JPH06115021A - Thermoforming sheet material and formed object - Google Patents

Abstract

PURPOSE:To obtain a thermoforming sheet material having a low shrinkage factor after forming and a little glossiness change before and after forming and realizing an enhanced grain retention and to make a formed object out of this sheet material. CONSTITUTION:A polymer forming a sheet layer is composed of a composition obtained by compounding at least one kind of polymer (B) by 0-2000 pts.wt. per 100 pts.wt. of one or more kinds of graft polymer (A): (A) is a graft polymer obtained by forming 95-5 pts.wt. polymer as a branch made of at least one kind of monomer selected out of styrene, alpha-methylstyrene, and acrylonitrile on 5-95 pts.wt. olefin polymer serving as a backbone; (B) is a polymer selected out of a thermoplastic olefin elastomer, a thermoplastic olefin rubber, and a thermoplastic olefin resin. A sheet forming the sheet layer formed by this composition has a 10% modulus at 20 deg.C of 5-250kgf/cm<2> (a dumbbell No.1, a tensile speed of 50mm/min).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-molded sheet-like article and a molded article formed by using the sheet-like article, and more particularly to a sheet-like article such as a vacuum forming method, a press forming method and a stamping forming method. The present invention relates to a sheet-like material used in a heat-molding method for heat-molding and a molded article formed by the above-mentioned heat-molding method using the sheet-like material as a skin layer.

[0002]

2. Description of the Related Art Sheet-like materials used for instrument panel pads as automobile interior materials and door skin trim layers have hitherto been formed of vinyl chloride resin or a blend of vinyl chloride resin and ABS resin. Items are commonly used.

In recent years, PVC removal due to environmental problems, weight reduction,
Thermoplastic olefin-based elastomers are attracting attention as alternative materials for vinyl chloride resins due to needs such as recycling.

In general, an instrument panel pad is obtained by heating a sheet-like material, which has been previously squeezed on the surface, to a predetermined temperature, for example, around 160 ° C., and forming a skin layer by a vacuum molding method using a male mold. It is manufactured by pouring and foaming semi-rigid urethane between the layer and the core.

In general, door trims have a back surface laminated with a foam material, and a sheet-like material which is previously squeezed on the front surface is heated to a predetermined temperature, for example, about 160 ° C., and an adhesive is applied to the core. The material is set in a male mold, and the sheet-like material is vacuum-molded and integrated with the material to manufacture.

[0006]

However, in the case of a sheet-like material using a thermoplastic olefin-based elastomer, (1) the shrinkage rate after molding is high, and it is difficult to secure a desired dimensional accuracy. 2) It is difficult to secure the desired gloss because the change in gloss before and after molding is large.
Further, (3) there is a drawback in that draw flow easily occurs during molding, and it is difficult to maintain a desired draw shape, that is, it is difficult to improve undrawing.

These drawbacks will be further explained below. (1) Mold Shrinkage For example, when molding an instrument panel pad, the vacuum mold (male) is made larger than the foam mold in which semi-rigid urethane is injected in consideration of the mold shrinkage of the skin. For example, when the sheet material is switched by using a vacuum molding die (male die) that is commonly used at present, if the difference in shrinkage rate due to the sheet material is large, the dimensions will not match when set in the foaming die. Occurs, and the sharpness of the edge part is reduced, and there are problems such as excessive wrinkles on the skin. Generally to fix this,
The dimensions of the vacuum forming mold (male mold) are modified, but when the modification amount is large, both the time and cost required for the modification are large. For this reason, for example, when a mold used for molding a sheet-shaped material made of a vinyl chloride resin or a sheet-shaped material made of a blend of a vinyl chloride resin and an ABS resin is used, the molding shrinkage ratio of the skin is October 100
It is desired to be 0 (mm / mm) or less. However, up to now, the sheet-like material using the thermoplastic olefin elastomer has not been able to satisfy this.

(2) Glossiness Generally, the glossiness of the surface changes before and after molding, but the glossiness after molding is desired to be about 2.0 or less. To achieve this, a method of adjusting the glossiness by a surface treatment agent applied to the surface of the epidermis is generally used.
However, this method also has a limit of adjustment due to the influence of the properties of the sheet layer itself, and up to now, the sheet-like material using the thermoplastic olefin elastomer has a large change in gloss before and after the molding, and depending on the surface treatment agent. It was often difficult to adjust the gloss level.

(3) Non-squeezing Unstrained sheet-like material is heated to soften it and then molded, and then cooled and demolded to obtain a desired shape. By heating, expanding into a desired shape and stretching during molding, so-called throttling occurs, such as a reduction in the depth of the drawing or a change in the appearance of the drawing. Things are desired. It is considered that such throttle flow is due to the characteristics of the sheet layer during heating, but hitherto, the sheet-like material using the thermoplastic olefin elastomer has not always been able to satisfy the above-mentioned requirements.

In particular, vehicle interior materials are frequently exposed to the eyes of passengers, and the surface appearance is an important performance, and it is desired to satisfy all of the above (1) to (3). However, the same is also desired in the case of molded articles such as bags and daily sundries obtained by heat molding.

The object of the present invention is to solve the above-mentioned problems of the prior art, to reduce the shrinkage ratio after molding, to reduce the change in glossiness before and after molding, and to improve the unpressed portion. An object of the present invention is to provide a molded product obtained by heat molding such as a vacuum molding method using the molded product and the sheet-shaped product.

[0012]

DISCLOSURE OF THE INVENTION The present inventors have described the above-mentioned (1) for a sheet-like article using a thermoplastic olefin elastomer in a thermoforming method including vacuum forming.
The present invention has been achieved as a result of extensive studies to solve the problems (3) to (3).

That is, in the sheet material for thermoforming of the present invention, the polymer component of the portion constituting the sheet layer in the sheet material is (A) 5 to 95 parts by weight of the olefin polymer serving as the trunk. ,
One or two or more graft polymers in which 95 to 5 parts by weight of a branched polymer composed of at least one monomer selected from styrene, α-methylstyrene, and acrylonitrile is formed: 100 parts by weight (B) heat A composition comprising at least one polymer selected from a plastic olefin elastomer, a thermoplastic olefin rubber, or a thermoplastic olefin resin: 0 to 2000 parts by weight, and constituting the sheet layer prepared from this composition Sheet has a 10% modulus value at 20 ° C. of 5 kgf / cm ^{2 to} 250 kgf / cm
² (dumbbell No. 1, pulling speed 50 mm / min). Further, the molded product of the present invention is a molded product molded by a heat molding method such as a vacuum molding method using a sheet-like material composed of the polymer component of the above composition.

In the present invention, the graft polymer component (A) forming the sheet layer portion of the sheet material for thermoforming is
It is a graft polymer in which a branch polymer composed of at least one monomer selected from styrene, α-methylstyrene, and acrylonitrile is formed on an olefin polymer serving as a backbone.

The olefinic polymer serving as the trunk in the graft polymer component (A) has a function of providing compatibility with the component (B), and may be any polymer capable of forming a polymer serving as a branch. However, homopolymers of ethylene, propylene and the like, ethylene, propylene and α-olefins having 4 to 10 carbon atoms (eg 1-butene, isobutylene, 4
-Methyl-1-pentene, etc.) and ethylene-propylene-diene copolymers are exemplified, and these can be used alone or in combination.

The branch polymer in the graft polymer component (A) includes a polymer composed of one monomer selected from styrene, α-methylstyrene and acrylonitrile, and a polymer composed of two or more monomers. The polymer composed of two or more kinds of the monomers may be either a random copolymer or a block copolymer. The polymer as a branch in these (A) graft polymer components is
Originally, it is incompatible with the polymer component (B), but is made compatible with the polymer component (B) by making it a graft polymer with the olefin polymer as the backbone. Therefore, it has an effect of compensating for the drawbacks of the conventional thermoplastic olefin elastomers.

The ratio of the polymer serving as the trunk to the polymer serving as the branch is 5 to 95 parts by weight, preferably 20 to 90 parts by weight, of the olefin polymer serving as the trunk, and styrene, α-methylstyrene and acrylonitrile. It is preferable that the amount of the branched polymer composed of at least one monomer selected from the above is 95 to 5 parts by weight, preferably 80 to 10 parts by weight.
When the amount of the olefinic polymer serving as the trunk is less than 5 parts by weight,
The compatibility with the polymer component (B) becomes poor, the polymer component (B) is not sufficiently mixed, and a sheet having satisfactory physical properties cannot be obtained. When the amount of the olefinic polymer serving as the backbone exceeds 95 parts by weight, the shrinkage ratio after molding, the change in glossiness before and after molding, which is the object of the present invention when the sheet material for heat molding is molded, and after molding Is not satisfied.

Graft polymers generally include polymers in which the polymer to be branched is not bound to the backbone polymer, unless otherwise purified. The graft polymer as used in the present invention may be one in which the polymer to be a branch contains a polymer which is not bonded to the polymer serving as the trunk.

In the present invention, the polymer component (B) forming the sheet layer portion of the sheet material for thermoforming is a thermoplastic olefin elastomer, a thermoplastic olefin rubber,
Alternatively, it is made of at least one polymer selected from thermoplastic olefin resins. The thermoplastic olefin elastomer in the polymer component (B) is ethylene-α-, which is known in Japanese Patent Publication No. 53-21021.
Temporary kneading mixture of partially crosslinked olefin copolymer rubber and olefin resin, partially kneaded partially crosslinked ethylene-α-olefin and olefin resin known in JP-B-53-34210, known in JP-B-62-59139. Examples thereof include a partially co-crosslinked product of the ethylene-α-olefin copolymer rubber and an ethylene resin, a mixture of a rubber-like material, an olefin resin and the like.

The thermoplastic olefin rubber in the polymer component (B) is ethylene-propylene copolymer rubber or ethylene-propylene rubber.
Propylene-non-conjugated diene copolymer rubber, polyisobutylene, butyl rubber, propylene-1-butene copolymer rubber,
Hydrogenated styrene-butadiene copolymer rubber and the like are exemplified.

The thermoplastic olefin resin in the polymer component (B) is ethylene, propylene, or C4-10.
Α-olefins such as 1-butene, 4-methyl-
Homopolymers or copolymers such as 1-pentene, ethylene or propylene as a main component, other monomers copolymerizable with these (for example vinyl acetate, acrylic acid ester,
Examples thereof include copolymers with methacrylic acid esters and the like). By adding the above-mentioned polymer component (B) to the graft polymer (A), it is possible to improve the sheet processability by extrusion processing and the like and to improve the physical properties such as tear strength, and at the same time, under vacuum forming. The sheet elongation becomes high, and the sheet can be prevented from breaking.

In the present invention, the graft polymer component (A)
The polymer component (B) is blended in an amount of 0 to 2000 parts by weight, preferably 10 to 1500 parts by weight, and more preferably 20 to 1000 parts by weight with respect to 100 parts by weight. The amount of the polymer component (B) is 20 per 100 parts by weight of the graft polymer component (A).
When the amount is more than 00 parts by weight, the shrinkage ratio after molding, the change in glossiness before and after molding, and the unsqueezed residue after molding when the sheet material for thermoforming which is the object of the present invention is not satisfied.

Next, 20 sheets of the sheet prepared from the composition in which the graft polymer component (A) and the polymer component (B) were blended
10% modulus value at 5 ° C is 5 kgf / cm ² to 2
50kgf / cm ² (Dumbbell No. 1, pulling speed 50m
m / min), preferably 10 kgf / cm ^{2 to} 20
It should be 0 kgf / cm ² . 1 mentioned above
A sheet made of a polymer component composition having a 0% modulus value of less than 5 kgf / cm ² was inferior in processability during sheet production, while it was made of a polymer component composition of more than 250 kgf / cm ² . In the case of a sheet, the molded body is too hard to obtain the desired molded body.

In the present invention, in addition to the above-mentioned graft polymer component (A) and polymer component (B), another polymer (C) may be mixed if necessary. ) Can be selected from those that are compatible with the polymer that forms the branch of the graft polymer. Examples of such a polymer (C) include an acrylonitrile-styrene copolymer and an acrylonitrile-butadiene-styrene copolymer. The mixing ratio of the polymer (C) should be determined in consideration of the compatibility with the composition of the graft polymer component (A) and the polymer component (B), and is not uniquely determined, but the graft 50 parts by weight or less may be used per 100 parts by weight of the composition of the polymer component (A) and the polymer component (B).

In the present invention, in addition to the above-mentioned graft polymer component (A) and polymer component (B) and, if necessary, the polymer (C), it is necessary to improve the properties of each molded product. Arbitrary components can be added accordingly. Examples of the optional component include an ultraviolet absorber, an antistatic agent, a flame retardant, a filler, an antioxidant, a light resistance stabilizer, and a colorant.

The sheet-like product of the present invention is obtained by subjecting a sheet formed by extrusion molding, calender molding or the like containing the above-mentioned polymer component to the surface with the primer and the surface to the surface, and the back surface with the primer. The back surface is treated or the back surface is laminated with PP foam or the like.
The molded product of the present invention is a molded product molded by a heat molding method such as vacuum molding using the above-mentioned sheet material, and is used as a vacuum molded product for automobile interior, for example, instrument panel pad, door trim, etc. However, it can be applied as other automobile interior materials, for example, automobile interior materials such as ceilings, pillars, console boxes, glove boxes and the like. The present invention is not limited to automobile interior materials, vacuum forming method, press forming method,
Alternatively, the present invention can be applied to a bag molded by a heat molding method such as a stamping molding method, a sheet-like article for daily sundries, and a molded article having the sheet-like article as a skin layer.

Although the sheet using the thermoplastic olefin elastomer generally has poor adhesiveness, the sheet according to the present invention also has the effect of improving the adhesiveness.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention and is a cross-sectional view of a main part of an instrument panel pad as a vacuum molded body for automobile interior. In FIG. 1, a surface treatment layer 3 is formed on the surface of the sheet layer 1 via a primer layer 2, and a back surface treatment layer 5 is formed on the back surface of the sheet layer 1 via a primer layer 4.

The primer layer 2 includes a polyolefin-based primer agent such as chlorinated polypropylene, polyester-based /
It is possible to use a two-component curing type primer agent of isocyanate, a blend type primer agent of polyolefin type and polyester type / isocyanate, and the like. For the surface treatment layer 3, a urethane surface treatment agent or a vinyl chloride / acrylic surface treatment agent can be used.

The primer agent used for the primer layer 4 can be applied to the primer layer 2 and the back surface treatment agent used for the back surface treatment layer 5 can be the surface treatment agent usable for the surface treatment layer 3. Can be applied,
These may be different from each other. The back surface treatment layer has the function of improving the adhesiveness with the semi-hard urethane injected and foamed.

FIG. 2 shows another embodiment of the present invention and is a cross-sectional view of a main part of a door trim as a vacuum molded body for automobile interior. In FIG. 2, the surface treatment layer 8 is formed on the surface of the sheet layer 6 with the primer layer 7 interposed therebetween.
A PP foam 9 is attached to the back side of the.

Next, an example of manufacturing the instrument panel pad will be described with reference to FIG. The sheet is formed into a sheet having a thickness of 0.6 to 1.2 mm by a calender molding method, a T-die molding method, or the like. After that, the primer layer 2, the surface treatment layer 3, the primer layer 4, and the back surface treatment layer 5 are formed on the sheet layer 1 by gravure or spray processing,
Squeezing is performed in the pressing step, and then the skin layer is vacuum formed by the convex vacuum forming method, and semi-rigid urethane is injected and foamed between the skin layer and the core material to obtain an integrated body. At this time, the primer layer 2 and the surface treatment layer 3 may be formed by a spraying process after being pressed by a pressing process.

An example of manufacturing door trim will be described with reference to FIG. The primer layer 7 and the surface treatment layer 8 were formed on the sheet layer 6 by gravure processing, and the PP foam 9 was laminated at the same time as it was squeezed by a squeezing step, and then an adhesive was previously applied by a convex drawing vacuum forming method. A vacuum molded body that is bonded and integrated with the core material is obtained. At this time, the primer layer 7 and the surface treatment layer 8 may be formed by a spray process after the pressing process.

Examples 1 to 6 and Comparative Examples 1 to 4 Sheets having the compositions shown in Table 1, Table 3 and Table 5 were prepared. The sheet-like materials in Tables 1 and 3 were evaluated for shrinkage, glossiness, drawing depth, workability, and hardness after convex vacuum forming, and the results are shown in Tables 2 and 4. With respect to the sheet-like material in Table 5, the workability and hardness were evaluated, and the results are shown in Table 6. The sheet uses a different direction twin screw extruder,
Cylinder temperature: 170-210 ° C, T-die temperature: 200
~ 210 ° C, sheet thickness: 0.85 mm, sheet width: 11
Extrusion molding was performed under the condition of 00 mm, a polyolefin-based primer agent was applied to both surfaces thereof, a urethane-based surface treatment agent was applied as a surface treatment, and a urethane-based backside treatment agent was used for backside treatment.

The processing conditions are as follows. Gravure roll is used and the application amount is about 20g / wet.
m ² , drying conditions: 120 ° C x 1 minute, 2 times on front side, 2 on back side
The treatment was performed 4 times in total. In addition, drying was performed after each coating process. Then, the sheet was pressed under normal conditions to obtain a sheet with a diaphragm.

Measurement of shrinkage ratio A box-shaped vacuum mold having a length of 300 mm, a width of 600 mm, and a depth of 100 mm is provided with marks at intervals of 200 mm on each of the length and width, vacuum-molded at each surface temperature, and 20 hours after the molding. Measure the distance X between the marks. The shrinkage rate (mm / mm) of each sample is measured three times, and the average value is taken.

Measurement of glossiness A 60 ° glossiness of each sample was measured three times using a digital variable angle glossmeter (Suga Test Co., Ltd.), and the average value was taken.

Measurement of drawing depth A stylus type surface roughness profile measuring machine (Tokyo Seimitsu Co., Ltd.) was used and expressed in Rt (maximum height of roughness curve) μm. The Rt of each sample is measured three times using the same position of the diaphragm pattern as the measurement point, and the average value is taken. Measurement length: 4.0 mm, cut-off value: 0.8 mm, Rt = f (x) max-f (x)
It was calculated from the formula of min.

[0039] indicates the thermoforming processability during extrusion and during post-processing by the processing of different direction twin-screw extruder, in the table ○: heat molding on without hindrance, ×: each case substantially sheet can not be formed Shows.

Hardness The hardness by touch including the touch of the molded body after vacuum molding is shown. In the table, ◯: good hardness, ×: too hard and poor feeling.

[0041]

[Table 1]

MODIPER AT31 as graft polymer
7 (NOF CORPORATION) was used. This content is ethylene
Propylene copolymer rubber (EPR) EPO7P (Japan Synthetic Rubber Co., Ltd.) and acrylonitrile (AN) / styrene (St) ratio 70/30 (weight ratio), acrylonitrile (AN) / styrene (St) ratio 30/70 (weight) ratio)
Is a graft polymer. Thermoplastic Olefin Eras
MILASTOMER 8030N as Tomah (Mitsui Petrochemical Industries, Ltd.), ULTZEX 2021L as the thermoplastic olefin resin A (Mitsui Petrochemical Industries, Ltd.), thermal Friendly
As the plastic olefin resin B , Hipol J440 (Mitsui Petrochemical Industry Co., Ltd.) was used.

[0043]

[Table 2] Examples 1 to 3 shown in Table 2 have a shrinkage ratio as compared with Comparative Example 1,
It can be seen that both the glossiness and the aperture depth performance are excellent.

[0044]

[Table 3]

MODIPER AT37 as graft polymer
4 (Nippon Yushi Co., Ltd.) was used. This content is polypropylene (PP) Nobrene S131 (Sumitomo Chemical Co., Ltd.) and acrylonitrile (AN) styrene (S
t) Ratio 70/30 (weight ratio), acrylonitrile (A
It is a graft polymer having an N) / styrene (St) ratio of 30/70 (weight ratio). Thermoplastic olefin elastomer
MILASTOMER 6030N as chromatography (Mitsui Petrochemical Industries, Ltd.), Sumikasen -LFA201-0 thermoplastic olefin resin A (Sumitomo Chemical Co.), thermoplastic
Hypol B240 (Mitsui Petrochemical Industry Co., Ltd.) was used as the polymerizable olefin resin B.

[0046]

[Table 4] Examples 4 to 6 shown in Table 4 are compared with Comparative Example 2 in shrinkage rate,
It can be seen that both the glossiness and the aperture depth performance are excellent.

[0047]

[Table 5] MODIPER AT317 (NOF CORPORATION) as graft polymer A and MODIPER AT3 as graft polymer B
74 (Nippon Oil & Fats Co., Ltd.), Lavalon SJ4400 (Mitsubishi Petrochemical Co., Ltd.) as the thermoplastic olefin rubber, and Hypol J900 (Mitsui Petrochemical Industry Co., Ltd.) as the thermoplastic olefin resin.

[0048]

[Table 6] In each of Comparative Example 3 and Comparative Example 4 shown in Table 6, the modulus value in the present invention is 5 kgf / cm ^{2 to} 250 kgf.
/ Cm ² is out of the range, and in Comparative Example 3, it is difficult to control the tension, and it is impossible to obtain a sheet having a uniform width and thickness, and there is a problem in either processability or hardness. ing.

[0049]

As described above, according to the present invention, the shrinkage ratio after molding is small, and the change in the surface gloss before and after molding is small,
In addition, it is possible to provide a heat-molding sheet-like product which can improve the unrestrictedness and give a high-grade feeling to the surface, and a molded product obtained by heat-molding such as a vacuum forming method using this sheet-like product.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of an instrument panel pad skin layer according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of a skin layer of a door trim showing another embodiment of the present invention.

[Explanation of symbols]

 1,6 sheet layer 2,4,7 primer layer 3,8 surface treatment layer 5 back surface treatment layer 9 PP foam

Front Page Continuation (72) Inventor Keiichi Hasegawa 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd.

Claims (5)

[Claims] 1. A thermoformable sheet having a multi-layer structure, wherein the polymer component in the part constituting the sheet layer is (A) 5 to 95 parts by weight of an olefin polymer serving as a trunk,
One or two or more graft polymers in which 95 to 5 parts by weight of a branched polymer composed of at least one monomer selected from styrene, α-methylstyrene, and acrylonitrile is formed: 100 parts by weight (B) heat At least one polymer selected from a plastic olefin elastomer, a thermoplastic olefin rubber or a thermoplastic olefin resin: a composition comprising 0 to 2000 parts by weight, and constituting the sheet layer prepared from the composition 10% modulus value at 20 ° C. of the sheet ^{5kgf / cm 2 ~250kgf / cm 2} ( dumbbell No. 1, a tensile rate of 50 mm / min) heating the molding sheet, which is a. 2. The olefin polymer serving as a backbone is a homopolymer or copolymer of an olefin monomer.
Sheet material for heat molding of. 3. The sheet material for thermoforming according to claim 1, wherein the olefin polymer serving as a backbone is a mixture of a homopolymer and / or a copolymer of olefin monomers. 4. The sheet material for thermoforming according to claim 2, wherein the olefinic monomer is selected from ethylene, propylene, and α-olefins having 4 to 10 carbon atoms. 5. A molded article, which has a decorated surface of the sheet-like article according to claim 1 and which has a laminated structure forming a skin layer.