JPH0737710B2 - Multilayer stack - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a multilayer laminate used for a vehicle floor carpet or the like that is foamed and shaped in one step, and more specifically, has excellent cushioning property, sound absorbing property and heat insulating property. At the same time, it relates to a single-stage molded multilayer laminate having excellent sound insulation performance.

TECHNICAL BACKGROUND AND PROBLEMS OF THE INVENTION Floor carpets are often laid on the floors of vehicles such as automobiles, and such floor carpets for vehicles are usually provided on the back surface of a nonwoven fabric made of polyester, nylon, or the like. It has a structure provided with a backing material.

As a backing material for a multilayer laminate such as a vehicle floor carpet as described above, polyethylene with a filler has been mainly used in the past, but a polyethylene backing material with a filler perfectly fits various shapes such as a vehicle floor. Since it cannot be formed into such a shape, the felt is often used by being attached to a backing material. Therefore, there is a problem that the manufacturing process becomes complicated. Further, the polyethylene backing material containing a filler has a problem that it is inferior in sound absorbing performance and also in heat insulating performance.

On the other hand, multilayer laminates such as floor carpets for vehicles that use urethane foam as a backing material are also used for high-end vehicles, but urethane foam is expensive and its sound insulation performance is not very good. was there.

OBJECT OF THE INVENTION The present invention is intended to solve the problems associated with the above conventional techniques, and can be further foamed and shaped into a shape that fits the shape of a vehicle floor, Therefore, it is not necessary to stick felt, and it is used as a floor carpet for vehicles that has excellent cushioning properties without sticking felt, and also has excellent sound absorption and heat insulation properties as well as excellent sound insulation performance. The purpose is to provide a multilayer laminate.

SUMMARY OF THE INVENTION A multilayer laminate according to the present invention comprises a carpet surface material, a polyethylene layer containing a filler, and a foamed polyethylene layer as a backing material, and a foamed polyethylene sheet is foamed to form a foamed polyethylene layer as a backing material. When this is done, the drawing process is also performed at the same time so that the foaming and shaping are performed in one step.

The multilayer laminate according to the present invention comprises a carpet surface material, a polyethylene layer containing a filler, and a foamed polyethylene layer as a backing material, and when forming a foamed polyethylene layer as a backing material by foaming a foamable polyethylene sheet. Since it is foamed and shaped in one step by performing drawing at the same time, it can be molded in one step to fit the shape of the vehicle floor, etc. Therefore, it is not necessary to attach felt and the felt It has excellent cushioning properties, heat insulation properties, and sound absorption properties without being attached, and also has excellent sound insulation properties and is inexpensive.

Detailed Description of the Invention A multilayer laminate used as a vehicle floor carpet or the like according to the present invention will be specifically described below.

The multilayer laminate 1 according to the present invention has a carpet surface material 2, a filler-containing polyethylene layer 3, and a foamed polyethylene layer 4 as a backing material, as shown in the sectional view of FIG.
It consists of

The foamed polyethylene layer 4 as the backing material is formed by foaming the expandable polyethylene sheet by heating. When forming the foamed polyethylene layer 4 by foaming the expandable polyethylene sheet, drawing is also performed at the same time. Therefore, the multilayer laminate according to the present invention is one-step molded into a shape that fits various shapes.

As the carpet surface material 2, a carpet made of a nonwoven fabric such as polyester, nylon, acryl, polypropylene is usually used, but the carpet surface material 2 is not limited to these nonwoven fabrics, and can be widely used as long as it is a conventional carpet surface material. You can

The polyethylene in the filled polyethylene layer 3 is not foamed and has a melt flow rate (MFR 190 ° C)
Is 0.5 to 50 g / 10 min, for example high-pressure process low density polyethylene (MFR = 7.2 g / 10 min, density 0.91
7g / cm ³ ), linear low density polyethylene (MFR = 2.1g / 10
Min, density 0.920 g / cm ³ ) or the like can be used. In some cases, the ethylene content is 70 to 95 mol%,
Polyethylene resins ranging from soft to hard can also be used, such as ethylene-vinyl acetate copolymer containing 30% by weight or less of vinyl acetate, and ethylene containing a small amount of propylene, butene-1 or non-conjugated diene.
Propylene copolymer, ethylene-butene-1 copolymer,
It is also possible to use an ethylene / propylene / non-conjugated diene copolymer or the like.

Specific examples of the filler mixed with such polyethylene include talc and calcium carbonate (d = 2.7 g / c
c), barium sulfate or the like (d = 4.2 g / cc) can be used. This filler is preferably incorporated in polyethylene in an amount of 30 to 80% by weight.

Next, the expanded polyethylene layer 4 as a backing material will be described. The expanded polyethylene layer 4 is formed by heating and foaming an expandable polyethylene sheet.

Such a foamable polyethylene sheet comprises (A) polyethylene, (B) a crosslinking agent and / or a crosslinking auxiliary agent,
A foamable polyethylene sheet-forming composition containing (C) a foaming agent, (D) an organic peroxide and the like is formed into a sheet at a temperature at which the (C) foaming agent and (D) the organic peroxide are not decomposed. It is obtained by molding.

(A) For polyethylene, the melt flow rate (MF
Low density polyethylene whose R 190 ℃) is 0.5 to 50 g / 10 minutes,
For example, high pressure low density polyethylene (MFR = 7.2g / 10min,
Density 0.917g / cm ³ ), linear low density polyethylene (MFR =
2.1 g / 10 minutes, density 0.920 g / cm ³ ) etc. can be used, ethylene content is 70 to 95 mol% in some cases, and polyethylene resin ranging from soft to hard can be used, for example, 30 wt% The following ethylene-vinyl acetate copolymer containing vinyl acetate, etc., and ethylene containing a small amount of propylene, butene-1 or non-conjugated diene.
Propylene copolymer, ethylene-butene-1 copolymer,
It is also possible to use an ethylene / propylene / non-conjugated diene copolymer or the like. It is also possible to include an inorganic filler such as talc, calcium carbonate or barium sulfate in a layer of up to 50% by weight in this polyethylene.

The above-mentioned (B) cross-linking agent and / or cross-linking aid for cross-linking polyethylene (A) are not necessarily used, but are preferably used, and have one or more double bonds. An unsaturated compound, an oxime compound, a nitroso compound, a maleimide compound or the like is used. The (B) cross-linking agent and / or the cross-linking auxiliary is a polymer radical generated by the hydrogen abstraction of the (A) polyethylene by the (D) organic peroxide,
By reacting with the crosslinking aid (B) faster than causing a cleavage reaction, it stabilizes the polymer radicals and at the same time functions to increase the crosslinking efficiency.

As the (B) crosslinking agent and / or the crosslinking auxiliary agent,
Specifically, triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate,
Trimethylolpropane trimethacrylate, diallyl phthalate, pentaerythritol triacrylate,
Oxime compounds such as neopentyl glycol diacrylate, 1,6-hexanediol dimethacrylate, quinone dioxime, benzoquinone dioxime, paranitrosophenol, N, N-meta-phenylene bismaleimide, or a mixture of two or more of these Can be mentioned.
Of these, neopentyl glycol diacrylate, 1,6-hexanediol dimethacrylate, or a mixture thereof is preferable.

The (B) crosslinking agent and / or the crosslinking aid is preferably present in an amount of 0.1 to 1 part by weight based on 100 parts by weight of the (A) polyethylene.

The foaming agent (C) used in the composition for forming an expandable sheet is a chemical substance that is a liquid or a solid at room temperature and decomposes by heating to generate a gas, which is decomposed above the melting point of the polyethylene (A). There is no particular limitation as long as it has a temperature.

Examples of the foaming agent (C) include azodicarbonamide, barium azodicarboxylate, N, N'-dinitrosopentamethylenetetramine, 4,4-oxybis (benzenesulfonylhydrazide), diphenylsulfone-3,3-
Examples thereof include disulfonyl hydrazide, p-toluenesulfonyl semicarbazide, trihydrazino triazine, biurea and zinc carbonate. Among these, azodicarbonamide, N, which generate a large amount of gas and whose gas generation end temperature is sufficiently lower than the thermal deterioration start temperature of (A) polyethylene.
N'-dinitrosopentamethylenetetramine and trihydrazinotriazine are particularly preferred.

The (C) foaming agent is preferably present in an amount of 5 to 20 parts by weight based on 100 parts by weight of the (A) polyethylene.

As the organic peroxide (D) used for crosslinking the composition for forming a foamable sheet, organic peroxides and organic peroxyesters are mainly used.
The decomposition temperature for obtaining the half-life of 1 minute (min) of the organic peroxide is preferably higher than the melting point of (A) polyethylene.

As such (D) organic peroxide, specifically,
3,5,5-trimethylhexanoyl peroxide (1),
Octanoyl peroxide (2), decanoyl peroxide (3), lauroyl peroxide (4), succinic acid peroxide (5), acetyl peroxide (6), tertiary butyl peroxy (2-ethylhexanoate) (7), Turtle oil peroxide (8), benzoyl peroxide (9), tert-butyl peroxyisobutyrate (10), 1,1-bis (tert-butyl peroxy) 3,5,5-trimethylcyclohexane (11), 1,1 -Bis (tert-butyl peroxy) cyclohexane (12), tert-butyl peroxymaleic acid (13), tert-butyl peroxylaurylate (14), tert-butyl peroxy 3,5,
5-trimethylcyclohexanoate (15), cyclohexanone peroxide (16), tertiary butyl peroxyisopropyl carbonate (17), 2,5-dimethyl-2,5-di (benzoylperoxy) hexane (1
8), tertiary butyl peroxyacetate (1
9), 2,2-bis (tert-butylperoxy) butane (20), tert-butylperoxybenzoate (21), n-butyl-4,4-bis (tert-butylperoxy) valerate (22), ditertiary Butyl peroxyisophthalate (23), methyl ethyl ketone peroxide (24), α, α'-bis (tert-butyl peroxyisopropyl) benzene (25), dicumyl peroxide (26), 2,5-dimethyl-2,5-di (Tertiary butyl peroxy) hexane (27), tertiary butyl cumyl peroxide (28), diisopropylbenzene hydroperoxide (29), di-tertiary butyl peroxide (30), paramenthane hydroperoxide (31), 2,5 -Dimethyl-2,5-di (tert-butylperoxy) hexyne-3 32), 1,1,3,3
Tetramethylbutyl hydroperoxide (33), 2,5-
Dimethylhexane 2,5-dihydroperoxide (34),
Cumene hydroperoxide (35), tertiary butyl hydroperoxide (36) and the like can be mentioned. Of these, the compounds (12) to (36) are particularly preferable.

This (C) radical generator is the above-mentioned (A) polyethylene.
It is preferably present in an amount of 0.1 to 2.0 parts by weight per 100 parts by weight.

The composition for forming a foamable sheet according to the present invention may contain various additives in addition to the above-mentioned components.
For example, when kneading the above components, it is preferable to add a phenolic heat stabilizer having 30 or more carbon atoms.

The expansion ratio of the polyethylene layer is 10 to 40 times, preferably 15 to 30 times, and the thickness is 10 to 20 mm.
It is desirable that it is a degree. Also, the specific gravity of this expanded polyethylene layer differs greatly between the pressed part and the fully expanded part,
It is preferably about 0.9 to 0.04 g / cm ³ .

Next, a method for producing a multi-layer laminate using the composition for forming an expandable polyethylene sheet as described above will be described.

In order to form the foamable polyethylene sheet-forming composition into a sheet, the foamable polyethylene sheet-forming composition containing the above components is kneaded with a Brabender or the like, and then formed into a sheet with a calendar roll. A method, a method of forming into a sheet by a press molding machine, a method of kneading using an extruder, and a method of forming into a sheet through a T die or an annular die can be adopted. Among these, the last method, that is, the method of extruding from a T-die at a temperature lower than the decomposition temperature of the foaming agent (C) after kneading, is low in energy consumption and required time, and flatness of the sheet. Also, extruded skin is good and preferable.

When the foamable polyethylene sheet-forming composition is formed into a sheet, it is necessary to carry out at a temperature at which the foaming agent (C) does not decompose as described above. Specifically, azodicarbonamide was used as the foaming agent. In case 110-160 ℃ preferably
It is preferable that the composition for forming an expandable polyethylene sheet is formed into a sheet at about 120 to 140 ° C.

The thickness of this unfoamed expandable polyethylene sheet is
It is preferably about 0.5 to 5 mm.

When the unfoamed expandable polyethylene sheet 5 is molded from the expandable polyethylene sheet forming composition in this manner, it is preferable to coextrude the filler-containing polyethylene layer 3 at the same time. As shown in FIGS. 2 (a) to (c), on the filler-containing polyethylene foam layer 3 of the laminate of the filler-containing polyethylene layer 3 thus obtained and the unfoamed expandable polyethylene sheet 5, The carpet surface material 2 is integrated as a heat-sealing laminate to obtain a multilayer laminate precursor 6 having the carpet surface material 2, the polyethylene layer 3 containing a filler, and the expandable polyethylene sheet 5 as a backing material.

Next, this multilayer laminate precursor 6 is supplied to a vacuum forming machine,
The expandable polyethylene sheet side of the precursor 6 is heated and foamed by a ceramic heater or the like provided in this vacuum forming machine. The heating temperature at this time needs to be equal to or higher than the decomposition temperature of the foaming agent (C), and specifically, when azocarbonamide is used as the foaming agent, it is preferably heated to 200 ° C. or higher.

Simultaneously with the foaming of the expandable polyethylene sheet of the multilayer laminate precursor 6 by heating, the obtained vehicle floor carpet is drawn by a press molding machine or the like to be formed into a shape that fits the floor shape of the vehicle. At this time, since the foamed polyethylene sheet 4 is in a molten state, the pressing pressure may be extremely small, specifically, 1 to 50 kg / cm ²
It is a degree. It is preferable that the press die is not heated during the press working but is kept in a cooled state to cool the foamed polyethylene sheet 4 formed by foaming.

In the above-described method for producing a multilayer laminate, the carpet surface material 2 is heat-sealed and laminated on one surface of the filler-containing polyethylene layer 3 before the unfoamed expandable polyethylene sheet 5 is foamed by heating. , Fig. 3 (a)
As shown in (c), the laminate of the polyethylene layer 3 containing a filler and the expandable polyethylene sheet 5 in an unfoamed state is heated to foam, and at the same time, the carpet surface material 2 is laminated on the surface of the polyethylene layer 3 containing a filler. A multilayer laminate may be manufactured by integrating the laminates and molding the obtained laminate at the same time into a predetermined shape by a press laminating machine. According to this method, since it is not necessary to heat the carpet surface material 2 itself, the carpet surface material does not fall over.

The multilayer laminate according to the present invention comprises a carpet surface material, a polyethylene layer containing a filler, and a foamed polyethylene layer as a backing material, and a foamed polyethylene sheet is foamed to form a foamed polyethylene layer as a backing material. Since it is also formed in one step by performing drawing at the same time, it can be formed in one step into a shape that fits various shapes such as the vehicle floor, and therefore there is no need to attach a cushion material and the cushion Cushioning insulation, excellent sound absorption performance without attaching material,
Moreover, it has excellent sound insulation and is inexpensive.

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1 Polyethylene resin Density 0.917 g / cm ³ 100 parts by weight MFR 7.2 g / 10 min Crosslinking aid (triallyl isocyanurate) 0.5 parts by weight Blowing agent (azodicarbonamide) 10 Part by weight Organic peroxide (dicumyl peroxide): 0.5 part by weight of the composition for forming an expandable polyethylene sheet was well mixed in a Henshur mixer, and granulated by an extruder having a diameter of 65 mm to form pellets. Resin temperature at this time is 130 ℃
Met.

The pellets thus obtained are fed to a sheet molding machine (65 mm extruder, die width 550 mm, lip opening 2.0 mm), and at the same time, polyethylene containing a filler (polyethylene resin:
Density 0.917g / cm ³ , MFR 7.2g / 10min, filler: 60% by weight of calcium carbonate) is supplied to a sheet forming machine, and is laminated by force lamination and a polyethylene layer containing a filler and a sheet-like expandable polyethylene sheet. To produce a laminate. The extrusion temperature of the foamed PE layer was 120 to 140 ° C, the extrusion temperature of the PE layer containing the filler was 160 ° C, and the temperature of the coextrusion die was 140 ° C. No foaming of the expandable polyethylene sheet was observed during molding. The thickness of the expandable polyethylene sheet in the obtained laminate is 0.5 to 5 mm, and the thickness of the polyethylene layer with a filler is 0.5 to 2.0 mm,
At the time of sheet formation, a carpet surface material was heat-sealed and laminated on a polyethylene layer containing a filler to obtain a multilayer laminate precursor having an expandable polyethylene sheet as a backing.

The expandable polyethylene sheet side of the obtained multilayer laminate precursor was heated by a ceramic heater of a vacuum forming machine for about 2 minutes to foam the expandable polyethylene sheet to form a foamed polyethylene layer. At this time, the set temperature of the ceramic heater was 400 ° C. The obtained floor carpet for a vehicle was press-formed at the same time as foaming with a press die that was vertically aligned to have a predetermined shape. The press die during press molding was not heated and was kept at room temperature.

The density of the polyethylene foam layer of the obtained multilayer laminate was 0.04.
It was g / cm ³ and the gel fraction was 30% by weight.

Example 2 In Example 1, instead of the polyethylene resin for forming the expanded polyethylene, an ethylene / vinyl acetate copolymer (vinyl acetate content 14% by weight, MFR ... 3.5 g / 10 minutes,
A floor carpet for vehicles was manufactured in the same manner as in Example 1 except that the density was 0.93 g / cm ³ ).

Example 3 In Example 1, except that a linear low-density polyethylene (MFR: 2.1 g / 10 minutes, density: 0.920 g / cm ³ ) was used instead of the polyethylene resin for forming the foamed polyethylene. In the same manner as in Example 1, a floor carpet for vehicles was manufactured.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a multi-layer laminate according to the present invention.
FIGS. (A) to (c) and FIGS. 3 (a) to (c) are process explanatory views when manufacturing the multilayer laminate according to the present invention. 1 ... Multilayer laminate 2 ... Carpet surface material 3 ... Filler-containing polyethylene layer 4 ... Foamed polyethylene layer 5 ... Foamable polyethylene sheet 6 ... Multilayer laminate precursor

Claims (1)

[Claims] 1. A carpet surface material, a polyethylene layer containing a filler, and a foamed polyethylene layer as a backing material, which is subjected to a drawing process when the foamed polyethylene sheet is foamed to form the foamed polyethylene layer as a backing material. A multi-layer laminate characterized by being foamed and shaped in a single step by carrying out at the same time.