JPH0675939B2 - Foamable molding laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is a molding using a foamable sheet layer obtained by blending a propylene resin with a specific other olefin resin and a foaming agent and crosslinking the mixture. For a laminated body.

[Conventional technology]

Since propylene resin foams such as polypropylene are generally superior to polyethylene foams in physical properties such as heat resistance, strength, and rigidity, high-temperature insulation materials,
Coatings are expanding as packaging materials, building materials, lightweight structural materials, etc.

Polypropylene (hereinafter abbreviated as “PP”) has lower viscoelasticity when melted than polyethylene, particularly high-pressure low-density polyethylene, and the foamable material containing PP as a main component is
It is difficult to obtain a high-quality foam because the foaming gas easily moves through the material and escapes.

Therefore, it has been proposed to incorporate a cross-linking agent in the production of a PP foam to appropriately cross-link the material to increase the melt viscoelasticity so that the foaming gas does not escape from the material. (For example, Japanese Examined Patent Publication No. 46-31754) However, as described in this publication, PP alone has an insufficient foaming property and a high expansion ratio cannot be obtained, and moreover, the cells are coarse. Further, this publication describes that PP may be blended with other polymers such as polyethylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, and ethylene / propylene copolymer. , These polymers have a faster crosslinking reaction with a radical generator than PP, and when mixed with PP, the crosslinking of these polymers alone proceeds rapidly, so if the compounding ratio is small, the crosslinked polymer is Not only can the foamability of PP be improved by being dispersed in PP, but also the foamability is impaired due to the lack of affinity at the interface with PP.

Therefore, the present applicant has added a radical generator and a crosslinking aid to PP, and a propylene-based composition for a crosslinked foam containing a specific other olefin resin and a method for producing a foamable sheet using this composition. Invented and proposed. (Japanese Patent Application No. 60-24382, Japanese Patent Application No. 60-20941 and Japanese Patent Application No. 60-166
No. 36, Japanese Patent Application No. 60-10781) By using the expandable sheet produced according to these techniques, a polypropylene crosslinked foam having a high expansion ratio and uniform distribution of closed cells and good skin can be obtained.

[Problems to be Solved by the Present Invention]

The above-mentioned foamable sheet (a) itself has an appropriate rigidity, and also has a good lateral holding property and is efficiently subjected to secondary processing when heat-foaming or during secondary processing such as press molding. be able to.

Further, this foamable sheet (a) is heat-foamed and subjected to secondary molding such as press molding, and the foam molded into various shapes is excellent in lightweight and retains appropriate rigidity. Therefore, it is suitable as a core material for various interior materials.

On the other hand, in order to apply this foamable sheet (a) to a wider range of applications, as a result of studying compounding with other materials, a backing material (b) selected from inorganic fibrous materials such as glass wool and polyolefin resin It was found that the strength is improved by laminating and integrating with the foamable sheet (ii).

Structure of the Invention [Means for Solving the Problem] The molding laminate of the present invention has the following structure.

60 to 95 parts by weight of propylene-based resin (A) selected from crystalline homopolymers of propylene and copolymers of propylene with other α-olefin of 15 mol% or less and 1-butene content Α selected from 70 mol% or more of 1-butene polymer and a random copolymer of propylene with an propylene content of 55 to 85 mol% and an α-olefin selected from α-olefin copolymers having 4 to 20 carbon atoms. −
5 to 40 parts by weight of the olefin resin (B) Further, a blowing agent is added to 100 parts by weight of the (A) and (B).
A backing material (b) selected from an inorganic fibrous material and a polyolefin resin is integrally laminated on one surface of a foamable sheet (a) which is blended in a proportion of 0.5 to 5 parts by weight and cross-linked. A molding laminate having a foaming property.

Among the molding laminates of the present invention, the method for producing the foamable sheet (a) is preferably the following method. That is, 0.05 to 0.5 parts by weight of the radical generator (C) per 100 parts by weight of the propylene resin (A) and the α-olefin resin (B) in total, and further 100 parts by weight of the above (A) and (B) in total. (A) consisting of 0.1 to 1 part by weight of crosslinker (D),
A mixture containing four components (B), (C) and (D),
100 parts by weight of the crosslinked propylene-based resin composition obtained by melt-kneading at a temperature equal to or higher than the decomposition temperature of the radical generator (C) in the absence of a foaming agent that generates gas by heating to cause a crosslinking reaction. And 0.5 to 5 parts of a blowing agent that generates gas by heating are kneaded at a temperature lower than the decomposition temperature of the blowing agent to form a sheet.

As another preferable manufacturing method, in the above manufacturing method, a mixture of (A), (B), (C) and (D) and a foaming agent is foamed at a temperature not lower than the decomposition temperature of the radical generator (C) and foamed. There is a method of kneading at a temperature at which the agent does not decompose to form a sheet.

[Structure of foamable sheet (a)]

The raw material propylene resin (A) used in the present invention is
Melt flow rate (MFR: ASTM D 1238L) is 0.1 to 50 g / 10 min, preferably 0.5 to 20 g / 10 min, other than propylene homopolymer propylene and 15 mol% or less ethylene, 1-butene, It is a crystalline polymer selected from copolymers with other α-olefins such as 4-methyl-1-pentene, 1-hexene, 1-octene and 1-decene. If the MFR is less than 0.1 g / 10 min, it is difficult to knead and extrude during the cross-linking process, which is not industrial, while if it exceeds 50 g / 10 min, the amount of the cross-linking auxiliary agent required for improving the foamability is large. Too much, not practical.

The α-olefin resin (B) which is another raw material used in the present invention is a 1-butene polymer having a 1-butene content of 70 mol% or more and a propylene content of 55 to 85 mol% and propylene and 4 carbon atoms. To 20 random copolymers with α-olefins.

The 1-butene polymer having a 1-butene content of 70 mol% or more,
Melt flow rate (MFR: ASTM D 1238, L) is 0.05 to 50 g / 10 min, preferably 0.1 to 20 g / 10 min, 1-butene content is 70 mol% or more, preferably 75 mol% or more, and for thermal analysis of DSC. A homopolymer of 1-butene or a random copolymer of 1-butene and an α-olefin having 2 to 20 carbon atoms, which has a heat of fusion of crystals of 20 Joule / g or more, preferably 30 Joule / g or more, and preferably has a melting point. 70 ℃
Above, more preferably above 80 ° C.

Propylene resin (A) with MFR less than 0.05g / 10min
It is difficult to disperse it uniformly in the resin, while those exceeding 50 g / 10 min are practical because the amount of cross-linking agent required to improve the foamability by mixing with the propylene resin (A) and co-crosslinking is too high. Not. If the 1-butene content is less than 70 mol% and the heat of crystal fusion is less than 20 Joule / g, the difference in melting point from the propylene resin (A) is too large, and uniform dispersibility due to heating and kneading is insufficient. However, the radical generator (C) and the cross-linking agent (D), which are added at the time of cross-linking this, have a strong tendency to be localized in the portion of the 1-butene polymer, and the co-cross-linking efficiency with the propylene resin is high. It is lowered and the bubbles become coarse, and the foamability is not improved.

In the 1-butene polymer, the α-olefin copolymerized with 1-butene is an α-olefin having 2 to 20 carbon atoms, and specifically, for example, ethylene, propylene,
4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-tetradecene, 1-octadecene and the like can be mentioned.

The measurement of the heat of fusion of the 1-butene polymer in the present invention is a value calculated on the basis of the heat of fusion of indium using the area of the endothermic part based on the crystal melting of the copolymer by the differential scanning calorimeter. is there.

The heat of fusion and the melting point are measured under the following measurement conditions. That is, the sample is left at 200 ° C. for 5 minutes, cooled to −35 ° C. at a rate of 10 ° C./min, and left at −35 ° C. for 1 minute. afterwards
Measure from -35 ° C to 200 ° C at a heating rate of 10 ° C / min.

70-mol% 1-butene content having the above properties
The above 1-butene polymer is, for example, (a) a composite containing at least magnesium, titanium and halogen,
Random copolymerization of 1-butene and α-olefin or 1-butene using a catalyst formed from (b) an organometallic compound of a Group 1 to 3 metal of the periodic table and (c) an electron donor. Obtained by homopolymerizing butene. Part or all of the electron donor (c) may be fixed to part or all of the composite (a), and may be pre-contacted with the organometallic compound (b) before use. Good. Particularly preferred is a mode in which a part of the electron donor (c) is fixed to the composite (a), and the rest is added to the polymerization system as it is or is used in pre-contact with the organometallic compound (b). is there. In this case, the electron donor fixed to the composite (a) may be the same as or different from the electron donor used as it is in addition to the polymerization system or used in pre-contact with (b). May be.

The above-mentioned random copolymer of propylene and α-olefin has a melt flow rate (MFR: ASTM D 1238, L).
0.05 to 20g / 10min, preferably 0.1 to 10g / 10mi
n, propylene content 55 to 85 mol%, preferably 6
A random copolymer of propylene having a crystal melting amount of 0 to 80 mol% and a DSC thermal analysis of 25 to 70 Joule / g, preferably 30 to 60 Joule / g, and an α-olefin having 4 to 20 carbon atoms, Preferably having a melting point of 80 to 130
C., more preferably 90 to 120.degree.

Propylene resin (A) with MFR less than 0.05g / 10min
It is difficult to uniformly disperse the resin. On the other hand, if it exceeds 20 g / 10 min, it is not practical because the amount of the crosslinking aid required for improving the foaming property by mixing with the propylene resin (A) and co-crosslinking is too large. . Any of those having a propylene content of more than 85 mol% or a heat of crystal fusion of more than 70 Joule / g do not improve the fineness of the foamable cells and the uniformity of the cell diameter even when mixed with the propylene resin (A).

On the other hand, when the propylene content is less than 55 mol% and the heat of crystal fusion is less than 25 Joule / g, the difference in melting point from the propylene resin (A) is too large, and uniform dispersibility due to heat kneading is insufficient. Further, the radical generator (C) and the cross-linking agent (D), which are added to cross-link this, have a strong tendency to be localized in the random copolymer portion, and the co-crosslinking efficiency of the propylene-based resin (A) decreases. As a result, the bubbles become coarse and the foamability is not improved.

In addition to the above characteristics, the propylene / α-olefin random copolymer has a microisotacticity (hereinafter abbreviated as MIT) of 0.7 or more, and 0.8 or more, and boiling n-heptane in terms of three propylene chains. The insoluble content is preferably 5% by weight or less, more preferably 3% by weight or less. When MIT less than 0.7 is used, the chemical resistance of the foam, particularly the durability to organic solvents, is impaired, and
The heat resistance and rigidity are reduced and the characteristics of PP foam are impaired.

In the random copolymer, the α-olefin having 4 to 20 carbon atoms to be copolymerized with propylene is, for example, 1-butene, 4-methyl-1-pentene, 1
-Hexene, 1-octene, 1-decene, 1-tetradecene, 1-octadecene and the like.

The measurement of the heat of fusion of the random copolymer is a value calculated based on the heat of fusion of indium using the area of the endothermic part based on the crystal melting of the copolymer by a differential scanning calorimeter.

The heat of fusion and the melting point are measured under the following measurement conditions. That is, the sample is left at 200 ° C. for 5 minutes, cooled to −35 ° C. at a rate of 10 ° C./min, and left at −35 ° C. for 1 minute. afterwards
Measure from -35 ° C to 200 ° C at a heating rate of 10 ° C / min.

Microisotacticity refers to the part of three propylene chains by the ¹³ C nuclear magnetic resonance spectrum.
It is a value obtained by quantifying the fraction of individual propylene arranged isotactically.

The boiling n-heptane insoluble matter is quantified by the following method. That is, a strip sample of about 1 mm x 1 mm x 1 mm and glass beads are put into a cylindrical glass filter (G3) and extracted with a Soxhlet extractor for 14 hours. In this case, the frequency of reflux is about 15 minutes each time. Insoluble matter weight%
Is determined by weighing the melted portion or insoluble matter.

Propylene content having the above properties 55 to 55
The 85 mol% propylene / α-olefin copolymer is, for example, (a) a complex containing at least magnesium, titanium and halogen (b) a group 1 to 3 group of the periodic table.
It is obtained by random copolymerization of propylene and α-olefin using a catalyst formed from an organometallic compound of a group metal and (c) an electron donor. Part or all of the electron donor (c) may be fixed to part or all of the composite (a), and may be pre-contacted with the organometallic compound (b) before use. Good. Particularly preferred is a mode in which a part of the electron donor (c) is fixed to the composite (a), and the rest is added to the polymerization system as it is or is used in pre-contact with the organometallic compound (b). is there. In this case, the electron donor fixed to the composite (a) may be the same as or different from the electron donor used as it is in addition to the polymerization system or used in pre-contact with (b). May be.

As the radical generator (C) used in the method of the present invention, organic peroxides and organic peroxide esters are mainly used, and the decomposition temperature for obtaining a half-life of 1 minute (min) is the melting point of the α-olefin resin (B). Is higher than the melting point of the propylene-based resin (A). The radical generator (C)
The decomposition temperature is 40 ℃ to obtain the half-life of 100 hours (hr).
The above is practically preferable.

Specific examples of these organic peroxides include, for example,
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), meta -Toluoyl peroxide (8), benzoyl peroxide (9), tertiary butyl peroxyisobutyrate (10), 1,1-bis (tertiary butyl peroxy) 3,3,5-trimethylcyclohexane (11), 1, 1-bis (tert-butylperoxy) cyclohexane (12), tert-butylperoxymaleic acid (13), tert-butylperoxylaurate (14), tert-butylperoxy 3,5,
5-trimethylhexanoate (15), cyclohexanone peroxide (16), tert-butyl peroxyisopropyl carbonate (17), 2,5-dimethyl-2,5
-Di (benzoylperoxy) hexane (18), tert-butylperoxyacetate (19), 2,2-bis (tert-butylperoxy) butane (20), tert-butylperoxybenzoate (21), n-butyl-4 , 4-Bis (tert-butylperoxy) valerate (22), di-tert-butyldiperoxyisophthalate (23), methyl ethyl ketone peroxide (24), α, α'-bis (tert-butylperoxyisopropyl) benzene (25 ), Dicumyl peroxide (26), 2,5-dimethyl-2,5-di (tertiary peroxy) hexane (27), tertiary butyl cumyl peroxide (28), diisopropylbenzene hydroperoxide (29), di-tertiary Li-butyl peroxide (30), para-menthane hydroperoxide Oxide (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) and tertiary butyl hydroperoxide (36) are mentioned. Of these, (12) ~ (3
6) is preferred.

Further, the cross-linking agent (D) is an unsaturated compound having one or more double bonds, an oxime compound, a nitroso compound, a maleimide compound, or the like, and the α-olefin random system by the radical generator (C). The polymer radical is stabilized by reacting with the crosslinking agent (D) faster than the polymer radical cleavage reaction caused by the hydrogen abstraction of the resin (B) and the propylene-based resin (A), and at the same time, the α- Mutual cross-linking of the olefin resin (B) and the propylene resin (A),
And, each of them has a function of increasing the crosslinking efficiency.

Specific examples of these compounds include triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, diallyl phthalate, pentaerythritol triacrylate, neopentyl glycol diacrylate, 1,6-hexane. Diol dimethacrylate,
Examples include polyfunctional monomers such as divinylbenzene, oxime compounds such as quinonedioxim, benzoquinonedioxim, paranitrosophenol, N, N-meta-phenylenebismaleimide, and mixtures of two or more thereof. To be Of these, neopentyl glycol diacrylate, 1,6-hexanediol dimethacrylate, divinylbenzene, and mixtures thereof are preferred.

If the amount of the cross-linking agent (D) is less than 0.1 parts by weight, the progress of the cross-linking reaction of the propylene-based resin (A) and the α-olefin-based resin (B) by the radical generator will be insufficient, so that the melt viscoelasticity Is not sufficiently improved, if it exceeds 1 part by weight, it is difficult to mix the foaming agent and then extrude it into a sheet, and the appearance of the foam is not good.

The foaming agent used in the method of the present invention is a chemical substance that is liquid or solid at room temperature and decomposes by heating to generate a gas, and is not particularly limited as long as it has a decomposition temperature not lower than the melting point of the propylene resin (A). Not done. Such foaming agents include azodicarbonamide, barium azodicarboxylate,
N, N'-dinitrosopentamethylenetetramine, 4,4-oxybis (benzenesulfonylhydrazide), diphenylsulfone-3,3-disulfonylhydrazide, p-toluenesulfonylsemicarbazide, trihydrazinotriazine, biurea, zinc carbonate, etc. Is mentioned. Among these, azodicarbonamide, which has a large amount of gas generation and whose gas generation end temperature is sufficiently lower than the thermal deterioration start temperature of the propylene resin (A) / α-olefin resin (B) mixed system,
N, N'-dinitrosopentamethylenetetramine and trihydrazinotriazine are preferred.

In the present invention, the amount of the propylene resin (A) used is
60 to 95 parts by weight, preferably 70 to 90 parts by weight, based on 100 parts by weight of the total of (A) and (B),
The amount of the olefin resin (B) used is likewise 40 to 5 parts by weight, preferably 30 to 10 parts by weight. If the amount of the α-olefin resin (B) is less than 5 parts by weight, the dispersibility of the radical generator (C) and the cross-linking agent (D) is poor, and the radical generator (C) of the propylene resin (A) is used. Suppression of decomposition becomes insufficient, and it becomes difficult to obtain a good molded product. On the other hand, α-olefin resin (B)
If the amount exceeds 40 parts by weight, the heat resistance, strength and rigidity of the molded product will be impaired.

Furthermore, in the present invention, the amount of the radical generator (C) is 100 parts by weight based on 100 parts by weight of the above (A) and (B).
The amount is 0.05 to 0.5 part by weight, preferably 0.1 to 0.3 part by weight. The amount of cross-linking agent (D) is 0.1 to 1 part by weight, preferably 0.2 to 0.5 part by weight. The amount of the foaming agent is 0.5 to 5 with respect to 100 parts by weight of the crosslinked propylene resin composition.
Parts by weight, preferably 1 to 3 parts by weight. If the amount of the radical generator (C) deviates from the above range and is too small,
An appropriate increase in the melt viscoelasticity of the mixed system (A) and (B) cannot be achieved, and the foaming gas is likely to be dispersed out of the system, and it is difficult to obtain a foam-molded article having good closed cells. On the other hand, when the amount is out of the above range and is too much, cleavage is caused in the chain portion of the polymer of (A) and / or (B), and the melt viscoelasticity of the mixed system of (A) and (B) is increased. As a result, a foamed molded product having good closed cells cannot be obtained. If the amount of the cross-linking agent (D) deviates from the above range and becomes too small, the desired increase in melt viscoelasticity cannot be achieved, and the foaming gas has good closed cells accompanied by dissipation to the outside of the system. It is difficult to obtain a foam-molded product, and if the amount exceeds the above range and becomes excessive, the degree of crosslinking becomes excessive, making it difficult to mold the foamable sheet and / or the foam-molded product, or the skin of the molded product deteriorates. Practicality is lost.

In addition, when the amount of the radical generator (C) is used in an amount less than the equivalent required for crosslinking, the free crosslinking agent (D) remains, which may cause safety and hygiene problems such as odor and elution. It is a waste of resources and not practical.

If the amount of the foaming agent deviates from the above range and is too small, a foam having a foaming ratio of 2 times or more cannot be obtained. On the other hand, if the amount exceeds the above range, the expansive force of the generated gas becomes too large, resulting in a molten resin. Since the extensibility of the film becomes insufficient and the film begins to break, the gas escapes, the effective utilization rate of the gas decreases, the expansion ratio decreases, and the closed cell degree decreases.

Propylene resin (A), α-olefin resin (B)
When the radical generator (C) and the cross-linking agent (D) are kneaded together, a total of 100 weight parts of the propylene resin (A) and the α-olefin resin (B) of the phenolic heat stabilizer having 30 or more carbon atoms are mixed. Addition of 0.05 to 1 part by weight, preferably 0.1 to 0.5 part by weight, to control the generation concentration of polymer radicals to increase the crosslinking efficiency and heat the laminated sheet for foaming and thermal processing of the foam. It is preferable since it prevents oxidative deterioration of the product and enhances the heat aging resistance of the product in use.

Examples of such heat-resistant stabilizers include n-octadecyl-3- (4'-hydroxy-3 ', 5'-di-tert.
-Butylphenyl) propionate, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-tris (4-tert-butyl-3)
-Hydroxy-2,6-dimethylbenzyl) -S-triazine-2,4,6- (1H, 3H, 5H) trione, 1,3,5-trimethyl-2,4,6-tris (3,5- Di-tert-butyl-4-hydroxyphenyl) benzylbenzene, 1,3,5-tris (3,5-di-tert-butyl-4'-hydroxybenzyl) -S-triazine-2,4,6- ( 1H, 3H, 5H) trione, tetrakis [methylene-3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, and mixtures of two or more thereof.

When mixing the cross-linking composition and the foaming agent, a part of the propylene-based resin (A) is made into a powder, and the proportion is 15 to 50 parts by weight, preferably 15 to 30 parts by weight, based on 100 parts by weight of the cross-linking composition. If it is blended, the dispersibility of the foaming agent is improved, so even if the foaming agent is cohesive, the bubbles do not become huge.

In addition to this, if the foaming agent is mixed with an additive having a function of preventing secondary aggregation of the foaming agent in advance, the dispersibility of the foaming agent in the material is improved, and a good result without coarse bubbles is obtained. A laminated foam can be obtained. Such additives include
Metal soaps and surfactants are available. Specifically, a substance that is solid at the kneading temperature of the cross-linking agent and the foaming agent, such as stearic acid metal salt and stearyl monoglyceride, is preferable.

As a method of forming a sheet of a foamable material obtained by kneading a cross-linking composition and a foaming agent, a foaming agent is added and dispersed in a cross-linking composition heated and melted by a biaxial kneader such as Brabender, and then a calender roll is used. A sheet-forming method using a press molding machine, a method of kneading using an extruder, and then forming a sheet through a T-die or an annular die. 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 after kneading and molding is low in energy consumption and required time, and also flatness of a sheet and extruded skin are obtained. Good and preferable.

[Construction of Molding Laminate Having Foamability]

The foamable molding laminate of the present invention is formed by laminating and integrating a backing material (b) selected from an inorganic fibrous material and a polyolefin resin on one surface of the foamable sheet (a).

As the backing material (b), a non-woven sheet of inorganic fibrous material such as glass wool, a sheet of polyolefin resin,
Nonwoven fabrics such as polyethylene terephthalate are exemplified.

The non-woven fabric of the inorganic fibrous material usually has a basis weight of 10 g / m ² to 2000 g / m ² , preferably 50 g / m ² to 500 g / m ² .

Examples of the polyolefin resin sheet include a polypropylene sheet, a propylene-ethylene-block copolymer sheet, and a polyethylene sheet (preferably a high-density polyethylene sheet). If necessary, a synthetic rubber such as ethylene / propylene-diene rubber may be used. Fillers such as talc, paper, and wood powder are also included. The thickness of these polyolefin resin sheets is usually about 0.1 to 2 mm.

The method for laminating and integrating the backing material (b) with the foamable sheet (a) includes (i) melting the backing material (b) consisting of the foamable sheet (a) and the polyolefin resin sheet by co-extrusion. How to integrate in the state.

(Ii) A method in which the foamable sheet (a) is extruded and laminated on one side of the preformed backing material (b).

(Iii) A method in which a foamable sheet (a) and a backing material (b) which have been formed in advance are laminated and integrated by interposing an adhesive, a pressure-sensitive adhesive or the like.

Is exemplified.

Further, the molding laminate of the present invention includes a mode in which a backing material (b) is laminated and integrated on one surface of the foamable sheet (a), and various facing materials, pads and the like are laminated on the other surface. Examples of the skin material include thermoplastic elastomer, polyvinyl chloride leather, carpet, nonwoven fabric and the like. Examples of the pad material include a polyethylene foam sheet and a polyurethane foam sheet.

Representative specific examples of the molding laminate of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of an essential part showing an example of the molding laminate of the present invention. The thickness of the foamable sheet (a) is about 0.3 mm to 5
In the case of a polyolefin sheet, the thickness of the backing material (b) laminated and integrated on both sides thereof is about 0.1 mm to 2 mm, preferably about 0.3 to 1.0 mm. If the expandable sheet (a) is less than 0.3 mm, the rigidity is poor, and it is difficult to laterally carry the molding laminate during heating / foaming, pressing or vacuum forming. If it exceeds 5 mm, the merit of weight reduction will not be utilized. If the thickness of the backing material (b) of the polyolefin resin sheet is less than 0.1 mm, the internal pressure of the foam cells of the foamable sheet (a) cannot be resisted due to the thinning in deep drawing, and the backing material of the polyolefin resin sheet (B) Perforation may occur. Furthermore, sufficient reinforcing effect cannot be obtained. On the other hand, if it exceeds 2 mm, the advantage of weight reduction achieved by the molding laminate of the present invention cannot be obtained.

FIG. 2 is a sectional view of an essential part showing another example of the molding laminate of the present invention. Foamable sheet (a) and backing material (b)
Is similar to the case of FIG. 1, the backing material (b) is laminated and integrated only on one side of the foamable sheet (a), and the pad material 12 is provided on the other side of the foamable sheet. The skin material 13 is integrally laminated. The thickness of the pad material 12 is usually about 1
To 10 mm, preferably about 2 to 5 mm, and skin material 1
The thickness of 3 is usually about 0.05 to 1.0 mm. Preferably 0.
2 to 0.8 mm.

FIG. 3 is a sectional view of an essential part showing another example of the molding laminate of the present invention. Foamable sheet (a) and backing material (b)
2 is similar to the case of FIG. 2, but in this embodiment, the skin material 13 having both the function of the skin material and the function of the pad material is used.

The following are specific examples of the molding laminate as described above.

Backing material (b) / foaming sheet (a) Backing material (b) / foaming sheet (a) / PPE / TPE Backing material (b) / foaming sheet (a) / polyurethane foam / TPE backing material (b) / Foaming sheet (ii) / PPE / Polyvinyl chloride leather Lining material (ii) / Foaming sheet (ii) / Polyurethane foam / Polyvinyl chloride leather Lining material (ii) / Foaming sheet (ii) / Polyvinyl chloride Leather Lining material (b) / Foamable sheet (a) / Low-foaming polyethylene Here, TPE is a skin material made of thermoplastic elastomer, and is styrene-based, hydrogenated styrene-based, olefin-based, ester-based, urethane-based, ion Examples include various types such as cross-linking systems.

PPE is a soft foaming sheet made of polypropylene.

[Action]

The propylene-based resin, which is the main component of the foamable material used in the production of the molding laminate of the present invention, has a MFR in a specific range, and by combining it with a specific α-olefin-based resin, a component is obtained. It is possible to prevent the composition from being uniformly dispersed, the co-crosslinking of both to occur, the melt viscoelasticity of the material to be increased, and the foaming gas to be aggregated and the bubbles to become coarse. Therefore, while fine bubbles are uniformly distributed,
A molded product having a foamed layer with a high expansion ratio can be obtained. Since the cross-linking is performed prior to kneading the foaming agent with the foamable material, the selection range of the cross-linking agent, the cross-linking conditions, the foaming agent and the like is wide. These benefits are found in the invention already disclosed, and can be fully enjoyed in the present invention.

The following methods are available for heating and foaming the molding laminate of the present invention. That is, (1) a normal pressure foaming method in which a laminated sheet is placed on a heating plate and heated, (2) in addition to the above (1), use of radiant heat from a heating element, (3) heating by high frequency induction, 4) heating using an oven, and (5) hot air heating. In either method, the foamable sheet (a)
It is preferable to place the layer of the foamable sheet above the skin material in the molding laminate so that other materials can prevent the foamed layer from sagging even if is softened.

The molding laminate is molded while foaming is occurring or is nearly complete, but the sheet is still plastic. Processing methods include press molding, vacuum molding, and pressure molding. When performing heating and molding at the same time, put the laminated sheet in the press mold, close the mold to heat and mold, and when the decomposition of the foaming agent is completed, open the mold and expand the foaming gas to expand the laminated foam molded body. obtain.

Function of the backing material (b) When the molding laminate of the present invention is subjected to draw forming during or after heat foaming, the backing material (b) is laminated and integrated on the surface of the foamable sheet (a). Therefore, the range of use of the foamable sheet (a) is expanded and the strength is improved.

Applications to which the laminated molded article of the present invention is applied are suitable for various building materials, interior materials, especially automobile interior materials that can utilize lightweight properties, such as doors, ceilings, seat backs, pillars, rear parcels, and luggage compartments. Suitable for interior decoration.

Example 1. Polypropylene "B200" (MFR, Mitsui Petrochemical Industries, Ltd.)
= 0.5) pellets 55 parts by weight and powder 15 parts by weight,
0.2 parts by weight of dicumyl peroxide as a crosslinking agent, 0.5 parts by weight of divinylbenzene as a crosslinking aid, and tetrakis [methylene-3 (3,5-di-ter
t-Butyl-4-hydroxyphenyl) propionate] methane “Irganox 1010” (manufactured by ciba Geigy), n
-Octadecyl-3- (4'-hydroxy-3 ', 5'-
Di-tert-butylphenyl) propionate "I rganox
1076 "(same), calcium stearate 0.1 each
A composition for use in the present invention was prepared by adding 30 parts by weight of the following PBR as a modifying resin to a basic system consisting of parts by weight.

PBR: Propylene / 1-butene random copolymer, MFR: 7.
0g / 10min, propylene content 71.0mol%, heat of crystal fusion: 50Joule / g, boiling n-heptane insoluble matter: 0.5%, boiling methyl acetate soluble matter: 0.5%, MIT: 0.94 Machine (Henschel mixer)
Was mixed and finely pelletized together with crosslinking in an extruder.

To 100 parts by weight of each of these crosslinked fine pellets, 2 parts by weight of a mixture obtained by mixing 15 parts by weight of the polypropylene powder, 100 parts by weight of azodicarbonamide as a foaming agent, and 5 parts by weight of stearyl monoglyceride with a low speed mixer. In addition, they were mixed using a high speed mixer.

As shown in Fig. 4, the foamable material thus obtained was used in an extruder equipped with a fish tail type die having an opening width of 50 mm and an opening thickness of 1 mm. The resin temperature was 190 ° C and the screw rotation speed was 40 rpm. A sheet having a thickness of 1 mm was extruded under the above conditions. The sheet 11 immediately after the extrusion, the glass wool non-woven fabric 15 (100 g / m ^{2 of} basis weight), and the pad material 12 that have been formed in advance
(Polyethylene foam with a thickness of 2.5 mm) and skin material 13
The laminated product (a mirastomer having a thickness of 0.4 mm) was rolled with the pad material in the middle to be integrated into a molding laminate having a layer structure as shown in FIG. 2 and cut into a fixed length.

The molding laminate thus prepared is clamped at both ends with the foamable sheet 11 facing upward as shown in FIG.
Fix with B, and use heater 7 heated to about 200 ° C from above for about 5
Heated for minutes. The laminated sheet 1B having completed the foaming and having an increased embedded thickness was transferred to the mold 9 of the vacuum molding machine shown in FIG. 6 and molded. Remove from mold, cool, trim, 7th
A laminated foam molded article 1C shown in the figure was obtained.

When the foaming ratio of the foamed layer was calculated from the specific gravity by the water displacement method, it was 3.0 times.

Table 1 shows the results of the falling weight impact strength of the laminated foam molded article 1C.

Comparative Example 1. The drop weight impact strength of the foam without the backing material in Example 1 is shown in Table 1.

Example 2. Example 1 was repeated except that the PBR was changed to the following BPR.

BPR: 1-butene / propylene random copolymer MFR: 7.4
g / 10min, propylene content 75mol%, heat of crystal fusion: 36
Joule / g Example 3. In Example 1, the backing material was a 0.5 mm thick PP sheet (MFR:
0.5 block copolymer). Table 1 shows the drop impact strength at that time.

[Brief description of drawings]

1 to 3 are cross-sectional views of a main part of the molding laminate of the present invention. FIG. 4 is a conceptual diagram for explaining a step of producing the molding laminate of the present invention. 5 and 6 are cross-sectional views for explaining the method for producing a laminated foam-molded article of the present invention. FIG. 5 shows the foaming step of the laminated sheet, and FIG. 6 shows the molding step. FIG. 7 is a schematic cross-sectional view showing an example of a laminated foam-molded article produced from the molding laminate of the present invention. 1A, 1B …… Laminated sheet, 1C …… Laminated foam molded product 11 …… Foamable sheet, 12 …… Pad material 13,14 …… Surface material 3A, 3B, 3C …… Roll 4 …… Extruder, 5… … T-die 7 …… Heater, 9 …… Vacuum forming mold 8A, 8B …… Clamp 12 …… Pad material 13 …… Surface material 14 …… Surface material that doubles as a pad material

Claims (1)

[Claims] 1. A propylene-based resin (A) selected from crystalline homopolymers of propylene and copolymers of propylene with 15% by mole or less of other α-olefins, which are crystalline.
60 to 95 parts by weight and 1-butene polymer having a 1-butene content of 70 mol% or more and propylene with a propylene content of 55 to 85 mol%,
Α-olefin resin (B) 5 to 40 selected from random copolymers with α-olefin having 4 to 20 carbon atoms
Further, the foaming agent is added to 100 parts by weight of (A) and (B).
A backing material (b) selected from an inorganic fibrous material and a polyolefin resin is integrally laminated on one surface of a foamable sheet (a) which is blended in a proportion of 0.5 to 5 parts by weight and crosslinked. A molding laminate having a characteristic foamability.