JP2016196160A - Method for producing foamed resin sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a foamed resin sheet of a resin composition containing a polyolefin-based resin and a woody filler with good productivity.SOLUTION: A method for producing a foam molding containing a woody filler that is a method for producing a foamed resin sheet, uses a foamable resin composition 1 containing (α) 100 pts.mass of a polyethylene-based resin; (β) 5-50 pts.mass of a woody filler; (γ) 10-300 pts.mass of an inorganic filler; and (δ) 1-10 pts.mass of a foaming agent, and uses a calender roll rolling film forming device. The method includes: (1) a step of rolling the formable resin composition 1 and forming a sheet 2 by using a calender roll 4 which is set at a temperature exceeding a melting point of the component (α) to a temperature lower than a decomposition temperature; (2) a step of winding the sheet around a calender roll 5 which is set at a temperature higher than the decomposition temperature of the component (δ) by 25°C or higher; and (3) a step of winding the sheet around a calender roll 6 which is set at a decomposition temperature of the component (δ) to a temperature lower than a temperature higher than the decomposition temperature by 25°C.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for producing a foamed resin sheet.

Conventionally, a foam of a resin composition containing a polyolefin-based resin and a wood-based filler has been used as a cosmetic material because of its excellent heat insulation and light weight. However, in order to control foaming and obtain a molded product with high dimensional accuracy, the shape of the molded product is limited, and it has been difficult to obtain a foamed resin sheet with high productivity.

JP-A-10-237206 JP 2002-361805 A JP 2004-308227 A Japanese Patent Laying-Open No. 2005-307033

The subject of this invention is providing the manufacturing method which can obtain the foamed resin sheet of the resin composition containing polyolefin resin and a wood type filler with sufficient productivity.

As a result of intensive studies, the present inventor has found that the above-described problems can be achieved by a specific production method.

That is, the present invention is a method for producing a foamed resin sheet,
(Α) polyethylene resin 100 parts by mass;
(Β) 5-50 parts by mass of a wooden filler;
(Γ) inorganic filler 10 to 300 parts by mass; and (δ) foaming agent;
Wherein the amount of the component (δ) is
Using a foamable resin composition that is 1 to 10 parts by mass with respect to a total of 100 parts by mass of the component (α), the component (β), and the component (γ), and using a calendar roll rolling film forming apparatus. And
(1) A step of rolling the foamable resin composition into a sheet using a calender roll set at a temperature exceeding the melting point of the component (α) and a temperature lower than the decomposition temperature of the component (δ). ;
(2) A step of winding the sheet obtained in the step (1) around a calender roll set at a temperature 25 ° C. or more higher than the decomposition temperature of the component (δ);
(3) A step of winding the sheet treated in the step (2) around a calender roll set at a temperature not lower than the decomposition temperature of the component (δ) and lower than the decomposition temperature by 25 ° C .;
It is a method including.

The second invention is a foamed resin sheet produced by the method described in the first invention.

By the production method of the present invention, a foamed resin sheet of a resin composition containing a polyolefin resin and a wood filler can be obtained with high productivity. The foamed resin sheet obtained by the production method of the present invention can be suitably used for a decorative sheet, a decorative wallpaper, and the like.

The present invention is a method for producing a foamed resin sheet, wherein (α) polyethylene resin 100 parts by mass; (β) wood filler 5-50 parts by mass; (γ) inorganic filler 10-300 parts by mass; and (Δ) foaming agent, wherein the blending amount of the component (δ) is 1 to 100 parts by mass with respect to a total of 100 parts by mass of the component (α), the component (β), and the component (γ). A foamable resin composition that is 10 parts by mass is used.

(Α) Polyethylene resin :
The component (α) functions to ensure the sheet manufacturability while receiving the component (β), the component (γ), and the like.

Examples of the polyethylene resin include high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, ethylene and α-olefin (for example, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 2-methyl-1-propene, 2-methyl-1-butene, 3-methyl-1-butene, 2-ethyl-1-butene, 2,3-dimethyl- Random copolymers with 1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, etc.), ethylene-vinyl acetate copolymers, and ethylene-acrylic acid Ester copolymers; and modified polyethylene obtained by graft polymerization with one or more compounds selected from the group consisting of unsaturated carboxylic acids and derivatives thereof Emissions-based resin; and the like. As said component ((alpha)), these 1 type, or 2 or more types of mixtures can be used.

The melting point of the component (α) is not particularly limited, but may be preferably 110 ° C. or higher, more preferably 120 ° C. or higher, from the viewpoint of the feel and handleability as a foamed resin sheet. From the viewpoint of manufacturability of the foamed resin sheet, it may be preferably 135 ° C. or lower.

In the present specification, the melting point is a Diamond DSC differential scanning calorimeter manufactured by PerkinElmer Japan Co., Ltd., held at 190 ° C. for 5 minutes, cooled to −10 ° C. at 10 ° C./min, and 5 at −10 ° C. In the second melting curve (melting curve measured in the last temperature rising process) measured by a program that holds for 10 minutes and raises the temperature to 190 ° C. at 10 ° C./min, the peak top temperature of the peak that appears on the highest temperature side Say.

The melt mass flow rate of the component (α) (measured under conditions of 190 ° C. and 21.18 N according to JIS K 7210: 1999) is not particularly limited, but is preferably from the viewpoint of the productivity of the foamed resin sheet. It may be 0.1 to 20 g / 10 minutes, more preferably 0.3 to 10 g / 10 minutes.

In recent years, there is also a polyethylene resin produced using a monomer derived from a biomass raw material (hereinafter sometimes abbreviated as biomass polyethylene resin), which is commercially available. It is also one of the preferred embodiments that a biomass polyethylene resin is used as the component (α) so as to be a target of the biomass mark of the Japan Organic Resources Association or the biomass plastic mark of the Japan Bioplastics Association.

(Β) Wood-based filler :
The component (β) serves to increase the rigidity of the foamed resin sheet obtained by the production method of the present invention and the machinability during post-processing. It also works to improve design.

Examples of the wood filler include wood powder and cellulose. Examples of the wood powder include finely pulverized wood and saw dust generated when wood is cut. The cellulose is a polysaccharide in which D-glucose is β-1,4-glucoside-bonded, and is usually obtained from cotton, hemp, woody plant, and the like, and is sometimes referred to as pulp. As said component ((beta)), these 1 type, or 2 or more types of mixtures can be used.

When the foamed resin sheet obtained by the production method of the present invention requires whiteness, it is preferable to use high-purity chemical pulp as the component (β). When the foamed resin sheet obtained by the production method of the present invention does not need whiteness, from the viewpoint of cost, the above component (β) contains a large amount of wood flour and components other than cellulose (such as hemicellulose and lignin). It is preferable to use a pulp such as mechanical pulp.

From the viewpoint of the feel of the foamed resin sheet obtained by the production method of the present invention, the particle diameter of the component (β) is preferably larger. On the other hand, the smaller one is preferable from the viewpoint of manufacturability of the foamed resin sheet. Therefore, the particle size of 90% by mass or more is preferably 90% by mass or more and 40% by mass of 4000 mesh pass, and more preferably 90% by mass or more by 90 mesh% or more by 1000 mesh pass.

The blending amount of the component (β) is 5 parts by mass or more, preferably 10 parts by mass or more from the viewpoint of the feel with respect to 100 parts by mass of the component (α). On the other hand, it is 50 parts by mass or less, preferably 30 parts by mass or less from the viewpoint of manufacturability of the foamed resin sheet.

(Γ) Inorganic filler:
The component (γ) helps the dispersion of the component (β) in the production (melt kneading) step of the foamable resin composition used in the production method of the present invention, and is obtained by the production method of the present invention. It works to make it free from defects such as bumps.

Examples of the inorganic filler include zeolite, calcium carbonate, bentonite, talc, mica, clay, barium sulfate, natural silicic acid, synthetic silicic acid (white carbon), titanium oxide, and carbon black. It is preferable to use zeolite as the component (γ) because the foamed resin sheet obtained by the production method of the present invention can be provided with a humidity control function and a deodorizing function. As said component ((gamma)), these 1 type, or 2 or more types of mixtures can be used.

The average particle size of the component (γ) is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less, from the viewpoint of the productivity of the foamed resin sheet. On the other hand, it is preferably 0.01 μm or more, more preferably 0.02 μm or more from the viewpoint of helping the dispersion of the component (β) and preventing the occurrence of defects such as bumps.

In the present specification, the average particle size of the component (γ) is small in the particle size distribution curve measured using a laser diffraction / scattering particle size analyzer “MT3200II (trade name)” manufactured by Nikkiso Co., Ltd. The particle diameter is cumulative from 50% by mass.

The blending amount of the component (γ) is 10 parts by mass or more from the viewpoint of helping the dispersion of the component (β) and preventing the occurrence of defects such as blisters with respect to 100 parts by mass of the component (α). Is 20 parts by mass or more. On the other hand, from the viewpoint of manufacturability of the foamed resin sheet, it is 300 parts by mass or less, preferably 100 parts by mass or less.

(Δ) Foaming agent:
The component (δ) is decomposed and foamed in the step (2), and functions to make the sheet obtained in the step (1) into a foamed resin sheet.

Examples of the foaming agent include azo compounds such as azodicarbonamide; nitroso compounds such as N, N′-dinitrosopentamethylenetetramine; carbonates such as sodium bicarbonate and ammonium bicarbonate; citric acid, sodium citrate, And organic acids such as succinic acid; sodium borohydride; compounds such as p, p′-oxybisbenzenesulfonyl semicarbazide, p-toluenesulfonyl semicarbazide, trihydrazinotriazine, and barium azodicarboxylate; and thermal expansion microcapsules, etc. Can give. As said foaming agent, you may use combining the foaming agent mentioned above, such as the combination of carbonate and an organic acid, for example. As said component ((delta)), these 1 type, or 2 or more types of mixtures can be used.

The decomposition temperature of the component (δ) is preferably higher from the viewpoint of preventing decomposition and foaming from starting in the step (1). On the other hand, after the step (3), the lower the better, from the viewpoint of enabling the release from the calendar roll without any trouble. Therefore, although the decomposition temperature of the said component ((delta)) is based also on the resin characteristic of the said foamable resin composition, 145-180 degreeC is preferable normally and 150-170 degreeC is more preferable.

In this specification, the decomposition temperature of the foaming agent was measured by the following method. About the exothermic decomposition type foaming agent, using a melting point measuring device “M-560 (trade name)” of Nippon Büch Co., Ltd., packed in capillaries in a furnace preheated to a temperature lower by 10 ° C. or more than the decomposition temperature. The foaming agent was added, the temperature was raised at 5 ° C./min, and the temperature at which bubbles were generated in the tube in the capillary was visually measured. For the endothermic decomposition type foaming agent, use a gas behavior tracer (Gas Tracer (trade name)) from Eiwa Kasei Kogyo Co., Ltd., put the foaming agent in a test tube and immerse the whole test tube in an oil bath. The temperature is raised from 100 ° C. to 220 ° C. at a rate of 2 ° C./min, and the integral curve of the gas generation amount with respect to the temperature is measured. The point before the first bending point of the integral curve (before gas generation) is measured. The temperature at the intersection of the line drawn parallel to the horizontal axis passing through and the tangent drawn so that the gradient between the inflection points of the integral curve (during gas generation) was maximized was calculated.

The compounding amount of the component (δ) is based on 100 parts by mass of the total of the component (α), the component (β), and the component (γ) from the viewpoint of the productivity of the foamed resin sheet and the wood texture. 1 to 10 parts by mass, preferably 1.5 to 5 parts by mass.

The foamable resin composition includes a resin other than the component (α); a filler other than the component (β) and the component (γ) (for example, resin beads) as long as the object of the present invention is not adversely affected. Phenolic, phosphorus and sulfur antioxidants; anti-aging agents, light stabilizers and weathering agents such as UV absorbers; acid amides, fatty acids, fatty acid metal salts, waxes, silicone oils, and modified silicones Lubricants such as oil; Nucleating agents such as aromatic metal phosphates and gelols; Antistatic agents such as glycerin fatty acid esters; Various organic and inorganic flame retardants; Colorants; and copper damage inhibitors And various other optional components can be further included.

The production method of the present invention uses a calendar roll rolling film forming apparatus, (1) a calender roll set at a temperature exceeding the melting point of the component (α) and a temperature lower than the decomposition temperature of the component (δ). And a step of rolling the foamable resin composition into a sheet.

In the step (1), the foamable resin composition is rolled into a sheet. At that time, in order to prevent decomposition and foaming of the component (δ) from starting and stably perform the step (1), the temperature of the calender roll (roll surface temperature) in the step (1) It is set to a temperature lower than the decomposition temperature of δ), preferably 2 ° C. or more lower than the decomposition temperature of the component (δ), more preferably 5 ° C. lower than the decomposition temperature of the component (δ). In the step (1), from the viewpoint of preventing decomposition and foaming of the component (δ) from starting, the temperature of the calendar roll is preferably as low as possible. On the other hand, from the viewpoint of sufficiently plasticizing the component (α) and improving the surface state of the resulting sheet, the temperature of the calender roll exceeds the melting point of the component (α), preferably the component (α). The temperature is set to 5 ° C. or more higher than the melting point of the above, more preferably 10 ° C. higher than the melting point of the component (α).

Prior to the step (1), the foamable resin composition has a temperature exceeding the melting point of the component (α), preferably a temperature higher by 5 ° C. than the melting point of the component (α), more preferably the component. A temperature higher than the melting point of (α) by 10 ° C. or more and a temperature lower than the decomposition temperature of the component (δ), preferably 2 ° C. or more lower than the decomposition temperature of the component (δ), more preferably the component ( Preheating is preferably performed at a temperature 5 ° C. or more lower than the decomposition temperature of δ). Sheeting in the step (1) is facilitated.

The preheating method is not particularly limited, and can be performed by any method. For example, planetary multi-screw extruder, co-directional twin-screw extruder, different-direction twin-screw extruder, single-screw extruder, etc .; batch kneaders such as pressure kneaders and mixers; two-roll mixing, etc. By using a roll and a combination thereof, the foamable resin composition is melt-kneaded, and the preheated foamable resin composition is in the form of strands, sheets, rods, scraps, small blocks, etc. The method to obtain in the state of can be mentioned.

The production method of the present invention includes (2) a step of winding the sheet obtained in the step (1) around a calender roll set at a temperature 25 ° C. higher than the decomposition temperature of the component (δ). .

The sheet obtained in the step (1) is wound around a calender roll set at a temperature 25 ° C. or more higher than the decomposition temperature of the component (δ) in the step (2). The component (δ) is decomposed and foamed to form a foamed resin sheet.

Further, by foaming while being wound around the calender roll, the foam cell becomes a spindle / conduit shape elongated in the machine direction. Therefore, the foamed resin sheet obtained by the production method of the present invention can be suitably used as a decorative sheet for imparting a woody design.

The temperature of the calender roll (roll surface temperature) in the step (2) is 25% higher than the decomposition temperature of the component (δ) so that the component (δ) decomposes and foams rapidly and completely. It is set to a temperature higher by at least ° C, preferably at a temperature higher by at least 30 ° C than the decomposition temperature of the component (δ). On the other hand, from the viewpoint of preventing deterioration of the components (α) to (γ), the temperature of the calender roll is preferably 220 ° C. or lower, more preferably 200 ° C. or lower.

In the production method of the present invention, (3) the sheet treated in the step (2) is placed on a calender roll set to a temperature not lower than the decomposition temperature of the component (δ) and lower than 25 ° C. above the decomposition temperature. A step of winding.

In the step (3), the foamed sheet in the step (2) is cooled to a temperature not lower than the decomposition temperature of the component (δ) and lower than 25 ° C. higher than the decomposition temperature. It can be released from the calendar roll and sent to the next process without causing troubles such as adhesion to the guide roll. In addition, since it is maintained at a temperature equal to or higher than the decomposition temperature of the component (δ), the component (δ) remaining without being decomposed and foamed in the step (2) is decomposed and foamed so as not to remain. Can be.

The temperature of the calender roll (roll surface temperature) in the step (3) is such that the component (δ) is completely decomposed and foamed in the step (3) so as not to remain. It is set to a temperature equal to or higher than the decomposition temperature, preferably higher than the decomposition temperature of the component (δ) by 10 ° C. or higher, more preferably 15 ° C. higher than the decomposition temperature of the component (δ). On the other hand, the temperature of the calendar roll is less than 25 ° C. higher than the decomposition temperature of the component (δ), preferably from the viewpoint of allowing the sheet to be sent to the next step without causing trouble, The temperature is set to 20 ° C. or lower than the decomposition temperature of component (δ). It is more preferable that the temperature of the calendar roll in the step (3) is 180 ° C. or lower because release properties from the calendar roll become very good.

As the calender roll rolling film forming apparatus, the number of calender rolls used in the step (1) is 2 or more in order to form a rolled sheet, and the number of calender rolls used in the step (2) is one or more. There is no particular limitation except that the number of calender rolls used in the step (3) is one or more, and any apparatus can be used. For example, 2 rolls, upright type 3 rolls, upright type 4 rolls, L type 4 rolls, reverse L type 4 rolls, Z type roll, L type 6 rolls, reverse L type 6 rolls, and these The combination of can be given.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.

Measurement method (a) Foaming ratio:
From the volume and mass of the foamed resin sheet, the specific gravity (g1) of the foamed sheet was determined. Next, a resin composition not containing a foaming agent (in the case of Example 1, 100 parts by mass of (α-1), 20 parts by mass of (β-1), 40 parts by mass of (γ-1), and (γ -2) Resin composition containing 10 parts by mass and the above (ε-1) 10 parts by mass.) The resin sheet obtained in the same manner as the foamed resin sheet, except for the volume and mass. The specific gravity (g2) was determined. The expansion ratio (h) was calculated by the following formula.
h = g2 / g1

(B) Heat transfer speed:
Using a finger robot contact cold / warm sensation measuring device “KES-F7 (trade name)” manufactured by Kato Tech Co., Ltd., the heat transfer rate Qmax of the foamed resin sheet (temperature change rate ° C. / A value obtained by multiplying the maximum value of seconds by 0.1) was measured.

Raw material used (α) Polyethylene resin:
(Α-1) Biomass polyethylene resin “SGE7252 (trade name)” manufactured by Braschem, density 953 Kg / m ³ , MFR 2.2 g / 10 min, melting point 130 ° C.
(Α-2) Biomass polyethylene-based resin “SLL918 (trade name)” from Braschem, density 918 Kg / m ³ , MFR 2.7 g / 10 min, melting point 124 ° C.

(Β) Wood-based filler:
(Β-1) Wood flour, particle size 300 mesh pass 90% by mass or more, average particle size 60 μm.
(Β-2) Nippon Paper Industries Co., Ltd. high-purity chemical pulp “KC Flock W-400G (trade name)”, particle size 400 mesh pass 90 mass% or more, average particle size 24 μm.

(Γ) Inorganic filler:
(Γ-1) Zielite Co., Ltd. zeolite “SGW (trade name)”, average particle size 10 μm.
(Γ-2) Titanium dioxide “R-11P (trade name)” by Sakai Chemical Industry Co., Ltd., average particle size 0.20 μm.
(Γ-3) Calcium carbonate “Vigot 10 (trade name)” by Shiroishi Kogyo Co., Ltd., average particle size 0.1 μm.

(Δ) Foaming agent:
(Δ-1) Sodium hydrogen carbonate-based composite foaming agent “Selbon SC-53 (trade name)” manufactured by Eiwa Chemical Industry Co., Ltd., decomposition temperature 150 ° C. Endothermic decomposition type.
(Δ-2) An azodicarbonamide-based composite foaming agent “VINYHOLE DW # 6 (trade name)” from Eiwa Kasei Kogyo Co., Ltd., decomposition temperature 165 ° C. Exothermic decomposition type.

(Ε) Optional component:
(Ε-1) Zinc stearate.

Example 1
(Α-1) 100 parts by mass, (β-1) 20 parts by mass, (γ-1) 40 parts by mass, (γ-2) 10 parts by mass, (δ-1) 5 parts by mass ( (2.9 parts by mass) with respect to a total of 100 parts by mass of (α-1), (β-1), (γ-1), and (γ-2), and (ε-1 ) Using a mixer, the foamable resin composition containing 10 parts by mass was melt-kneaded under the condition of a resin temperature of 140 ° C during discharge, and then melted using a two-roll type mixing roll set at a temperature of 145 ° C. Immediately after kneading, it was put into an L-type four-roll type calender roll rolling film forming apparatus. The first two calendar rolls of the apparatus are preset to a temperature of 145 ° C. Using the first two calender rolls, the foamable resin composition is rolled, sent to a calender roll set at a temperature of 185 ° C. in advance, wound around this and foamed, and further heated in advance. It sent to the calender roll set to 165 degreeC, made to wind around this, and the sheet | seat was wound up after that and the 300-micrometer-thick foamed resin sheet was obtained. The above tests (A) and (B) were performed. The results are shown in Table 1.

Examples 2-15, Examples 1C-6C
Except that at least any one of the production conditions of the foamed resin sheet and the composition of the foamed resin composition was changed as shown in any one of Tables 1 to 3, the same procedure was performed as in Example 1. The results are shown in any one of Tables 1-3.

By the production method of the present invention, a foamed resin sheet of a resin composition containing a polyolefin resin and a wood filler could be obtained with high productivity. Moreover, since the obtained foamed resin sheet has a high foaming ratio and a low heat transfer rate, it can be used to obtain a decorative sheet, a decorative wallpaper, or the like having a high wood texture. On the other hand, in Examples 1C and 3C to 6C, the foamed resin sheet obtained had a low expansion ratio and a high heat transfer rate. In Example 2C, a rolled sheet could not be formed in step (1). Therefore, step (2) and subsequent steps could not be performed.

It is a conceptual diagram which shows an example of the manufacturing method of this invention.

1: Foamable resin composition 2: Sheet before foaming 3: Foamed resin sheet 4: First two calender rolls used in step (1) 5: Calender roll used in step (2) 6: Step (3 ) Calendar roll used in

Claims (2)

A method for producing a foamed resin sheet, comprising:
(Α) polyethylene resin 100 parts by mass;
(Β) 5-50 parts by mass of a wooden filler;
(Γ) inorganic filler 10 to 300 parts by mass; and (δ) foaming agent;
Wherein the amount of the component (δ) is
Using a foamable resin composition that is 1 to 10 parts by mass with respect to 100 parts by mass in total of the component (α), the component (β), and the component (γ),
Using a calendar roll rolling film forming device,
(1) A step of rolling the foamable resin composition into a sheet using a calender roll set at a temperature exceeding the melting point of the component (α) and a temperature lower than the decomposition temperature of the component (δ). ;
(2) A step of winding the sheet obtained in the step (1) around a calender roll set at a temperature 25 ° C. or more higher than the decomposition temperature of the component (δ);
(3) A step of winding the sheet treated in the step (2) around a calender roll set at a temperature not lower than the decomposition temperature of the component (δ) and lower than the decomposition temperature by 25 ° C .;
Including methods.
A foamed resin sheet produced by the method according to claim 1.