JPH0221934B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) This invention relates to a foamed sheet of vinyl chloride, and is particularly suitable for being vacuum-formed, or having a synthetic resin injection-molded or blow-molded on the back side of the foamed sheet. It is related to.

(Prior Art) In various synthetic resin molded products such as automobile interior parts and indoor equipment products, in order to provide an excellent appearance and hide defects such as scratches and unevenness on the resin surface,
It is useful to decorate the surface with a separate material.
Furthermore, it is desirable to provide a foam layer on the surface of the resin molded product, not only to improve the appearance but also to make the product soft to the touch.

One method for forming this foam layer is to vacuum form a synthetic resin foam sheet and adhere it to the surface of a resin molded product, or to directly injection mold or blow mold a synthetic resin onto the back surface of the foam sheet. is possible.

(Problems to be Solved by the Invention) However, since the heating temperature or resin temperature during the vacuum forming, injection molding, or blow molding is considerably high,
There is a problem that the foam sheet may melt or be damaged by the heat. In particular, high tensile stress and heat are applied to stress concentrated areas such as the corners of the foam sheet and near gates in injection molding, so there is a possibility that the foam sheet will break or partially melt and peel off from the fabric. To increase.

Currently, it is considered to provide a heat insulating layer such as cloth on the back side of the foam sheet, but the foam sheet is still required to have high heat resistance. Furthermore, if a foam sheet and cloth are formed independently and then tried to be bonded using adhesive or heat fusion, not only will the number of manufacturing steps increase, but the bondability will not necessarily be high. There is also a risk that the foam sheet may peel off from the cloth due to the heat or external force.

Structure of the Invention (Means for Solving the Problems) Therefore, in order to solve the above problems, an isocyanate crosslinked type or triazine crosslinked type vinyl chloride paste resin foam is integrally laminated on the surface of the cloth, A decorative layer was provided on the surface of the vinyl chloride paste resin foam to form a foam sheet.

(Function) At the same time that an isocyanate crosslinked type or triazine crosslinked type vinyl chloride paste resin foam is formed on the surface of the cloth, the foam and the cloth are integrated. Therefore, the process of forming the foam and the process of attaching the foam to the cloth are integrated into one, which simplifies the manufacturing process as a whole and contributes to cost reduction.

Since the vinyl chloride paste resin penetrates into the surface of the cloth and captures the fibers or threads of the cloth, the foam is firmly attached to the cloth with a mechanical anchor effect, and its bondability is extremely high. Furthermore, isocyanate-crosslinked or triazine-crosslinked vinyl chloride paste resin foams have particularly excellent elongation and tensile strength properties at high temperatures.

Further, when the foam sheet is vacuum formed, or when a synthetic resin is injection molded, blow molded, or vacuum formed on the back side of the foam sheet, the cloth blocks the heat during the molding.

Therefore, the foam is hardly peeled off from the cloth or damaged by the heat and pressure during the molding process. In particular, the above-mentioned damage and peeling can be prevented even in stress concentrated parts such as corner parts of the foam sheet and in the vicinity of gates in injection molding.

Further, the decorative layer provided on the surface of the foam improves the appearance and protects the foam at the same time.

(Example) Next, an example in which the present invention is embodied in a foamed sheet for attachment to the surface of an automobile center pillar interior material will be described with reference to FIGS. 1 to 7.

1 in the drawing is a foamed sheet provided on the surface of the center pillar interior material, and is an isocyanate crosslinked type or triazine crosslinked type (hereinafter referred to as crosslinked type) chlorinated foam sheet integrally laminated on the cloth 2 and its surface. It is composed of a vinyl paste resin foam 3. The cloth 2 is a plain woven cloth made of polyester fiber yarn. The vinyl chloride paste resin foam 3 is formed of a crosslinked type vinyl chloride paste resin foam to which a blowing agent is added, and the details thereof will be described later.

Reference numeral 4 denotes a decorative layer provided on the surface of the foam 3, which is made of cross-linked vinyl chloride paste resin to which no foaming agent is added, and whose surface has a textured pattern.

5 is a base material of the center pillar interior material, and is formed by injection molding polypropylene resin (hereinafter referred to as PP resin) on the back surface of cloth 2. The boundary portion of the PP resin with respect to the cloth 2 is hardened after penetrating between the threads of the cloth 2 as shown in FIG. 2 due to the injection pressure during molding. Additionally, the heat generated during injection molding causes the PP resin to melt some of the threads and fuse with them. Therefore, the cloth 2 is firmly joined to the base material 5 by mechanical anchoring effect or fusion.

Now, the vinyl chloride paste resin foam 3
Explain the details.

Vinyl chloride paste resin refers to a mixture of a vinyl chloride copolymer, a plasticizer, a stabilizer, etc. that is in a sol paste state before being heat-cured.

What is cross-linked vinyl chloride paste resin?
This includes the above-mentioned isocyanate crosslinked type, triazine crosslinked type, or a mixture of these and non-crosslinked vinyl chloride paste resins.

Furthermore, the above-mentioned isocyanate crosslinked type vinyl chloride paste resin is one whose main components are a vinyl chloride copolymer having a hydroxyl group (for example, manufactured by Mitsubishi Monsanto, trade name Vinica P100) and an isocyanate as its crosslinking agent. . Moreover, the triazine crosslinked type vinyl chloride paste resin is one whose main components are a vinyl chloride copolymer and triazine, which is a crosslinking agent for the vinyl chloride copolymer.

Further, as the blowing agent added to the foam 3, an organic blowing agent such as azodicarbonamide can be used. Note that the vinyl chloride paste resin can also be foamed by mechanical foaming without using a foaming agent.

As described above, the cross-linked vinyl chloride paste resin to which a foaming agent has been added is applied to the cloth 2 in the form of a sol paste, and after penetrating into the fibers or threads on the surface of the cloth 2 as shown in FIG. Foamed and heated to harden. Therefore, the foam 3 is firmly bonded to the cloth 2 due to the mechanical anchoring effect.

Next, a method for manufacturing the foam sheet 1 of this example will be explained.

First, as shown in FIG. 3, a roll of release paper 6 with a grained negative image formed on its surface is set in the form of a roll and sequentially fed to the right. Next, a foaming agent-free vinyl chloride paste resin RA constituting the decorative layer 4 is supplied onto the release paper 6, applied with a squeegee while adjusting the thickness, and cured by heating with an infrared heater 7. proceed.

Subsequently, a foaming agent-added vinyl chloride paste resin RB constituting the foam 3 is supplied onto the vinyl chloride paste resin RA and applied with a squeegee while adjusting the film thickness.

Next, the cloth 2 set in a roll is sent onto the vinyl chloride paste resin RB and pressed, so that the vinyl chloride paste resin RB permeates into the surface of the cloth 2. Thereafter, the vinyl chloride paste resin RB to which a foaming agent has been added is heated with an infrared heater 8 to foam (the foaming agent reacts) and harden, forming an integral layer of the foam 3 on the surface of the cloth 2. do. At the same time, the vinyl chloride paste resin RA also progresses in curing. With the above, decoration layer 4
A foam sheet 1 with an attached shape is formed on the release paper 6.

Next, in order to provide the foam sheet 1 on the surface of the center pillar interior material, the release paper 6 is peeled off from the decoration layer 4, and the foam sheet 1 with the decoration layer 4 is made larger to correspond to the shape of the interior material. After trimming, as shown in FIG. 4, it is set in a movable mold 15 of an injection molding apparatus so that the decorative layer 4 faces the mold surface side. Subsequently, as shown in FIG. 5, the movable mold 15 and the fixed mold 1
6 is molded and injection molded with molten PP resin, the foam sheet 1 and the decorative layer 4 are pressed against the mold surface of the movable mold 15 by injection pressure, and at the same time, the base material 5 is placed on the back surface of the cloth 2. are integrally formed.

In the embodiment configured as described above, the vinyl chloride paste resin foam 3 is formed on the surface of the cloth 2, and at the same time, the foam 3 and the cloth 2 are integrated. Therefore, the process of forming the foam 3 and the process of joining the foam 3 to the cloth 2 are integrated into one, which simplifies the manufacturing process as a whole and contributes to cost reduction.

In addition, since the vinyl chloride paste resin RB penetrates into the surface of the cloth 2 and captures the fibers or threads of the cloth, the foam 3 is firmly attached to the cloth 2 with a mechanical anchor effect, and the bonding sex becomes extremely high. Therefore, the foam 3 will not peel off from the cloth 2 due to the heat and pressure during the injection molding.

Furthermore, in this embodiment, vinyl chloride paste resin is also used for the decorative layer 4, and its formation and bonding to the foam body 3 are performed simultaneously, thereby simplifying the process and improving bondability. In addition, this decorative layer 4
protects the foam 3 while improving its appearance.

Note that foams using non-crosslinked vinyl chloride paste resin do not have very high elongation or tensile strength at high temperatures. Therefore, during the injection molding process, there remains a possibility that the foam may be damaged at stress concentration areas such as near the gate or at corners, or may be partially melted and peeled off from the cloth 2. Furthermore, the heat resistance and durability of the foam after the molded product is completed are not high.

However, in this example, the foam 3 made of cross-linked vinyl chloride paste resin is used, so it has excellent elongation and tensile strength properties at high temperatures, and there is no problem of breakage or peeling during injection. It also has high heat resistance and durability after the molded product is completed. This also applies to the decorative layer 4.

In order to confirm the effect of the above-mentioned cross-linked type, a cross-linked type vinyl chloride paste resin and a non-cross-linked type vinyl chloride paste resin were blended as shown below, and both were mixed at a ratio of 100:0, 80:20, 60:40, respectively.
They were mixed at a ratio of 40:60, 20:80, or 0:100, and the elongation and tensile strength at a high temperature of 130°C were measured.

[Crosslinked vinyl chloride paste resin] Vinyl chloride copolymer (manufactured by Mitsubishi Monsanto, trade name P100) 100 parts by weight Phthalate plasticizer 90 parts by weight Organotin stabilizer 3 parts by weight Epoxy stabilizer 3 parts by weight Partially crosslinked isocyanate (manufactured by Takeda Pharmaceutical Co., Ltd., trade name B815N) 8 parts by weight [non-crosslinked vinyl chloride paste resin] Vinyl chloride copolymer (manufactured by Mitsubishi Monsanto, trade name P470) 100 parts by weight Phthalate ester plasticizer Agent 75 parts by weight Organotin stabilizer 3 parts by weight Epoxy stabilizer 3 parts by weight The elongation test results at a high temperature of 130°C are shown in FIG. 6, and the tensile strength test results are shown in FIG. As is clear from the figure, both elongation and strength significantly improved as the crosslinked type mixture ratio increased, and it was confirmed that this was effective in preventing breakage and peeling during injection molding.

In addition to the above-mentioned effects, this embodiment also provides the following effects. In other words, during injection molding
Since the cloth 2 blocks the heat of the PP resin, the foam 3 is prevented from melting and being damaged.

In addition, since the fabric 2 is firmly bonded to the base material 5 by mechanical anchoring effect or fusion, the foam sheet 1 will not peel off from the base material 5 or be damaged even if some external force is applied. There is no. In particular, since PP resin, which is one of the polyolefin resins, does not have polar groups and has low adhesive properties, this embodiment is effective because it can provide high bonding strength without using an adhesive.

In addition, the PP resin that has penetrated into cloth 2 is foamed sheet 1.
Since it is hidden by the decorative layer 4, the cloth 2 may be a cloth (whether woven or non-woven) having any grain, thickness, density, yarn type, etc.

Note that the present invention is not limited to the configuration of the embodiment described above, and can be embodied as follows, for example.

(1) The blending ratio of the vinyl chloride paste resin forming the foam 3 is not limited as long as it is in a sol paste state before being heated and hardened.

(2) For example, the material, formation method, etc. of the decorative layer 4 may be changed as follows.

Another Example 1 As shown in FIG. 8, pile flocking is applied as a decorative layer 20 to the surface of the foam 3 after formation.

Another Example 2 As shown in FIG. 9, a cloth is bonded to the surface of the foam 3 as a decorative layer 21.
This decorative layer 21 can be bonded to the foam 3 by adhering it to the vinyl chloride paste resin in the paste state of the foam 3.

Other example 3 As shown in FIG. 10, decorative layer 2
2. Use a sheet made of various synthetic resins such as polypropylene, urethane, polyethylene, etc. The difference from the previous embodiment is that a preformed sheet is adhered to the foam 3 with an adhesive 23 or heat-sealed.

Other Example 4 As shown in Figure 11, foam 3
A decorative layer 24 constituting colors, letters, patterns, etc. is provided on the surface by printing, and a protective coating film 25 is formed by applying acrylic paint or the like on the surface. Note that the decorative layer 24 is not only printed, but also
Any method such as painting, sputtering, coating, etc. that can form a thin layer for decoration may be used.

Other Example 5 As shown in FIG. 12, decorative layer 2
6, providing an uneven portion on the surface of the foam 3.

(3) As mentioned above, the cloth 2 is not limited to a plain woven cloth made of polyester fiber yarn, but can be any cloth (whether woven or nonwoven) having any grain, thickness, density, yarn type, etc. May be used. This texture,
The degree of penetration of the synthetic resin varies depending on the thickness, density, etc., and when a nonwoven fabric is used, the synthetic resin will penetrate between the fibers. Furthermore, the presence or absence of fusion with the synthetic resin and the degree of fusion differ depending on conditions such as the type of thread and the injection temperature.

(4) By raising the back surface of the cloth 2, the anchoring effect of the foam 3 and the base material 5 to the cloth 2 is enhanced, and the bondability can be further improved.

(5) The synthetic resin constituting the base material 5 is not limited to the above-mentioned PP resin, but may include polyethylene (PE) resin, polystyrene (PS) resin, ABS resin, methyl methacrylate (PMMA) resin, polyurethane resin, and other various synthetic resins. can be used arbitrarily.

In particular, when using polyolefin resins such as PP resins and PE resins that do not have polar groups and have low adhesive properties, the present invention is effective because high bonding strength can be obtained even without an adhesive.

(6) Since the foam sheet of the present invention has excellent heat resistance,
It is suitable not only when a synthetic resin is injection molded on the back surface, but also when vacuum forming, blow molding a synthetic resin on the back surface, or adhering a hot melt type adhesive.

(6) In this specification, the term injection molding means a comprehensive injection molding including reaction injection molding.

(7) In addition to center pillar interior products, this invention also provides
Automotive interior products such as car door linings, ceiling materials, and instrument panels, as well as furniture,
It can be embodied as a foam sheet provided on the surface of various resin molded products such as fittings and wall materials.

Effects of the Invention The foamed sheet of the present invention has the following excellent effects.

The foam is firmly attached to the fabric due to its mechanical anchoring effect, and its bondability is extremely high. Furthermore, isocyanate-crosslinked or triazine-crosslinked vinyl chloride paste resin foams have particularly excellent elongation, elongation, and tensile strength properties at high temperatures.

Further, when a foam sheet is vacuum formed, or when a synthetic resin is injection molded, blow molded, or vacuum formed on the back side of the foam sheet, the cloth blocks the heat during the molding.

Therefore, the foam is hardly peeled off from the cloth or damaged by the heat and pressure during the molding process. In particular, the above-mentioned damage and peeling can be prevented even in stress concentrated parts such as corner parts of the foam sheet and in the vicinity of gates in injection molding.

Further, the decorative layer provided on the surface of the foam improves the appearance and protects the foam at the same time.

Furthermore, the manufacturing process is simplified, contributing to cost reduction.

[Brief explanation of drawings]

1 to 7 show one embodiment of a foam sheet embodying the present invention, FIG. 1 is a cross-sectional view of the same embodiment provided on the surface of an automobile center pillar, and FIG.
The figure is also an enlarged sectional view, Figure 3 is a schematic diagram showing the method of manufacturing the foam sheet, Figure 4 is a sectional view showing the state before mold matching during injection molding, and Figure 5 is the same state after mold matching. FIG. 6 is a relationship diagram showing the relationship between the mixing ratio and elongation of vinyl chloride paste resin, FIG. 7 is a relationship diagram showing the relationship between the mixing ratio and tensile strength of vinyl chloride paste resin, and FIG. 9 is a sectional view showing another example 2 of the embodiment, FIG. 10 is a sectional view showing another example 3, and FIG. 11 is a sectional view showing another example 4. , 12th
The figure is a sectional view showing another example 5. Foam sheet...1, cloth...2, vinyl chloride paste resin foam...3, decorative layer...4.

Claims (1)

[Claims] 1. An isocyanate-crosslinked or triazine-crosslinked vinyl chloride paste resin foam is integrally laminated on the surface of the cloth, and a decorative layer is provided on the surface of the vinyl chloride paste resin foam. foam sheet.