JPH06134835A - Vinyl chloride base resin composition - Google Patents

Abstract

PURPOSE:To provide a vinyl chloride base resin composition which can be sufficiently coped with a shape change of an extrusion port when a vinyl chloride resin molded form is extrusion-molded by a mold in which the port is deformed by a main die and a subdie and improve the productivity in the case of molding the resin. CONSTITUTION:Vinyl chloride base resin composition is used to be extrusion molded in such a manner that a sectional shape is varied along an extruding direction by using a mold having a main die 12 and a subdie 22 movable along extrusion ports 13-17. The composition is formed by copolymerizing alkyl ester or alpha-olefin at a ratio of 1-8wt.% with vinyl chloride.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride resin composition, and more specifically, it uses a molding die having a main die and a sub die movable along the extrusion port and has a cross-sectional shape along the extrusion direction. The present invention relates to a vinyl chloride resin composition suitable for extrusion molding that changes with time.

[0002]

2. Description of the Related Art In recent years, in extrusion molding, it has been proposed to change the extrusion shape by the constitution of a main die and a sub die movable along the extrusion port (Japanese Patent Laid-Open No. 59-114040, Japanese Patent Application Laid-Open No. 59-114040). Kaihei 4-159
154). Conventionally, rubber has mainly been used as a material for this type of extrusion molding (molding material) for changing the shape of the extrusion port, but recently thermoplastic resins, particularly vinyl chloride resins have been investigated. That is, the semi-hard and soft vinyl chloride resins, which have increased flexibility by adding a plasticizer to the vinyl chloride resin, have better moldability than rubber, and this molded product has a good appearance design and weather resistance. Therefore, it is used as a molding material for vehicle parts.
As in the case of extrusion molding of rubber (rubber before cross-linking), it is desirable that the extrusion resin of vinyl chloride resin also sufficiently responds to the change of the extrusion port in extrusion molding of vinyl chloride resin.

[0003]

However, unlike the case of extruding rubber (rubber before cross-linking), the vinyl chloride resin added with a plasticizer has a poor shape-retaining property because the resin melts and softens during extrusion. Therefore, it becomes difficult to extrude while maintaining the shape against the operation of the movable sub-die. In particular, a phenomenon occurs in which the boundary between the fixed shape part and the operating shape part of the die is damaged as the sub die is operated. Therefore, the amount of change of the member itself is reduced or the extrusion speed is reduced to relatively slow the operation of the sub-die, which causes a problem in freedom of member design or productivity.

Therefore, an object of the present invention is to sufficiently cope with the change in shape of the extrusion port when the extrusion molding is carried out by a molding die in which the extrusion port is deformed by the main die and the sub die to obtain a vinyl chloride resin molded product. It is to provide a vinyl chloride resin composition that can be obtained and can improve the productivity of resin molding.

[0005]

In view of the above-mentioned problems, the present inventor has conducted a test study on the material properties of vinyl chloride-based resin, and as a result, as a material suitable for shape change extrusion, among the material properties immediately after discharge from a die, It has been found that by improving the elongation at the time of melting and softening, extrusion can be performed without impairing the shape even when the sub-die operates, and the present invention has been accomplished.

[0006] That is, the means of the present invention for achieving the above-mentioned object uses a forming die having a main die and a sub die movable along the extrusion port, and the cross-sectional shape changes along the extrusion direction. A vinyl chloride resin composition used for extrusion molding, characterized in that an alkyl ester or α-olefin is copolymerized with vinyl chloride at a ratio of 1% by weight or more and 8% by weight or less.

The vinyl chloride resin according to the present invention is equivalent to vinyl chloride for general-purpose extrusion molding having a polymerization degree of 900 to 2000, but in order to increase the elongation at the time of melt softening, vinyl chloride and other monomers are used. Modification by copolymerization. The vinyl chloride resin has been modified by copolymerization for a long time, but the purpose was to improve the workability by improving the fluidity rather than the physical properties of the molded product. In the present invention, the internal plasticizing effect of the copolymer increases the elongation at the time of melting and softening, and improves the shape retention with respect to the operation of the sub-die, thereby improving the overall extrusion rate.

As the combination of copolymerization, an alkyl ester represented by acrylic acid or methacrylic acid and an α-olefin represented by ethylene or propylene can be mentioned. The alkyl ester or α-olefin must be blended with vinyl chloride in a proportion of 1% by weight or more and 8% by weight or less and copolymerized. The alkyl ester and α-olefin may be used alone or in combination of two or more. If the amount is less than 1% by weight, there is no modification effect, and if it exceeds 8% by weight, the heat resistance decreases and the change in melt elongation due to temperature change (in proportion to the increase in the copolymerization rate) is large. This is not preferable because it is difficult to control the resin temperature during extrusion molding. Even within the favorable range of 1 to 8% by weight, the heat resistance becomes large when the amount of the alkyl ester or α-olefin is small, and the heat resistance becomes small and the workability becomes good when the amount of the alkyl ester or α-olefin is large. In the range of 1 to 8% by weight, the extrusion speed can be set to 2.0 to 8.0 m / min, which is sufficiently practical for the operation of the sub-die. Incidentally, the copolymerization of vinyl chloride may be carried out in the same manner with a vinyl ester such as vinyl acetate, and it may be possible to improve the elongation at the time of melt softening by copolymerizing alkyl vinyl ether, acrylonitrile or the like. .

Generally, in order to obtain a plasticizing effect, a plasticizer (DOP, DINP, etc.) is added. However, addition of a simple plasticizer cannot significantly increase the elongation at the time of melt softening. It only deteriorates the physical properties extremely. The copolymerization of vinyl chloride with an alkyl ester or α-olefin is a mechanochemical reaction, a combination of polycondensation and radical polymerization, a method by ozonide or polyaddition,
This can be done by a conventionally known method.

[0010]

EXAMPLES First, a vinyl chloride homopolymer serving as a control (resin) and a copolymer obtained by copolymerizing ethylene with vinyl chloride at a predetermined copolymerization ratio as material resins A to F are prepared.
The elongation during melting and softening of these was examined. The degree of polymerization and ethylene copolymerization rate of the control and material resins A to F are as shown in Table 1.

[0011]

The elongation of the control and each of the material resins A to F during melt softening was measured by a melt strength device. In this example, the melt strength apparatus of Capillograph manufactured by Toyo Seiki Co., Ltd. was used. That is, this device is shown in FIG.
As shown in FIG. 3, the material resin in the melted and softened state in the resin supply unit 31, for example, A is pressed by the pressure piston 33 and extruded from the small hole 35 of the capillary 34 as the resin thread 32A. Through the take-up roll 38. In addition, 39 is a tension spring. The take-up roll 38 is connected to a rotation speed adjusting means 40 whose rotation speed is sequentially increased, and the rotation speed immediately before the resin thread 32A is cut is recorded as a limit speed.

The measurement results of the control and each of the material resins A to F are shown in Table 2. It was confirmed that each of the resin materials A to F had a value larger than that of the control.

[0014]

Next, the respective material resins A to F are extruded from the extrusion ports 15, 16 (13, 14) of the main die 12 shown in FIG.
3 is actually molded by the extrusion molding die 11 in which the sub die 22 moves, and the moldability thereof is improved by the material resin A for each movement of the sub die 22.
The moldability of ~ F was investigated.

As shown in FIG. 3, the vehicle mall 1 is
A resin-made lip 5 is provided on the narrow outer surface 3 of the molded core metal 2.
Is extruded integrally with the cored bar 2 in the longitudinal direction, and has a wide outer surface 4 on which a water guide 6, a coating layer 7 and a protector 8 are formed.
Is formed by adhesion in the longitudinal direction. In particular, in the vehicle molding 1 of this example, the mounting position of the protector 8 is slanted from the lower part to the upper part of the wide outer surface as shown in FIG. It is provided via the shaped portion 8A. The extrusion mold 11 used in this example is a molding for a vehicle in which a core resin 2 formed by pre-bending is extruded, and a molten resin is extruded along the core metal 2 to adhere the molding resin to the core metal 2. To get 1.

As shown in FIG. 1, the extrusion mold 1 of this example is shown.
The main component 1 is a main die 12 and a protector molding sub die 22. Predetermined extrusion ports 13, 14, 15, 16, 17 are provided by both dies. A recess 18 communicating with one side of the extrusion port 16 is provided at a predetermined side portion of the main die 12 that serves as the extrusion port 16, and the sub-die 22 is accommodated in the recess 18 in a state instructed by the guide member 23 to move up and down. A predetermined distance H can be moved in the direction. The sub die 22 has an extrusion opening 17 for forming the protector 8 on the extrusion opening 16 side of the main die 12, and the sub die 22 is connected to the elevating means 25 below the extrusion molding die 11 via a rod 24. At the required extrusion position, the predetermined interval H can be sequentially increased from the position of the sub die 22 of FIG. 1 to the position of the sub die 22 of FIG. Extrusion ports 13, 14, 15, 1
Reference numeral 6 has a predetermined shape for allowing the core metal 2 to be inserted therethrough, and for forming the lip 5, the water guide 6 and the protector 8 on each predetermined part of the core metal 2 with a molten resin.

Then, each of the prepared resin materials A to F was extruded into the extrusion mold 11 to form the molding 1 for a vehicle. The extrusion molding is based on the control resin, and each material resin A to F is extruded at a constant extrusion rate (practical speed for mass production 4 m / min) while the sub die 2
2 was moved, and the operating speed at which the sub die 22 was moved was gradually increased, and the maximum operating speed of the sub die 22 in which the extrusion direction could be changed while maintaining the shape was examined. In this case, a material resin capable of operating the sub die 22 at a speed of 5 mm / sec or more is regarded as a practical pass, and 10 mm / s
An ideal material resin is one that can operate at a speed of ec or higher. The molding results of each of the material resins A to F are shown in Table 3.
In Table 3, x, Δ, and ◯ are indicated by x: movable 5 mm / sec, Δ: movable 5 to 10 mm / sec, ◯: movable 10 mm / sec or more.

[0019]

From the results shown in Table 3, the control and the material resin A failed because they could not achieve the practical operating speed of the sub die 22. The resin materials B to F are acceptable, and especially the material resin E,
F was ideal. That is, the material resins B to F can sufficiently perform molding in accordance with the practical operating speed (5 mm / sec) of the sub die 22.

In this example, ethylene was selected as the copolymerization component of vinyl chloride, but according to another test by the present inventor, it was recognized that similar results were obtained in the case of methyl methacrylate. It was In addition, although the extrusion molding of the present embodiment is the case where the molding resin is molded and adhered to the core metal, the extrusion molding can also be performed in the extrusion molding without using the core metal.

[0022]

EFFECTS OF THE INVENTION The present invention is a vinyl chloride resin composition obtained by copolymerizing an alkyl ester or an α-olefin at a ratio of 1 to 8% by weight with respect to vinyl chloride, and therefore melt-softens without impairing heat resistance. The elongation over time can be modified. Therefore, when used for extrusion molding in which the cross-sectional shape changes along the extrusion direction using a molding die having a main die and a sub die movable along the extrusion opening, it corresponds to the shape change of the extrusion opening. A good molded product can be obtained. Further, since the vinyl chloride resin composition of the present invention has a modified melt property during extrusion,
Even when operating the sub-die several steps earlier than the normal extrusion speed and conventional general-purpose vinyl chloride resin,
This is convenient because it can be sufficiently dealt with and the productivity of extrusion molding can be improved.

[Brief description of drawings]

FIG. 1 is a front view of an extrusion molding die.

FIG. 2 is a view showing a usage mode of an extrusion molding die.

FIG. 3 is a perspective view of a molded molding.

FIG. 4 is an illustration of a melt strength device for measuring Max's pull rate.

[Explanation of Codes] 11 ... Extrusion Mold 12 ... Main Die 13, 14, 15, 16, 17 ... Extrusion Port 22 ... Sub Die

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 17, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be amended] Detailed explanation of the invention

[Correction method] Change

[Correction content]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride resin composition, and more specifically, it uses a molding die having a main die and a sub die movable along the extrusion port and has a cross-sectional shape along the extrusion direction. The present invention relates to a vinyl chloride resin composition suitable for extrusion molding that changes with time.

[0002]

2. Description of the Related Art In recent years, in extrusion molding, it has been proposed to change the extrusion shape by the constitution of a main die and a sub die movable along the extrusion port (Japanese Patent Laid-Open No. 59-114040, Japanese Patent Application Laid-Open No. 59-114040). Kaihei 4-159
154). Conventionally, rubber has been the main material for this type of extrusion molding (molding material) that changes the shape of the extrusion port, but recently thermoplastic resins, particularly vinyl chloride resins, have been investigated. That is, the semi-hard and soft vinyl chloride resins, which have increased flexibility by adding a plasticizer to the vinyl chloride resin, have better moldability than those of rubber, and this molded product has a good appearance design and weather resistance. Therefore, it is used as a molding material for vehicle parts.
As in the case of extrusion molding of rubber (rubber before cross-linking), it is desired that the extrusion resin of vinyl chloride resin also sufficiently responds to the change of the extrusion port.

[0003]

However, unlike the case of extruding rubber (rubber before cross-linking), the vinyl chloride resin added with a plasticizer has a poor shape-retaining property because the resin melts and softens during extrusion. Therefore, it becomes difficult to extrude while maintaining the shape against the operation of the movable sub-die. In particular, a phenomenon occurs in which the boundary between the fixed shape part and the operating shape part of the die is damaged as the sub die is operated. Therefore, the amount of change of the member itself is reduced or the extrusion speed is reduced to relatively slow the operation of the sub-die, which causes a problem in freedom of member design or productivity.

Therefore, an object of the present invention is to sufficiently cope with the change in shape of the extrusion port when the extrusion molding is carried out by a molding die in which the extrusion port is deformed by the main die and the sub die to obtain a vinyl chloride resin molded product. It is to provide a vinyl chloride resin composition that can be obtained and can improve the productivity of resin molding.

[0005]

In view of the above-mentioned problems, the present inventor has conducted a test study on the material properties of vinyl chloride-based resin, and as a result, as a material suitable for shape change extrusion, among the material properties immediately after discharge from a die, It has been found that by improving the elongation at the time of melting and softening, extrusion can be performed without impairing the shape even when the sub-die operates, and the present invention has been accomplished.

[0006] That is, the means of the present invention for achieving the above-mentioned object uses a forming die having a main die and a sub die movable along the extrusion port, and the cross-sectional shape changes along the extrusion direction. A vinyl chloride resin composition used for extrusion molding, characterized in that an alkyl ester or α-olefin is copolymerized with vinyl chloride at a ratio of 1% by weight or more and 8% by weight or less.

The vinyl chloride resin according to the present invention is equivalent to vinyl chloride for general-purpose extrusion molding having a polymerization degree of 900 to 2000, but in order to increase the elongation at the time of melt softening, vinyl chloride and other monomers are used. Modification by copolymerization. The vinyl chloride resin has been modified by copolymerization for a long time, but the purpose was to improve the workability by improving the fluidity rather than the physical properties of the molded product. In the present invention, the internal plasticizing effect of the copolymer increases the elongation at the time of melting and softening, and improves the shape retention with respect to the operation of the sub-die, thereby improving the overall extrusion rate.

As the combination of copolymerization, an alkyl ester represented by acrylic acid or methacrylic acid and an α-olefin represented by ethylene or propylene can be mentioned. The alkyl ester or α-olefin must be blended with vinyl chloride in a proportion of 1% by weight or more and 8% by weight or less and copolymerized. The alkyl ester and α-olefin may be used alone or in combination of two or more. If the amount is less than 1% by weight, there is no modification effect, and if it exceeds 8% by weight, the heat resistance decreases and the change in melt elongation due to temperature change (in proportion to the increase in the copolymerization rate) is large. This is not preferable because it is difficult to control the resin temperature during extrusion molding. Even within the favorable range of 1 to 8% by weight, the heat resistance becomes large when the amount of the alkyl ester or α-olefin is small, and the heat resistance becomes small and the workability becomes good when the amount of the alkyl ester or α-olefin is large. In the range of 1 to 8% by weight, the extrusion speed can be set to 2.0 to 8.0 m / min, which is sufficiently practical for the operation of the sub-die. Incidentally, the copolymerization of vinyl chloride may be carried out in the same manner with a vinyl ester such as vinyl acetate, and it may be possible to improve the elongation at the time of melt softening by copolymerizing alkyl vinyl ether, acrylonitrile or the like. .

Generally, in order to obtain a plasticizing effect, a plasticizer (DOP, DINP, etc.) is added. However, addition of a simple plasticizer cannot significantly increase the elongation at the time of melt softening. It only deteriorates the physical properties extremely. The copolymerization of vinyl chloride with an alkyl ester or α-olefin is a mechanochemical reaction, a combination of polycondensation and radical polymerization, a method by ozonide or polyaddition,
This can be done by a conventionally known method.

[0010]

EXAMPLES First, a vinyl chloride homopolymer serving as a control (resin) and a copolymer obtained by copolymerizing ethylene with vinyl chloride at a predetermined copolymerization ratio as material resins A to F are prepared.
The elongation during melting and softening of these was examined. The degree of polymerization and ethylene copolymerization rate of the control and material resins A to F are as shown in Table 1.

[0011]

The elongation of the control and each of the material resins A to F during melt softening was measured by a melt strength device. In this example, the melt strength apparatus of Capillograph manufactured by Toyo Seiki Co., Ltd. was used. That is, this device is shown in FIG.
As shown in FIG. 3, the material resin in the molten and softened state in the resin supply part 31, for example, A, is pressed by the pressure piston 33 and extruded as the resin thread 32A from the small hole 35 of the capillary 34, and the resin thread 32A is pulled by the pulleys 36, 37. Through the take-up roll 38. In addition, 39 is a tension spring. The take-up roll 38 is connected to a rotation speed adjusting means 40 whose rotation speed is sequentially increased, and the rotation speed immediately before the resin thread 32A is cut is recorded as a limit speed.

The measurement results of the control and each of the material resins A to F are shown in Table 2. It was confirmed that each of the resin materials A to F had a value larger than that of the control.

[0014]

Next, the respective material resins A to F are extruded from the extrusion ports 15, 16 (13, 14) of the main die 12 shown in FIG.
3 is actually molded by the extrusion molding die 11 in which the sub die 22 moves, and the moldability thereof is improved by the material resin A for each movement of the sub die 22.
The moldability of ~ F was investigated.

As shown in FIG. 3, the vehicle mall 1 is
A resin-made lip 5 is provided on the narrow outer surface 3 of the molded core metal 2.
Is extruded integrally with the cored bar 2 in the longitudinal direction, and has a wide outer surface 4 on which a water guide 6, a coating layer 7 and a protector 8 are formed.
Is formed by adhesion in the longitudinal direction. In particular, in the vehicle molding 1 of this example, the mounting position of the protector 8 is slanted from the lower part to the upper part of the wide outer surface as shown in FIG. It is provided via the shaped portion 8A. The extrusion mold 11 used in this example is a molding for a vehicle in which a core resin 2 formed by pre-bending is extruded, and a molten resin is extruded along the core metal 2 to adhere the molding resin to the core metal 2. To get 1.

As shown in FIG. 1, the extrusion mold 1 of this example is shown.
The main component 1 is a main die 12 and a protector molding sub die 22. Predetermined extrusion ports 13, 14, 15, 16, 17 are provided by both dies. A recess 18 communicating with one side of the extrusion port 16 is provided at a predetermined side portion of the main die 12 that serves as the extrusion port 16, and the sub-die 22 is accommodated in the recess 18 in a state instructed by the guide member 23 to move up and down. A predetermined distance H can be moved in the direction. The sub die 22 has an extrusion opening 17 for forming the protector 8 on the extrusion opening 16 side of the main die 12, and the sub die 22 is connected to the elevating means 25 below the extrusion molding die 11 via a rod 24. At the required extrusion position, the predetermined interval H can be sequentially increased from the position of the sub die 22 of FIG. 1 to the position of the sub die 22 of FIG. Extrusion ports 13, 14, 15, 1
Reference numeral 6 has a predetermined shape for allowing the core metal 2 to be inserted therethrough, and for forming the lip 5, the water guide 6 and the protector 8 on each predetermined part of the core metal 2 with a molten resin.

Then, each of the prepared resin materials A to F was extruded into the extrusion mold 11 to form the molding 1 for a vehicle. The extrusion molding is based on the control resin, and each material resin A to F is extruded at a constant extrusion rate (practical speed for mass production 4 m / min) while the sub die 2
2 was moved, and the operating speed at which the sub die 22 was moved was gradually increased, and the maximum operating speed of the sub die 22 in which the extrusion direction could be changed while maintaining the shape was examined. In this case, a material resin capable of operating the sub die 22 at a speed of 5 mm / sec or more is regarded as a practical pass, and 10 mm / s
An ideal material resin is one that can operate at a speed of ec or higher. The molding results of each of the material resins A to F are shown in Table 3.
In Table 3, x, Δ, and ◯ are indicated by x: movable 5 mm / sec, Δ: movable 5 to 10 mm / sec, ◯: movable 10 mm / sec or more.

[0019]

From the results shown in Table 3, the control and the material resin A failed because they could not achieve the practical operating speed of the sub die 22. The resin materials B to F are acceptable, and especially the material resin E,
F was ideal. That is, the material resins B to F can sufficiently perform molding in accordance with the practical operating speed (5 mm / sec) of the sub die 22.

In this example, ethylene was selected as the copolymerization component of vinyl chloride, but according to another test by the present inventor, it was recognized that similar results were obtained in the case of methyl methacrylate. It was In addition, although the extrusion molding of the present embodiment is the case where the molding resin is molded and adhered to the core metal, the extrusion molding can also be performed in the extrusion molding without using the core metal.

[0022]

EFFECTS OF THE INVENTION The present invention is a vinyl chloride resin composition obtained by copolymerizing an alkyl ester or an α-olefin in a ratio of 1 to 8% by weight with respect to vinyl chloride, and therefore melt-softens without impairing heat resistance. The elongation over time can be modified. Therefore, when a molding die having a main die and a sub die movable along the extrusion port is used for extrusion molding in which the cross-sectional shape changes along the extrusion direction, it corresponds to the shape change of the extrusion port. A good molded product can be obtained. Further, since the vinyl chloride resin composition of the present invention has a modified melt property during extrusion,
Even when operating the sub-die several steps earlier than the normal extrusion speed and conventional general-purpose vinyl chloride resin,
This is convenient because it can be sufficiently dealt with and the productivity of extrusion molding can be improved.

Claims (1)

[Claims] 1. A vinyl chloride resin composition for use in extrusion molding, the cross-sectional shape of which changes along the extrusion direction using a molding die having a main die and a sub-die movable along the extrusion port. , For vinyl chloride 1
A vinyl chloride resin composition, which is obtained by copolymerizing an alkyl ester or an α-olefin in a ratio of from 8% by weight to 8% by weight.