compound 60 is easily kneaded with the pulverized material 20 during the first kneading, and the master batch compound 60 is easily kneaded with the kneaded material 80 during the second kneading. In addition, during the first kneading, the calcium carbonate 71 contained in the third powder material 70 promotes the kneading of the pulverized material 20 and the master batch compound 60. Therefore, the hard polyvinyl chloride contained in the pulverized material 20 is uniformly softened by the plasticizer 50.

[0041] When the kneaded material 80 is produced, the master batch compound 60 and the pulverized material 20 are easily mixed because they are both polyvinyl chloride. Also, when the soft polyvinyl chloride resin composition is produced, the kneaded material 80 and the master batch compound 60 are easily mixed because they are both polyvinyl chloride. Accordingly, the plasticizer 50 contained in the master batch compound 60 is also easily mixed into each of the pulverized material 20 and the kneaded material 80. Therefore, the time required for kneading each of the kneaded material 80 and the resin composition can be shortened. Also, the plasticizer 50 contained in the master batch compound 60 becomes more compatible with each of the pulverized material 20 and the kneaded material 80, and the amount of the plasticizer 50 added to the resin composition can be increased.

[0042] Therefore, the resin shaped material 10 mainly composed of rigid polyvinyl chloride can be recycled to easily produce a resin composition of flexible polyvinyl chloride. In addition, the concentration of the plasticizer 50 in the resin composition can be increased, and the range of hardness of the resin composition that can be produced can be expanded. A soft resin composition can also be produced. Even if the amount of calcium carbonate added is increased, the concentration of the plasticizer 50 can be increased to lower the hardness of the resin composition. This makes it possible to suppress the deterioration of the physical properties of the resin composition. Therefore, the amount of calcium carbonate added can be increased, and this makes it possible to reduce the cost of the material of the resin composition. By producing a resin composition using the pulverized material 20 that can be formed relatively easily, the resin shaped material 10 can also be efficiently recycled.

[0043] Pellets 81 are formed from the kneaded material 80, and the pellets 81 of the kneaded material 80 are kneaded with the master batch compound 60. Therefore, during kneading, the pellets 81 of the kneaded material 80 are dispersed in the master batch compound 60, so that the kneaded material 80 and the master batch compound 60 can be smoothly kneaded.

[0044] When the plasticizer 50 is less than 150 parts by weight relative to 100 parts by weight of the first powder material 30, the amount of the plasticizer 50 contained in the master batch compound 60 is reduced, which may affect the effect of the master batch compound 60 in softening the pulverized material 20 (rigid polyvinyl chloride) and the kneaded material 80. When the plasticizer 50 is more than 250 parts by weight relative to 100 parts by weight of the first powder material 30, the first powder material 30 may not be able to absorb the plasticizer 50, and the plasticizer 50 may remain in liquid form. On the other hand, when the plasticizer 50 is within a range of 150 parts by weight to 250 parts by weight relative to 100 parts by weight of the first powder material 30, the plasticizer 50 is absorbed by the first powder material 30 without waste, and the effect of the master batch compound 60 in softening the pulverized material 20 and the kneaded material 80 can be secured. It is more preferable that the plasticizer 50 is 170 parts by weight or more and 230 parts by weight or less for 100 parts by weight of the first powder material 30. This allows the plasticizer 50 to be smoothly absorbed into the first powder material 30, and the master batch compound 60 can reliably soften the pulverized material 20 and the kneaded material 80.

[0045] When the amount of the master batch compound 60 is less than 30 parts by weight relative to 100 parts by weight of the ground material 20, the amount of the plasticizer 50 of the master batch compound 60 mixed with the ground material 20 is reduced, which may affect the effect of softening the ground material 20 (rigid polyvinyl chloride) by the master batch compound 60. When the amount of the master batch compound 60 is more than 60 parts by weight relative to 100 parts by weight of the ground material 20, the amount of the master batch compound 60 increases, making it difficult to mix the master batch compound 60 with the ground material 20, which may cause uneven softening of the ground material 20. On the other hand, when the amount of the master batch compound 60 is within the range of 30 parts by weight to 60 parts by weight relative to 100 parts by weight of the ground material 20, the master batch compound 60 can be easily mixed with the ground material 20, and the ground material 20 can be stably softened by the plasticizer 50 contained in the master batch compound 60. It is more preferable that the masterbatch compound 60 is 35 parts by weight or more and 55 parts by weight or less per 100 parts by weight of the ground material 20. This allows the masterbatch compound 60 to be smoothly mixed with the ground material 20, and the plasticizer 50 contained in the masterbatch compound 60 can reliably soften the ground material 20.

[0046] The hardness of the soft polyvinyl chloride resin composition is adjusted to a target hardness by adjusting the amount of the masterbatch compound 60 added to 100 parts by weight of the kneaded material 80 within a range of more than 0 parts by weight and not more than 100 parts by weight. On the other hand, when the amount of the masterbatch compound 60 is more than 100 parts by weight to 100 parts by weight of the kneaded material 80, the amount of the masterbatch compound 60 increases, making it difficult to knead the masterbatch compound 60 with the kneaded material 80, and there is a risk of uneven kneading of the masterbatch compound 60 and the kneaded material 80. In addition, the proportion of the pulverized material 20 used in the production of the soft polyvinyl chloride resin composition decreases, and there is a risk of affecting the cost of the material of the resin composition. When the amount of the master batch compound 60 is within a range of more than 0 parts by weight and not more than 100 parts by weight per 100 parts by weight of the kneaded material 80, the hardness of the soft polyvinyl chloride resin composition can be adjusted while the master batch compound 60 can be easily kneaded with the kneaded material 80, and the amount of recycled resin shaped material 10 can be ensured. It is more preferable that the amount of the master batch compound 60 is more than 0 parts by weight and not more than 80 parts by weight per 100 parts by weight of the kneaded material 80. This allows the master batch compound 60 to be smoothly kneaded with the kneaded material 80, and the amount of recycled resin shaped material 10 can be reliably ensured.

[0047] When the amount of the third powder material 70 is less than 5 parts by weight relative to 100 parts by weight of the pulverized material 20, the effect of promoting the kneading of the pulverized material 20 and the master batch compound 60 due to the solid calcium carbonate 71 contained in the third powder material 70 may be affected. When the amount of the third powder material 70 is more than 50 parts by weight relative to 100 parts by weight of the pulverized material 20, the concentration of calcium carbonate in the soft polyvinyl chloride resin composition increases, which may affect the physical properties (e.g., elongation characteristics) of the resin composition. On the other hand, when the amount of the third powder material 70 is within a range of 5 parts by weight to 50 parts by weight relative to 100 parts by weight of the pulverized material 20, the physical properties of the resin composition can be secured while promoting the kneading of the pulverized material 20 and the master batch compound 60. It is more preferable that the amount of the third powder material 70 is 15 parts by weight to 40 parts by weight relative to 100 parts by weight of the pulverized material 20. This ensures that the mixing of the pulverized material 20 and the master batch compound 60 is promoted while the physical properties of the resin composition are maintained.

[0048] When the maximum dimension R of the pulverized material 20 is larger than 15 mm, the pulverized material 20 becomes large, which may make it difficult to knead the pulverized material 20 with the master batch compound 60 and the third powder material 70. On the other hand, when the maximum dimension R of the pulverized material 20 is 15 mm or less, the pulverized material 20 can be dispersed during kneading, and the pulverized material 20 can be easily kneaded with the master batch compound 60 and the third powder material 70. It is more preferable that the maximum dimension R of the pulverized material 20 is 8 mm or less. This allows the pulverized material 20 to be smoothly kneaded with the master batch compound 60 and the third powder material 70.

[0049] The softening temperature of the resin is the temperature (softening point) at which the resin softens and begins to deform. The softening temperature of the pulverized material 20 mainly composed of hard polyvinyl chloride is different from that of the kneaded material 80 (pellets 81) mainly composed of soft polyvinyl chloride, and the softening temperature of the hard polyvinyl chloride and the pulverized material 20 is higher than that of the soft polyvinyl chloride and the kneaded material 80.

[0050] When producing the kneaded material 80, the master batch compound 60, the third powder material 70, and the pulverized material 20 are heated to a temperature in the range of 160°C to 190°C. This softens the pulverized material 20, adjusts the viscosity of the pulverized material 20 to a viscosity suitable for kneading, and makes it easier to knead the pulverized material 20 with the master batch compound 60 and the third powder material 70. It is more preferable that the temperature at which the master batch compound 60, the third powder material 70, and the pulverized material 20 are heated is a temperature in the range of 170°C to 180°C. This prevents the viscosity of the pulverized material 20 from becoming too high or too low, and allows the pulverized material 20 to be smoothly kneaded with the master batch compound 60 and the third powder material 70.

[0051] When producing a resin composition of soft polyvinyl chloride, the kneaded material 80 and the master batch compound 60 are heated to a temperature in the range of 120°C to 165°C. This softens the kneaded material 80, adjusts the viscosity of the kneaded material 80 to a viscosity suitable for kneading, and makes it easier to knead the kneaded material 80 with the master batch compound 60. The temperature at which the kneaded material 80 and the master batch compound 60 are heated is more preferably in the range of 130°C to 155°C. This prevents the viscosity of the kneaded material 80 from becoming too high or too low, and allows the kneaded material 80 to be smoothly kneaded with the master batch compound 60.

[0052] When the particle size of the first powder material 30 is larger than 500 μm, there is a risk that the absorption of the plasticizer 50 into the first powder material 30 may be affected. In contrast, when the particle size of the first powder material 30 is 500 μm or less, the plasticizer 50 is easily absorbed into the first powder material 30, and the plasticizer 50 can be efficiently absorbed into the first powder material 30. As a result, the master batch compound 60 can be easily produced.

[0053] As the first powder material 30, either or both of unused hard polyvinyl chloride powder and recycled hard polyvinyl chloride powder may be used. Also, the kneaded mixture 80 may be kneaded with the master batch compound 60 without forming pellets 81 from the kneaded mixture 80. When a resin composition of soft polyvinyl chloride is colored, a pigment is added and kneaded at any stage between the production of the kneaded mixture 80 and the production of the resin composition (for example, the stage of producing the resin composition). When the resin shaped material 10, which is the raw material of the resin composition, is a scrap of the resin shaped material 10 (here, the resin shaped material 10 of the resin window), the scrap of the resin shaped material 10 can be recycled to reduce the cost of the resin composition.

[0054] FIG. 4 is a diagram showing another example of the resin shaped material 10 of the present embodiment, showing a cross section perpendicular to the longitudinal direction of the resin shaped material 10. As shown in FIG. As shown in the figure, the resin shaped material 10 has a main body 11 made mainly of hard polyvinyl chloride and an attached part 12 made mainly of soft polyvinyl chloride. The attached part 12 is a soft part attached to the main body 11 which is a hard part, and is formed smaller than the main body 11 so as to protrude from the main body 11. When crushing the resin shaped material 10 (S102 in FIG. 1), the attached part 12 is not removed from the main body 11, but the resin shaped material 10 with the attached part 12 attached to the main body 11 is crushed to form crushed material 20 of the resin shaped material 10.

[0055] The crushed material 20 formed includes crushed material 20 having only the main body portion 11, crushed material 20 having only the attachment portion 12, and crushed material 20 including both the main body portion 11 and the attachment portion 12. The master batch compound 60 and the third powder material 70 are kneaded to obtain a kneaded material 80. In this manner, the resin shaped material 10 can be easily recycled without separating the main body 11 made of hard polyvinyl chloride from the accessory portion 12 made of soft polyvinyl chloride.

[0056] Although the above describes an example in which the resin shaped material 10 is an end piece of the resin shaped material 10 of a resin window, the resin shaped material 10 is not limited to the resin shaped material 10 of a resin window, and may be another resin shaped material 10. The other resin shaped material 10 is, for example, a rigid polyvinyl chloride shaped material (PVC shaped material) used for purposes other than resin windows, a rigid polyvinyl chloride shaped material (PVC shaped material with soft material) with an attached part of soft polyvinyl chloride used for purposes other than resin windows, a heat-resistant rigid polyvinyl chloride shaped material (heat-resistant PVC shaped material), a rigid polyvinyl chloride shaped material laminated with acrylic resin (acrylic laminated PVC shaped material), or a rigid polyvinyl chloride shaped material (laminated shaped material) with a resin laminate sheet (for example, an olefin resin sheet) attached to the surface.

[0057] Next, examples of the method for producing a flexible polyvinyl chloride resin composition will be described, but the present invention is not limited to the following examples. In the examples, a flexible polyvinyl chloride resin composition was produced according to the flow chart shown in FIG.

[0058] [Table 1]

[0059] Table 1 shows the parts by weight of each material at each stage of the example. When the master batch compound 60 was produced, 200 parts by weight of the plasticizer 50 and 2.5 parts by weight of the second powder material 40 were added to 100 parts by weight of the first powder material 30. The plasticizer 50 was diisononyl phthalate (DINP), and the second powder material 40 was a barium-zinc-based (Ba-Zn-based) stabilizer. When the kneaded material 80 was produced, 45 parts by weight of the master batch compound 60 and 25 parts by weight of the third powder material 70 were added to 100 parts by weight of the pulverized material 20. When the soft polyvinyl chloride resin composition was produced, 24 parts by weight of the master batch compound 60 were added to 100 parts by weight of the kneaded material 80. In the embodiment, the resin shape 10 was recycled to produce a soft polyvinyl chloride resin composition.

[0060] As described above, the present embodiment discloses a method for producing a resin composition described in the following (1) to (6).

[0061] (1) A method for producing a resin composition, which uses a resin extrusion material mainly composed of rigid polyvinyl chloride as a raw material to produce a flexible polyvinyl chloride resin composition, comprising the steps of: A crushing step of crushing the resin shaped material to form a crushed material; A kneading step of kneading a master batch mixture containing rigid polyvinyl chloride, a stabilizer, and a plasticizer, a powder material containing calcium carbonate as a main component, and the pulverized material while heating them to obtain a kneaded mixture; a mixing step of kneading the kneaded material and the master batch compound while heating to produce the resin composition in which the kneaded material and the master batch compound are mixed; A method for producing a resin composition comprising the steps of: In the method for producing a resin composition described in (1), a resin extrusion material mainly composed of rigid polyvinyl chloride can be recycled to easily produce a flexible polyvinyl chloride resin composition.

[0062] (2) A method for producing a resin composition according to (1), comprising the steps of: A step of processing the kneaded material to form pellets of the kneaded material, In the mixing step, the pellets of the kneaded product and the master batch compound are kneaded while being heated. In the method for producing a resin composition described in (2), pellets of the kneaded product are dispersed in the master batch compound, so that the kneaded product and the master batch compound can be smoothly kneaded together.

[0063] (3) A method for producing a resin composition according to (1) or (2), comprising the steps of: A method for producing a resin composition, comprising the step of adding 150 parts by weight or more and 250 parts by weight or less of the plasticizer to 100 parts by weight of a powder material mainly composed of rigid polyvinyl chloride, to produce the master batch composition. In the method for producing a resin composition described in (3), the powder material mainly composed of rigid polyvinyl chloride can absorb the plasticizer without waste, thereby ensuring the effect of softening the ground material and kneaded material by the masterbatch compound.

[0064] (4) A method for producing a resin composition according to any one of (1) to (3), In the kneading step, 30 parts by weight or more and 60 parts by weight or less of the master batch compound are added to 100 parts by weight of the pulverized material, The method for producing a resin composition, wherein the mixing step adds more than 0 part by weight and 100 parts by weight or less of the master batch compound to 100 parts by weight of the kneaded material. In the method for producing a resin composition described in (4), the masterbatch compound can be easily mixed with the ground material, and the ground material can be stably softened by the plasticizer contained in the masterbatch compound. In addition, the masterbatch compound can be easily mixed with the kneaded material while adjusting the hardness of the soft polyvinyl chloride resin composition, and the amount of recycled resin shapes can be secured.

[0065] (5) A method for producing a resin composition according to any one of (1) to (4), In the kneading step, 5 parts by weight or more and 50 parts by weight or less of powder material containing calcium carbonate as a main component is added to 100 parts by weight of the pulverized material. In the method for producing a resin composition described in (5), the kneading of the ground material and the master batch compound can be promoted while ensuring the physical properties of the soft polyvinyl chloride resin composition.

[0066] (6) A method for producing a resin composition according to any one of (1) to (5), A method for producing a resin composition, wherein in the kneading step, the maximum dimension of the pulverized material is 15 mm or less. In the method for producing a resin composition described in (6), the ground material can be dispersed and easily kneaded with the master batch compound and the powder material mainly composed of calcium carbonate. [Explanation of symbols]

[0067] 10···Resin profile, 11···Main body, 12···Accessory part, 20···Grounded material, 30···First powder material, 40···Second powder material, 50···Plasticizer, 60···Masterbatch compound, 70···Third powder material, 71···Calcium carbonate, 80···Kneaded material, 81···Pellets, R···Maximum dimension.

Claims

1. A method for producing a resin composition, comprising the steps of: producing a flexible polyvinyl chloride resin composition using a resin shape material mainly composed of rigid polyvinyl chloride as a raw material, the method comprising the steps of: A crushing step of crushing the resin shaped material to form a crushed material; A kneading step of kneading a master batch mixture containing rigid polyvinyl chloride, a stabilizer, and a plasticizer, a powder material containing calcium carbonate as a main component, and the pulverized material while heating them to obtain a kneaded mixture; a mixing step of kneading the kneaded material and the master batch compound while heating to produce the resin composition in which the kneaded material and the master batch compound are mixed; A method for producing a resin composition comprising the steps of:

2. The method for producing a resin composition according to claim 1, A step of processing the kneaded material to form pellets of the kneaded material, In the mixing step, the pellets of the kneaded product and the master batch compound are kneaded while being heated.

3. The method for producing the resin composition according to claim 1 or 2, A method for producing a resin composition, comprising the step of adding 150 parts by weight or more and 250 parts by weight or less of the plasticizer to 100 parts by weight of a powder material mainly composed of rigid polyvinyl chloride to produce the master batch composition.

4. The method for producing the resin composition according to claim 1 or 2, In the kneading step, 30 parts by weight or more and 60 parts by weight or less of the master batch compound are added to 100 parts by weight of the pulverized material, In the mixing step, more than 0 part by weight and 100 parts by weight or less of the master batch compound is added to 100 parts by weight of the kneaded product.

5. The method for producing the resin composition according to claim 1 or 2, In the kneading step, 5 parts by weight or more and 50 parts by weight or less of powder material containing calcium carbonate as a main component is added to 100 parts by weight of the pulverized material.

6. The method for producing the resin composition according to claim 1 or 2, A method for producing a resin composition, wherein in the kneading step, the maximum dimension of the pulverized material is 15 mm or less.

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