JPH06234176A - Laminated composite - Google Patents

Abstract

PURPOSE:To provide a laminated composite wherein a polyolefin resin foamed body having excellent toughness and softness at its surface layer is excellently adhered to a surface skin material. CONSTITUTION:A laminated composite is made of a polyolefin resin foamed body and a surface skin material. In the polyolefin resin foamed body, an apparent density is 0.02-0.2g/cm<3>, a xylene extraction residual value at 120 deg.C is 20-80wt.%, an average diameter (a) in the direction of thickness of all the foams within 0.8mm from the surface is 0.05-1mm, and the number of foams whose diameters in the thickness direction are within + or -15% of the average diameter (a) is 80% or more of all the foams. Accordingly, a molded piece having toughness and softness at the surface layer of the foamed body, which is adhered to the surface skin material excellently without expansion and wrinkle at its surface, can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated composite comprising a polyolefin resin foam and a skin material, and more specifically, a polyolefin resin foam excellent in strength and flexibility of the surface layer portion can be used as a skin material. The present invention relates to a laminated composite that is adhered.

[0002]

2. Description of the Related Art Polyolefin-based resin foams are excellent in flexibility and heat insulation and have been conventionally used as interior materials for vehicles such as ceilings, doors and instrument panels. These interior materials are mainly polyolefin resin foams, laminated with polyvinyl chloride resin sheets, thermoplastic elastomer sheets, cloth-like materials, skin materials such as leather, and molded by vacuum molding, compression molding or the like. When the strength of the surface layer portion of the foam is insufficient, the foam often breaks, and when the adhesiveness between the foam and the skin material is low, the surface of the obtained interior material swells and wrinkles often occur. .

Therefore, in order to improve the strength of the surface layer of the foam, Japanese Patent Laid-Open No. 1-222937 proposes a foam in which the expansion ratio of the surface layer of the surface laminated with the skin material is increased. Japanese Patent Publication No. 57-26207 proposes a method for producing a foam having an increased degree of cross-linking in the surface layer. In both cases, the strength of the surface layer is improved, but it is too hard and the flexibility of the foam is reduced. There is a drawback that it does.

Further, in order to improve the adhesiveness between the foam and the skin material, in JP-A-62-190235, there is manufactured a polyethylene resin foam in which the average value of the diameters of the cells in the thickness direction is limited. A method has been proposed and is disclosed in JP-A 1-2229
In JP-A No. 29-29632, there is proposed a polyolefin-based resin foam in which the diameter of the bubbles in the thickness direction is compressed by being compressed in the thickness direction, and a manufacturing method thereof. In JP-A-3-62832, a length direction and a width are proposed. Although a polyolefin resin foam in which the diameter in the thickness direction of the cells is contracted by stretching in the direction and a method for producing the same has been proposed, although the adhesion to the skin material is improved, the surface layer portion of the foam is also proposed. Has the disadvantage that its strength is insufficient.

[0005]

In view of the above drawbacks, the present invention provides a laminated composite in which a polyolefin resin foam excellent in strength and flexibility of the surface layer portion is well adhered to the surface material. The purpose is to

[0006]

Since the apparent density of the polyolefin resin foam used in the present invention decreases, the strength of the surface layer portion of the foam decreases, and when the apparent density decreases, the flexibility of the foam decreases. 0.02-0.2g / cm ³
Limited to

When the xylene extraction residue value at 120 ° C. of the foam decreases, the strength of the surface layer of the foam decreases, and when it increases, the flexibility of the foam decreases.
It is limited to 0 to 80% by weight.

The above residual value was obtained by collecting 0.1 g of the foam, crushing the bubbles, maintaining the mixture in 50 ml of xylene at a temperature of 120 ° C. for 24 hours, and then allowing it to pass through a wire mesh of 200 mesh to obtain a dry weight of the residue. (G) is weighed and calculated by the following equation (3). Residual value (% by weight) = (dry weight of residue / 0.1) × 100 (3)

If the average value (a) of the diameters in the thickness direction of all the cells, the center of which is located in the surface layer within 0.8 mm from the surface on the side laminated with the skin material in the above-mentioned foam, becomes smaller, it becomes adjacent. Since the gap between the cells is reduced and the strength of the surface layer portion is reduced, and when the gap is increased, a portion with a large gap and a portion with a small gap are partially formed and the flexibility of the foam is reduced.
It is limited to 05 to 1 mm. The shape of the bubbles may be the same not only on the side laminated with the skin material but also on the surface layer portion on the opposite side.

As a method of controlling the size of the bubbles, for example, a method of adding a thermal decomposition type foaming agent and free-foaming the resin in a foaming furnace heated to a predetermined temperature higher than the decomposition temperature thereof can be mentioned. In the case of using azocarbonamide as an example, the thermal decomposition rate becomes slower and the bubbles become smaller when the temperature becomes lower, and the thermal decomposition rate becomes faster and the bubbles become larger when the temperature becomes higher. , And more preferably 215 to 250 ° C.

Of all the bubbles whose center is located on the surface layer, the diameter in the thickness direction is ± 15% of the average value (a).
If the number of cells within the range is smaller, the flexibility of the foam decreases, so it is limited to 80% or more.

As a method for making the sizes of the bubbles uniform,
For example, there is a method of foaming a resin by using a pyrolytic foaming agent having a uniform particle size. When the particle size is smaller, the thermal decomposition rate of the foaming agent is faster and the bubbles are larger, and when it is larger, the thermal decomposition rate is higher. Since the decomposition rate becomes slower and the bubbles become smaller, it is preferably 3 to 14 μm, more preferably 4 to 11
μm.

In addition to the above methods, a method of foaming using a resin that is micro-dispersed and has uniform strength, and a method in which the (meth) acryloyloxy at both ends is preferably carbon number Examples of the method include foaming using a resin uniformly crosslinked with a crosslinking aid such as di (meth) acrylate of an aliphatic dihydric alcohol having 2 to 18 alkylene groups and aromatic polyvalent carboxylic acid allyl ester. .

Further, as a method of controlling the diameter of the bubbles in the thickness direction, for example, when a thermal decomposition type foaming agent is added and the resin is continuously heated and foamed in a foaming furnace, the resin enters the furnace. Examples of the method include a method of winding at a winding speed of a drawing ratio that is relatively small with respect to the speed. When the winding speed becomes slow, the diameter becomes long, and when it becomes fast, the diameter becomes short.
A winding speed of 1 to 5 times is preferable for ~ 2.5 m / sec,
It is more preferably 1.5 to 4 times.

Examples of the material of the polyolefin resin foam include homopolymers of ethylene, propylene, butene, etc .; ethylene, propylene and α having 4 or more carbon atoms.
A copolymer of two or more olefins selected from the group consisting of olefins; ethylene and (meth) acrylic acid,
Examples thereof include a lower alkyl ester of (meth) acrylic acid or a copolymer with vinyl acetate, and these resins may be used alone or in combination.

Examples of the α-olefin having 4 or more carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1pentene, 1-octene and the like.

When the melt index (MI) of the polyolefin resin is small, the moldability of the resin is low, and when it is high, the heat resistance of the foam is low. 1
It is preferably 0 minutes, more preferably 3 to 30 g / 10 minutes. In the case of polypropylene resin, 0.3 to 12
g / 10 minutes is preferable, and more preferably 0.5 to 5 g /
10 minutes.

As a method of foaming the above polyolefin resin, for example, a predetermined amount of polyolefin resin,
A thermoplastic resin, a crosslinking aid, a pyrolytic foaming agent, etc. are supplied to an extruder, melt-kneaded and extruded to obtain a resin sheet, and the obtained resin sheet is irradiated with a predetermined amount of an electron beam to be crosslinked to obtain a resin sheet. A method of supplying the crosslinked sheet thus obtained to a foaming furnace for heating and foaming, a method of supplying the above-mentioned predetermined amount of material to an extruder and foaming with a heating roll simultaneously with extrusion, and supplying the above-mentioned predetermined amount of material to a mold and heating. Then, a conventionally known method such as a method of foaming in a batch system can be used.

Examples of the thermoplastic resin include polyvinyl chloride resin and the like.

Examples of the crosslinking aid include radical generators such as benzoyl peroxide, divinylbenzene, trimethylolpropane tri (meth) acrylate, and 1,6.
-Hexanediol di (meth) acrylate, 1,9-
Examples thereof include polyfunctional monomers such as nonanediol di (meth) acrylate.

Examples of the thermal decomposition type foaming agent include azodicarbonamide, benzenesulfonyl hydrazide,
Dinitrosopentamethylene tetramine, toluene sulfonyl hydrazide, 4,4-oxybis (benzene sulfonyl hydrazide) etc. are mentioned.

The above-mentioned polyolefin-based resin includes phenol-based, phosphorus-based, amine-based, sulfur-based antioxidants, metal-damage-preventing agents, flame-retardants, and fillers as long as the properties of the resulting foam are not impaired. , Antistatic agents, pigments and the like may be added.

As the skin material used in the present invention, conventionally known skin materials can be used, and examples thereof include a polyvinyl chloride resin sheet, a thermoplastic elastomer sheet, a cloth-like material, leather, and the like. It is laminated with the foam by being adhered with an agent or heat laminated.

The foam used in 2 of the present invention has an apparent density of 0.02 to 0.2 g / c as in the invention of 1.
m ^3, 120 xylene extraction residue value at ℃ is 20-8
It is limited to 0% by weight, and the average value (a) in the thickness direction of all the cells whose center is located in the surface layer portion in the foam is 0.05 to
Limited to 1 mm.

Further, in the foam, the average value (a) and the average value (b) and the average value (c) of the diameters in the length direction and the width direction which are orthogonal to the thickness direction are as follows. Formula (1)
And (2) must be satisfied. 0.6 ≦ (a) / (b) ≦ 1.5 (1) 0.6 ≦ (a) / (c) ≦ 1.5 (2)

As the values of (a) / (b) and (a) / (c) become smaller, the strength of the surface layer portion of the foam decreases,
Since the flexibility of the foam decreases as the size increases, both are limited to the ranges of the above formulas (1) and (2).

The values of (a) / (b) and (a) / (c) are controlled by a method of controlling the diameter of the bubbles in the thickness direction. That is, when a thermal decomposition type foaming agent is added and the resin is continuously heated and foamed in a foaming furnace, it is controlled by a method such as winding at a winding speed that is a relatively small draw ratio with respect to the speed at which the resin enters the furnace. To be done.

[0028]

EXAMPLES Next, examples of the present invention will be described. In addition,
"Parts" means "parts by weight". Example 1 (1) Production of foam 80 parts ethylene-propylene copolymer (ethylene content 3% by weight, melt index 1.5 g / 10 min), polyethylene (density 0.935 g / cm ³ , melt index 7 g / 10) Min) 20 parts, 1.5 parts of trimethylolpropane trimethacrylate as a crosslinking aid and 1,9
-1.5 parts of nonanediol dimethacrylate, 10 parts of azodicarbonamide as a thermal decomposition type foaming agent, and 2,6-di-t-butyl-p-cresol 0.3 as an antioxidant.
Parts and 0.3 parts of dilauryl thiopropionate and 0.5 parts of methylbenzotriazole as a metal damage inhibitor are supplied to a single-screw extruder (manufactured by Ikegai Tekko KK, model: PCM-30) at a temperature of 190 ° C. Melt kneading and extruding, thickness 1mm
A resin sheet of was obtained. The resulting resin sheet has an accelerating voltage of 4
Electron beam 4Mrad was irradiated at 00kV to crosslink, and the obtained crosslinked sheet was supplied to a vertical hot air foaming furnace to obtain an internal temperature of 2
A foamed body was obtained by continuously stretching at 70 ° C., an entry speed of 1.6 m / sec and a winding speed of 8 m / sec, and heat-foaming.

(2) Manufacture of Laminated Composite The surface of the obtained foam is subjected to corona discharge treatment, and a two-component curable polyester adhesive (polyester: manufactured by Hitachi Chemical Polymer Co., Ltd., trade name: Hibon; isocyanate: Sumitomo Bayer) Using a urethane company, trade name: Desmodur R), a 0.65 mm-thick vinyl chloride resin and an acrylonitrile-butadiene-styrene copolymer resin mixed sheet were adhered to obtain a laminated composite.

Example 2 A foam obtained in the same manner as in Example 1 had a thickness of 0.65 m.
m was laminated with a thermoplastic polyolefin sheet to obtain a laminated composite.

Examples 3 and 4 Using a predetermined amount (part) of the composition shown in Table 1, a predetermined amount (M
A foam and a laminated composite were obtained in the same manner as in Example 1 except that the electron beam (rad) was applied.

[0032]

[Table 1]

Example 5 A predetermined amount (part) of the composition shown in Table 1 above was supplied to a 6-inch roll and kneaded at a temperature of 170 ° C. and 20 rpm for 5 minutes, and then a press molding machine (manufactured by Shinto Metal Industry Co., Ltd., Model: NSF
-37) was press-molded at a temperature of 180 ° C. and a pressure of 100 kg / cm ² to obtain a resin sheet having a thickness of 1 mm. The obtained resin sheet was irradiated with an electron beam of 3.2 Mrad at an acceleration voltage of 400 kV to be crosslinked, and the obtained crosslinked sheet was placed in an oven and freely foamed at a temperature of 240 ° C. for 6 minutes to obtain a foam. Using the obtained foam, a laminated composite was obtained in the same manner as in Example 1.

Comparative Examples 1 and 2 Using the predetermined amount (part) of the composition shown in Table 2, a predetermined amount (M
A foam and a laminated composite were obtained in the same manner as in Example 1 except that the electron beam (rad) was applied.

[0035]

[Table 2]

Comparative Example 3 The crosslinked sheet obtained in the same manner as in Example 1 was placed in an oven and allowed to freely foam at a temperature of 300 ° C. for 5 minutes to obtain a foam. Using the obtained foam, a laminated composite was obtained in the same manner as in Example 1.

Comparative Example 4 An acceleration voltage of 4 was applied to a resin sheet obtained in the same manner as in Example 1.
Irradiate with electron beam 10 Mrad at 00 kV to crosslink, and put the obtained crosslinked sheet in an oven at 270 ° C. for 5
A foam was obtained by free foaming for a minute. Using the obtained foam, a laminated composite was obtained in the same manner as in Example 1.

The residual value (% by weight), apparent density (g / cm ³ ) and thickness (mm) of the resulting foam were measured, and the results are shown in Tables 3 and 4.

[0039]

[Table 3]

[0040]

[Table 4]

Furthermore, a slice in the thickness direction of the cells in the surface layer portion of the obtained foam was taken, and this slice was taken with a scanning electron microscope (Hitachi, model: S-2300) at a magnification of 50.
I took a picture with double and observed. In the photograph observation, the total number of all the bubbles in a certain area (1.89 mm ² ) at a predetermined position of the surface layer within 0.8 mm from the surface of the foam is counted, and the diameter (mm) in the thickness direction is measured. Then, the average value (a) was calculated, and the ratio (%) of the number of bubbles (n) within the range of the average value (a) ± 15% to the total number of bubbles (N) was calculated and obtained. The results are shown in Tables 3 and 4 above.

Next, using the obtained laminated composite, the appearance was observed and evaluated, and then the H / D value was measured to evaluate the strength and flexibility of the surface layer portion of the foam, and the peel strength was measured. The adhesiveness between the foam and the skin material was evaluated, and the obtained results are shown in Table 5.
It was shown to.

[0043]

[Table 5]

The above appearance was evaluated as ◯ when swelling, dents, surface roughness and the like were not visually observed, and was evaluated as x when even one spot was observed.

The above H / D value was obtained by heating the obtained laminated composite with a far-infrared heater and setting the temperature of the surface layer of the foam to 1
The temperature is raised to 50 to 160 ° C., vacuum molding is performed using a cylindrical female die having a diameter of 100 mm, and the depth H of the obtained molded product is H.
(Cm) and diameter D (cm) were measured, and the ratio H / D was calculated.

The peel strength was measured by using a test piece having a width of 25 mm and a length of 100 mm produced by cutting the obtained laminated composite, and using an autograph (manufactured by Shimadzu Corporation, model: DCS-5).
000) at 20 ° C or 120 ° C for 5 minutes and then peeled at the same temperature (kg / 25mm)
Was measured.

Example 6 Using a predetermined amount (part) of the composition shown in Table 6, an accelerating voltage of 5
A foam was obtained in the same manner as in Example 1 except that a predetermined amount (Mrad) of electron beam was irradiated at 00 kV, and the obtained foam was used to obtain a laminated composite in the same manner as in Example 1. In addition, the electron beam irradiation amount (Mrad) actually used, the furnace temperature (° C.) of the vertical hot air foaming furnace, the cross-linking sheet entry speed (m / m)
Second) and the winding speed (m / sec) of the foam are shown in Table 7.

[0048]

[Table 6]

[0049]

[Table 7]

Example 7 Using the foam obtained in the same manner as in Example 6, Example 2
A laminated composite was obtained in the same manner as in.

Example 8 Using the prescribed amount (part) of the composition shown in Table 6 above, the prescribed electron beam irradiation dose (Mrad), furnace temperature (° C.) and entry speed (m) shown in Table 7 above were used. / Sec) and a winding speed (m / sec) were used to obtain a foam in the same manner as in Example 6. Using the obtained foam, a laminated composite was obtained in the same manner as in Example 1.

Example 9 The crosslinked sheet obtained in the same manner as in Example 6 was placed in an oven and foamed for 5 minutes at a temperature of 250 ° C. while applying a load of 5 g / cm ² in the longitudinal direction to obtain a foamed product. It was Using the obtained foam, a laminated composite was obtained in the same manner as in Example 1.

Example 10 A foam was obtained in the same manner as in Example 9 except that foaming was performed while applying a load of 5 g / cm ^{2 in} the thickness direction. Using the obtained foam, a laminated composite was obtained in the same manner as in Example 1.

Comparative Examples 5 to 7 Predetermined electron beam irradiation dose (Mrad), furnace temperature (° C), penetration speed (m / sec) and winding speed (m /) shown in Table 7 above.
A foam was obtained in the same manner as in Example 6 except that the condition of (sec) was used. Using the obtained foam, a laminated composite was obtained in the same manner as in Example 1.

Comparative Example 8 A foam was obtained in the same manner as in Example 9 except that foaming was performed while applying a load of 40 g / cm ^{2 in} the thickness direction. Using the obtained foam, a laminated composite was obtained in the same manner as in Example 1.

The residual value (% by weight), apparent density (g / cm ³ ) and thickness (mm) of the obtained foam were measured, and the results are shown in Tables 8 and 9.

[0057]

[Table 8]

[0058]

[Table 9]

Further, a section in the thickness direction of the cells in the surface layer portion of the obtained foam and a section in the direction orthogonal to the thickness direction were respectively taken, and these sections were taken with a scanning electron microscope (manufactured by Hitachi Ltd., model: S- 2300) and photographed at a magnification of 60 times and observed. The photograph is 0.8 mm from the surface of the foam.
The thickness in the thickness direction and the diameters in the length and width directions orthogonal to the thickness direction are measured for all the bubbles in a certain area (1.89 mm ² ) at the predetermined position of the surface layer of Mean value of diameter in the depth direction (a), mean value of diameter in the length direction (b) and mean value of diameter in the width direction (c), and ratio of mean values (a) / (b) and (a) / Calculate (c),
The obtained results are shown in Tables 8 and 9 above.

Next, using the obtained laminated composite, the appearance, the strength and flexibility of the surface layer portion of the foam, and the adhesiveness between the foam and the skin material were evaluated in the same manner as in Example 1 to obtain the product. The results are shown in Table 10.

[0061]

[Table 10]

[0062]

The structure of the laminated composite of the present invention is as described above, and therefore the strength and flexibility of the surface layer portion of the foam are excellent, the foam and the skin material are well adhered, and A molded product free from swelling and wrinkles can be obtained.

Claims (2)

[Claims] 1. Apparent density 0.02-0.2 g / cm
^{3. A} laminated composite comprising a polyolefin resin foam having a xylene extraction residue value of 20 to 80% by weight at 120 ° C. and a skin material, wherein the foam is at least 0 from the surface on the side laminated with the skin material. The average value (a) of the diameters in the thickness direction of all the bubbles whose center is located in the surface layer portion within 0.8 mm is 0.05 to 1 mm, and the diameter in the thickness direction of the bubbles is the average value ( A laminated composite characterized in that the number of bubbles within the range of ± 15% of the value of a) is 80% or more. 2. Apparent density 0.02-0.2 g / cm
^{3. A} laminated composite comprising a polyolefin resin foam having a xylene extraction residue value of 20 to 80% by weight at 120 ° C. and a skin material, wherein the foam is at least 0 from the surface on the side laminated with the skin material. The average value (a) of the diameters in the thickness direction of all the bubbles whose center is located in the surface layer portion within 0.8 mm is 0.05 to 1 mm, and the average value (a) is orthogonal to the thickness direction. The average value (b) and the average value (c) of the diameters in the length direction and the width direction are expressed by the following formula (1).
And (2) are satisfied, The laminated composite characterized by the above-mentioned. 0.6 ≦ (a) / (b) ≦ 1.5 (1) 0.6 ≦ (a) / (c) ≦ 1.5 (2)