JP2005060689A - Foam and its producing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foam which is excellent in lightweight and heat resistance, and can be used for various applications, and its producing method. <P>SOLUTION: The foam comprises a resin composition in which a resin derived from a plant resource and a natural organic filler are compounded, and has an expansion magnification of 1.02-15 times. The foam is made from another resin composition comprising furthermore compounding a carboxy group-reactive terminal blocking agent therewith. The producing method of the foam comprises melt-kneading the resin derived from the plant resources, the natural organic filler and a foaming agent and producing the foam having the expansion magnification of 1.02-15 times. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a foam excellent in light weight and heat resistance, and further excellent in nail retention and wood screw retention, and a method for producing the same.

  The problem of depletion of fossil fuels such as petroleum has been highlighted, and biopolymers made of resin derived from plant resources have attracted attention as plastic materials.

  Among these, polylactic acid is expected to be a biopolymer capable of being melt-molded because lactic acid, which is a monomer, is produced at low cost by a fermentation method using microorganisms and has a high melting point of about 170 ° C.

  However, since polylactic acid resin alone has insufficient heat resistance and mechanical strength, studies have been made to add a filler in order to improve the problem. As the filler used, many attempts have been made to add naturally-derived organic fillers such as wood powder, paper powder and kenaf from the viewpoint of protecting the global environment.

However, when they are used as products such as molded products, they are extremely weak and vulnerable to impacts, so attempts have been made to make foams for the purpose of improving the problem and reducing the weight. Is also disclosed in Patent Document 1.
Patent Document 1 proposes a foam made of polylactic acid and plant powder and a method for producing the same, but the specifically obtained foam has a large foaming ratio and is reduced in weight. However, the heat resistance was insufficient.
JP 2001-302835 A (page 2-5)

  An object of this invention is to provide the foam excellent in lightness and heat resistance, and also nail retention property and wood screw retention property.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems.

That is, the present invention
(1) A foam comprising a resin composition obtained by blending a plant resource-derived resin and a naturally-derived organic filler, the foam having a foaming ratio of 1.02 to 15 times,
(2) The foam according to (1), wherein the plant resource-derived resin contains a polylactic acid resin, and the polylactic acid resin has a weight average molecular weight of 100,000 or more,
(3) The foam according to (1), wherein the plant resource-derived resin is a polylactic acid resin, and the temperature-lowering crystallization temperature (Tc) derived from the polylactic acid resin is 100 ° C. or higher.
(4) The foam according to (1), wherein the resin composition further comprises a carboxyl group-reactive endblocker.
(5) The foam according to (1), wherein the naturally-derived organic filler contains paper powder, and the paper powder contains aluminum, silicon, calcium, and sulfur,
(6) A method for producing a foam, characterized in that a foam having a foaming ratio of 1.02 to 15 times is obtained by melting and kneading a resin derived from plant resources, a natural organic filler and a foaming agent,
(7) The foam according to (6), wherein a foaming agent master batch obtained by melting and kneading a resin derived from plant resources and a foaming agent at a temperature lower than the decomposition temperature of the foaming agent is used as the foaming agent. It is a manufacturing method.

  ADVANTAGE OF THE INVENTION According to this invention, it is excellent in lightweight property and heat resistance, and also is excellent in nail retention property and wood screw retention property, and the foam which can be used for various uses, and its manufacturing method are provided.

  The (A) plant resource-derived resin used in the present invention is melt-moldable, and part or all of the monomer units forming the resin are made from plant resources such as corn, sweet potato, sugar cane, and wood. If it is, it will not be restrict | limited in particular. The resin derived from plant resources may be made from plant resources directly from glucose by microorganisms, such as polyhydroxybutyrate (for example, it is obtained using glucose from plant resources using microorganisms). Polyhydroxybutyrate, etc.), and once the monomer is made, it may be made by polymerizing the monomer (for example, lactic acid is obtained from glucose by microorganisms and polymerized. And polylactic acid obtained by the following method). Specific examples of monomer units obtained from these plant resources include lactic acid units, glycolic acid units, hydroxycarboxylic acid units such as hydroxybutanoic acid units, diol units such as butanediol, dicarboxylic acid units such as succinic acid, and glucose units. Is mentioned. When the monomer unit has optically active carbon, the optical purity of the monomer unit is usually high. Specific examples of plant resource-derived resins include polyhydroxyalkanoate resins such as polylactic acid resins, polyglycolic acid resins, and polyhydroxybutyrate resins, cellulose ester resins, polypropylene terephthalate resins, and polybutylene succinate resins. However, polylactic acid resin is particularly preferable from the viewpoint of heat resistance.

  The plant resource-derived resins may be used singly or in combination of two or more, but in the case of using two or more types in combination, a polylactic acid resin and other plant resource-derived resins may be used in combination. Preferably, 1 to 200 parts by weight of a resin derived from other plant resources is preferably used, more preferably 10 to 100 parts by weight, based on 100 parts by weight of the polylactic acid resin.

  The polylactic acid resin used in the present invention is a polymer mainly composed of L-lactic acid and / or D-lactic acid, but may contain other copolymerization components other than lactic acid. Other monomer units include ethylene glycol, propylene glycol, butanediol, heptanediol, hexanediol, octanediol, nonanediol, decanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, glycerin, pentane. Glycol compounds such as erythritol, bisphenol A, polyethylene glycol, polypropylene glycol and polytetramethylene glycol, oxalic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, malonic acid, glutaric acid, cyclohexanedicarboxylic acid, terephthalic acid , Isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, bis (p-carboxyphenyl) methane, anthracene dicarboxylic acid, 4,4′-diphenyl ether dicarbohydrate Acids, dicarboxylic acids such as 5-sodium sulfoisophthalic acid, 5-tetrabutylphosphonium isophthalic acid, hydroxycarboxylic acids such as glycolic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, hydroxybenzoic acid, and caprolactone And lactones such as valerolactone, propiolactone, undecalactone, and 1,5-oxepan-2-one. Such a copolymer component is preferably contained in an amount of generally 0 to 30 mol%, preferably 0 to 10 mol%, in all monomer components.

  In the present invention, it is preferable to use a polylactic acid resin having a high optical purity of the lactic acid component from the viewpoint of heat resistance. That is, among the total lactic acid components of the polylactic acid resin, it is preferable that 70% or more of the L isomer or 70% or more of the D isomer, and 80% or more of the L isomer or 80% or more of the D isomer. It is particularly preferred that 90% or more of the L isomer or 90% or more of the D isomer is contained, and 98% or more of the L isomer or 98% or more of the D isomer is contained. More preferably, the L-form is contained at 99% or more, or the D-form is contained at 99% or more. Moreover, the upper limit of the content of L-form or D-form is usually 100% or less.

  As a method for producing the polylactic acid resin, a known polymerization method can be used, and examples thereof include a direct polymerization method from lactic acid and a ring-opening polymerization method via lactide.

  The molecular weight and molecular weight distribution of the polylactic acid resin are not particularly limited as long as it can be substantially molded, but the weight average molecular weight is usually 10,000 or more, preferably 80,000 or more, more preferably Is preferably 100,000 or more, more preferably 130,000 or more. The upper limit is not particularly limited, but is preferably 500,000 or less, more preferably 300,000 or less, and more preferably 250,000 or less. The weight average molecular weight here refers to the molecular weight in terms of polymethyl methacrylate (PMMA) measured by gel permeation chromatography. When the weight average molecular weight is small, the wood screw holding force and the nail holding force tend to be reduced, and it becomes difficult to obtain a product of stable quality. On the other hand, when the weight average molecular weight is increased, the fluidity tends to decrease, and the molding process becomes difficult.

  The melting point of the polylactic acid resin is not particularly limited, but is preferably 120 ° C. or higher, more preferably 150 ° C. or higher, and particularly preferably 160 ° C. or higher. The melting point of the polylactic acid resin is usually increased by increasing the optical purity of the lactic acid component, and the polylactic acid resin having a melting point of 120 ° C. or higher contains 90% or more of the L form or 90% or more of the D form. In addition, a polylactic acid resin having a melting point of 150 ° C. or higher can be obtained by containing 95% or more of L-form or 95% or more of D-form.

  Any naturally-occurring organic filler used in the present invention can be used as long as it is derived from a natural product, but preferably contains cellulose.

  Specific examples of naturally-occurring organic fillers include paper powder, wood powder, bamboo powder, cellulose powder, rice husk powder, fruit shell powder, chitin powder, chitosan powder, protein and starch powder, rice husk, wood Chips such as chips, okara, waste paper crushed materials, clothing crushed materials, cotton fibers, hemp fibers, bamboo fibers, wood fibers, kenaf fibers, hemp fibers, jute fibers, banana fibers, coconut fibers, or other plant fibers or Examples include pulps and cellulose fibers processed from these plant fibers and fibrous fibers such as animal fibers such as silk, wool, Angola, cashmere, and camels. From the viewpoint of heat resistance, paper powder, wood powder, bamboo powder , Cellulose powder, rice husk powder, fruit husk powder, chitin powder, chitosan powder, protein powder, starch powder, cotton fiber, hemp fiber, bamboo fiber, wood fiber, kenaf fiber Plant fibers such as hemp fiber, jute fiber, banana fiber, coconut fiber are preferable, paper powder, wood powder, bamboo powder, cellulose powder, hemp fiber, bamboo fiber, kenaf fiber, hemp fiber, jute fiber are more preferable, paper Powder, wood powder, kenaf fiber, and hemp fiber are more preferable, and paper powder is particularly preferable. In addition, these naturally-derived organic fillers may be collected directly from natural products, but from the viewpoint of protecting the global environment and conserving resources, waste materials such as waste paper, waste wood and old clothes are recycled. May be used.

  Waste paper is newspaper, magazine, other recycled pulp, or paperboard such as corrugated cardboard, cardboard, paper tube, etc. Any one can be used as long as it is processed from plant fiber. From the viewpoint of safety, waste paper powder, which is a pulverized product of newsprint and cardboard such as cardboard, cardboard, and paper tube, is preferable.

  In addition, specific examples of wood used for wood flour include softwood materials such as pine, cedar, oak, and fir, and broad-leaved wood materials such as beech, shy, and eucalyptus.

  The size of the natural organic filler is preferably 10 mm or less, more preferably 5 mm or less, and even more preferably 1 mm or less from the viewpoint of heat resistance. Although a minimum in particular is not restrict | limited, From the point of handleability, 0.1 micrometer or more is preferable and 1 micrometer or more is more preferable. Moreover, about a fine powdery thing like 1 mm or less, what was compressed previously and made into the granular form of about 1-10 mm may be used.

  In the present invention, the water content of the naturally-derived organic filler is preferably 10% or less, preferably 5% or less from the viewpoint that the decomposition of the resin derived from plant resources can be suppressed and a stable color resin composition can be obtained. The following is more preferable, 3% or less is more preferable, and 1% or less is most preferable. The lower limit is not particularly limited, but it is preferably 0.1% or more in consideration of the danger such as dust explosion. Here, the moisture content is represented by [(air dry weight−absolute dry weight) / air dry weight] × 100 (%). The air dry weight is a weight in a state including moisture, and the absolutely dry weight is a weight dried at 100 ° C. or more until the weight becomes constant (constant weight).

  When the naturally-derived organic filler is paper powder, the paper powder is not particularly limited, but preferably contains an adhesive from the viewpoint of moldability. The adhesive is not particularly limited as long as it is usually used when processing paper. Emulsion adhesives such as vinyl acetate resin emulsions and acrylic resin emulsions, polyvinyl alcohol adhesives, Examples include cellulose-based adhesives, natural rubber-based adhesives, starch paste, and hot-melt adhesives such as ethylene-vinyl acetate copolymer resin-based adhesives and polyamide-based adhesives. Emulsion-based adhesives, polyvinyl alcohol-based adhesives An adhesive and a hot melt adhesive are preferable, and an emulsion adhesive and a polyvinyl alcohol adhesive are more preferable. These adhesives are also used as binders for paper processing agents. Adhesives include clay, bentonite, talc, kaolin, montmorillonite, mica, synthetic mica, zeolite, silica, graphite, carbon black, magnesium oxide, calcium oxide, titanium oxide, calcium sulfide, magnesium carbonate, calcium carbonate, carbonic acid. Inorganic fillers such as barium, barium sulfate, aluminum oxide and neodymium oxide are preferably contained, and clay, bentonite, talc, kaolinite, montmorillonite, synthetic mica and silica are more preferable.

  In addition, as a paper powder, a sizing agent such as rosin-based, alkyl ketene dimer-based, alkenyl succinic anhydride-based chemicals generally used as a raw material for papermaking from the viewpoint that the moldability can be improved. Paper strength enhancers such as polyacrylamide and starch, yield improvers such as polyethyleneimine, polymer flocculants, drainage improvers, deinking agents such as nonionic surfactants, slimes such as organic halogens Aluminum sulfate and polyaluminum used as fixing agents for control agents, organic or enzyme pitch control agents, hydrogen peroxide and other cleaning agents, antifoaming agents, pigment dispersants and lubricants, and sizing agents Chloride and other sodium hydroxide, magnesium hydroxide and sodium sulfate used as raw materials for papermaking Sodium silicate, aluminum chloride, preferably includes an inorganic material such as chlorine sodium.

  Moreover, as a paper powder, from a moldability viewpoint, it is preferable that an ash content is 5 weight% or more, It is more preferable that it is 5.5 weight% or more, It is further more preferable that it is 8 weight% or more. The upper limit is not particularly limited, but is preferably 60% by weight or less, and more preferably 30% by weight or less. Here, the ash content is the ratio of the weight of the remaining ash content when baking 10 g of the organic filler at a high temperature of 450 ° C. for 12 hours using an electric furnace or the like to the weight of the paper powder before baking.

  The paper powder preferably contains 5 to 20% by weight of an inorganic compound in the paper powder, more preferably contains aluminum, silicon, or calcium as an element of the inorganic compound, aluminum, silicon, calcium, Those containing sulfur are more preferred, those containing aluminum, silicon, calcium, sulfur and magnesium are particularly preferred, and those containing aluminum at least twice the content of magnesium are particularly preferred.

  The abundance ratio of aluminum, silicon, calcium, sulfur, and magnesium is not particularly limited. For example, when the total number of the elements is 100, aluminum is 1 to 60 mol% and silicon is 20 to 90. It is preferable that the mol%, calcium is 1 to 30 mol%, sulfur is 1 to 20 mol%, magnesium is 0 to 20 mol%, aluminum is 10 to 55 mol%, silicon is 20 to 85 mol%, and calcium is More preferably, it is 1 to 25 mol%, sulfur is 1 to 15 mol%, magnesium is 0 to 10 mol%, aluminum is 20 to 50 mol%, silicon is 25 to 80 mol%, and calcium is 3 to 20 mol%. %, Sulfur is 2 to 10 mol%, and magnesium is more preferably 0 to 8 mol%. About these elemental analysis, although it can measure even if it uses both the simple substance of a natural origin organic filler, and the ash content of a natural origin organic filler, in this invention, ash content is used. Elemental analysis is performed by using an apparatus that combines X-ray fluorescence analysis, atomic absorption spectrometry, scanning electron microscope (SEM) or transmission electron microscope (TEM), and energy dispersive X-ray microanalyzer (XMA). Although it can be measured, fluorescent X-ray analysis is used in the present invention.

  Moreover, as a paper powder, it is preferable from the viewpoint of a moldability to contain the cellulose which microparticles | fine-particles adhere on the surface. The fine particles are not particularly limited, and may be an inorganic filler contained in the adhesive as described above, and may be either an organic material or other inorganic material. The thing containing is preferable. The shape of the fine particles may be any of a needle shape, a plate shape, and a spherical shape. The size of the fine particles is not particularly limited, but is preferably distributed in the range of 0.1 to 5000 nm, more preferably in the range of 0.3 to 1000 nm. More preferably, it is distributed in the range of ˜500 nm, particularly preferably in the range of 1 to 100 nm, and most preferably in the range of 1 to 80 nm. Here, “distributed” in a specific range means that 80% or more of the total number of fine particles is included in the specific range. The adhesion form of the fine particles may be either in an aggregated state or a dispersed state, but is more preferably adhered in a dispersed state. The size of the fine particles is such that a molded product obtained from a resin composition containing a plant-derived resin and a naturally-derived organic filler can be observed with a transmission electron microscope at a magnification of 80,000 times. The total number is arbitrarily set to 100.

  Moreover, also in the organic filler derived from other natural products other than paper dust, it is preferable to select and use the above characteristics, that is, the ash content, the composition having the ash content, and the fine particles adhered.

  In the present invention, the blending amount of the naturally derived organic filler is not particularly limited, but from the viewpoint of moldability and heat resistance, when the polylactic acid resin is 100 parts by weight, 1 to 350 parts by weight It is preferably 5 to 200 parts by weight, more preferably 10 to 150 parts by weight, and particularly preferably 15 to 100 parts by weight. When the blending amount of the natural-derived organic filler is 1 part by weight or more, the effect of improving the moldability of the polylactic acid resin is sufficiently obtained, and when it is 350 parts by weight or less, the natural-derived organic filler is It is preferable in that it can be uniformly dispersed in a lactic acid resin, and in addition to moldability and heat resistance, a material excellent in strength and appearance as a material can be obtained.

  Moreover, in this invention, as long as the resin composition of this invention is obtained, the organic filler derived from a natural product can be used by 1 type, or 2 or more types, However, It should contain the paper powder which has the said preferable characteristic. preferable. Further, it is preferable to contain 50% by weight or more of waste paper powder.

  In the present invention, it is preferable to use a foaming agent in order to obtain a foam.

  Any foaming agent can be used as long as it can be used to obtain a foam. Chemical foaming agents, physical foaming agents, and the like can be used, and the foam of the present invention can be suitably obtained. A chemical foaming agent is preferable in terms of easy control of bubbles.

  Chemical foaming agents include azo compounds such as azodicarbonamide, azobisisobutyronitrile, barium azodicarboxylate, hydrazide compounds such as 4,4′-oxybisbenzenesulfonyl hydrazide and p-toluenesulfonyl hydrazide, dinitrosopenta Nitroso compounds such as methylenetetramine, hydrazo compounds such as hydrazodicarbonamide, 5-phenyltetrazole, 5-aminotetrazole, azobistetrazole, bistetrazole and other tetrazole compounds, hydrazodicarboxylic acid esters, azodicarboxylic acid esters, Examples thereof include ester compounds such as citric acid esters, isocyanate compounds, sodium bicarbonate, sodium carbonate, and the like, and azodicarbonamide and azobis Preferred are azo compounds such as butyronitrile and barium azodicarboxylate, tetrazole compounds such as 5-phenyltetrazole, 5-aminotetrazole, azobistetrazole, and bistetrazole, and isocyanate compounds, and azodicarbonamide and azobisisobutyridine. Azo compounds such as nitrile and barium azodicarboxylate are more preferred, and azodicarbonamide is more preferred.

  Physical foaming agents include ethane, butane, pentane, hexane, heptane, ethylene, propylene, petroleum ether, methyl chloride, monochlorotrifluoromethane, dichlorodifluoromethane, dichlorotetrafluoroethane, water, air, carbon dioxide, nitrogen gas Butane, pentane, hexane, water, air, carbon dioxide gas, nitrogen gas are preferred, water, air, carbon dioxide gas, nitrogen gas are more preferred, water, air, Carbon dioxide gas is more preferable. In addition, it is preferable to use a substance that can be used as a supercritical fluid such as carbon dioxide gas or nitrogen gas as a foaming agent in a supercritical fluid state because a foam that does not decrease in strength can be obtained.

  The addition amount of the foaming agent may be an effective amount for obtaining the expansion ratio defined in the present invention, and varies slightly depending on the type, but is 0.01 to 18 weights with respect to 100 parts by weight of the resin derived from plant resources. Parts, preferably 0.1 to 15 parts by weight, more preferably 0.5 to 10 parts by weight. If the amount is too small, the effect of the foaming agent is not sufficient, and if the amount is too large, the surface appearance may be impaired.

  In the present invention, in order to stabilize the foaming behavior and obtain a foam having good foaming ratio, foam density and cell size, as a foaming aid, metal oxides such as zinc oxide, calcium oxide and aluminum oxide, stearin Mixing aliphatic salts such as zinc acid, calcium stearate, magnesium stearate, aluminum stearate, calcium montanate, magnesium montanate, aluminum montanate, paraffin, alumina, talc, calcium carbonate, mica, silica, kaolin, etc. Is preferred.

  The addition amount of the foaming aid is preferably 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight, with respect to 100 parts by weight of the resin derived from plant resources. More preferably, it is ˜1 part by weight. If it is less than 0.01 parts by weight, the effect of the foaming aid is not sufficient, and if it exceeds 10 parts by weight, the surface appearance may be impaired, which is not preferable.

  In addition, as a foaming agent, it is a foam formed by melt-kneading a resin derived from a plant resource and a foaming agent at a temperature lower than the decomposition temperature of the foaming agent in that a product with stable quality can be obtained. It is preferable to use an agent masterbatch, and a suitable plant resource-derived resin, a preferred foaming agent, or such a foaming agent and a preferred foaming aid are appropriately selected, and are below the decomposition temperature of the foaming agent, preferably 50 to 200 ° C. More preferably, a foaming agent master batch obtained by melt-kneading in a temperature range of 100 to 180 ° C. is used. However, the lower limit of the above temperature range should be read as the lowest temperature at which melt kneading is possible when melt kneading is not possible due to the type of resin derived from plant resources to be used.

  In this invention, it is preferable to mix | blend a carboxyl group reactive terminal blocker further. The carboxyl group-reactive end-blocking agent used in the present invention is not particularly limited as long as it is a compound capable of blocking the carboxyl end group of the polymer, and is used as a blocker for the carboxyl end of the polymer. Things can be used. In the present invention, the carboxyl group-reactive endblocker not only blocks the end of a plant resource-derived resin, but also lactic acid produced by thermal decomposition or hydrolysis of a plant resource-derived resin or a natural-derived organic filler. The carboxyl group of acidic low molecular weight compounds such as formic acid can also be blocked. Further, the end-capping agent is more preferably a compound that can also block the hydroxyl end where an acidic low molecular weight compound is generated by thermal decomposition.

  Examples of such a carboxyl group-reactive end-blocking agent include glycidyl ether compounds, glycidyl ester compounds, glycidyl amine compounds, glycidyl imide compounds, alicyclic epoxy compounds, and other epoxy compounds, 2,2′-m-phenylenebis (2 -Oxazoline), oxazoline compounds such as 2,2'-p-phenylenebis (2-oxazoline), oxazine compounds, N, N'-di-2,6-diisopropylphenylcarbodiimide, 2,6,2 ', 6' -It is preferable to use at least one compound selected from carbodiimide compounds such as tetraisopropyldiphenylcarbodiimide and polycarbodiimide, and among them, epoxy compounds and / or carbodiimide compounds are preferable.

  As the carboxyl group-reactive end-blocking agent, one or more compounds can be arbitrarily selected and used.

In the foam of the present invention, the carboxyl terminal and the acidic low molecular weight compound may be appropriately blocked according to the use to be used, but the specific carboxyl terminal and acidic low molecular weight compound blocking degree may be included in the composition. The acid concentration is preferably 10 equivalents / 10 ⁶ g or less from the viewpoint of hydrolysis resistance, more preferably 5 equivalents / 10 ⁶ g or less, and particularly preferably 1 equivalents / 10 ⁶ g or less. . The acid concentration in the polymer composition can be measured by dissolving the polymer composition in a suitable solvent and then titrating with an alkali compound solution such as sodium hydroxide having a known concentration, or by NMR.

  The amount of the carboxyl group-reactive end-blocking agent is preferably 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight, when the plant resource-derived resin is 100 parts by weight.

  In the present invention, it is preferable to further add a reaction catalyst of a carboxyl group reactive end-blocking agent. The reaction catalyst referred to here is a compound that has an effect of promoting the reaction between the carboxyl group-reactive end-blocking agent and the carboxyl end of the polymer end or acidic low molecular weight compound. Certain compounds are preferred, for example, alkali metal compounds, alkaline earth metal compounds, and phosphate esters.

  The addition amount of the reaction catalyst is not particularly limited, but is preferably 0.001 to 1 part by weight and more preferably 0.01 to 0.2 part by weight with respect to 100 parts by weight of the plant resource-derived resin. More preferably, 0.02 to 0.1 parts by weight is most preferable.

  In the present invention, it is preferable to further add a crystallization accelerator in that the bubble size can be easily controlled. The crystallization accelerator used in the present invention can be selected from a wide variety of compounds, but the crystal nucleating agent that promotes the formation of crystal nuclei of the polymer, or the softening of the polymer to facilitate movement and promote crystal growth. A plasticizer can be preferably used.

  The blending amount of the crystallization accelerator used in the present invention is preferably 0.01 to 30 parts by weight and preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the plant resource-derived resin. More preferred is 1 to 10 parts by weight.

  The crystal nucleating agent used as the crystallization accelerator in the present invention is not particularly limited, and any of an inorganic crystal nucleating agent and an organic crystal nucleating agent can be used. Specific examples of inorganic crystal nucleating agents include talc, kaolin, montmorillonite, synthetic mica, clay, zeolite, silica, graphite, carbon black, zinc oxide, magnesium oxide, titanium oxide, calcium sulfide, boron nitride, calcium carbonate, sulfuric acid Examples thereof include metal salts of barium, aluminum oxide, neodymium oxide and phenylphosphonate. These inorganic crystal nucleating agents are preferably modified with an organic substance in order to enhance dispersibility in the composition.

  Specific examples of organic crystal nucleating agents include sodium benzoate, potassium benzoate, lithium benzoate, calcium benzoate, magnesium benzoate, barium benzoate, lithium terephthalate, sodium terephthalate, potassium terephthalate, Calcium oxide, sodium laurate, potassium laurate, sodium myristate, potassium myristate, calcium myristate, sodium octacosanoate, calcium octacosanoate, sodium stearate, potassium stearate, lithium stearate, calcium stearate, magnesium stearate, Barium stearate, sodium montanate, calcium montanate, sodium toluate, sodium salicylate, potassium salicylate, salicylic acid , Metal salts of organic carboxylic acids such as aluminum dibenzoate, potassium dibenzoate, lithium dibenzoate, sodium β-naphthalate, sodium cyclohexanecarboxylate, organic sulfonates such as sodium p-toluenesulfonate, sodium sulfoisophthalate, stearic acid Amide, ethylenebislauric acid amide, palmitic acid amide, hydroxystearic acid amide, erucic acid amide, carboxylic acid amides such as trimesic acid tris (t-butylamide), low density polyethylene, high density polyethylene, polypropylene, polyisopropylene, polybutene Polymers such as poly-4-methylpentene, poly-3-methylbutene-1, polyvinylcycloalkane, polyvinyltrialkylsilane, and high melting point polylactic acid, Sodium salt or potassium salt of a polymer having a carboxyl group such as sodium salt of ethylene-acrylic acid or methacrylic acid copolymer, sodium salt of styrene-maleic anhydride copolymer (so-called ionomer), benzylidene sorbitol and its derivatives, sodium-2, Phosphorus compound metal salts such as 2'-methylenebis (4,6-di-t-butylphenyl) phosphate and 2,2-methylbis (4,6-di-t-butylphenyl) sodium can be exemplified. .

  As the crystal nucleating agent used in the present invention, among those exemplified above, at least one selected from talc and an organic carboxylic acid metal salt is particularly preferable. The crystal nucleating agent used in the present invention may be used alone or in combination of two or more.

  The compounding amount of the crystal nucleating agent is preferably 0.01 to 30 parts by weight, more preferably 0.05 to 10 parts by weight with respect to 100 parts by weight of the resin derived from plant resources. .1 to 5 parts by weight is particularly preferable.

  The plasticizer used in the present invention is not particularly limited. For example, polyester plasticizer, glycerin plasticizer, polycarboxylic acid ester plasticizer, phosphate ester plasticizer, polyalkylene glycol Examples thereof include a plasticizer and an epoxy plasticizer.

  Specific examples of the polyester plasticizer include acid components such as adipic acid, sebacic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, propylene glycol, 1,3-butanediol, 1,4-butane. Examples thereof include polyesters composed of diol components such as diol, 1,6-hexanediol, ethylene glycol and diethylene glycol, and polyesters composed of hydroxycarboxylic acid such as polycaprolactone. These polyesters may be end-capped with a monofunctional carboxylic acid or monofunctional alcohol, or may be end-capped with an epoxy compound or the like.

  Specific examples of the glycerin plasticizer include glycerin monoacetomonolaurate, glycerin diacetomonolaurate, glycerin monoacetomonostearate, glycerin diacetomonooleate, and glycerin monoacetomonomontanate.

  Specific examples of polycarboxylic acid plasticizers include phthalates such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, diheptyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, and trimellitic acid. Trimellitic acid esters such as tributyl, trioctyl trimellitic acid and trihexyl trimellitic acid, adipic acid esters such as diisodecyl adipate and n-octyl-n-decyl adipate, citric acid such as triethyl acetylcitrate and tributyl acetylcitrate Examples include esters, azelaic acid esters such as di-2-ethylhexyl azelate, dibutyl sebacate, and sebacic acid esters such as di-2-ethylhexyl sebacate.

  Specific examples of the phosphate ester plasticizer include tributyl phosphate, tri-2-ethylhexyl phosphate, trioctyl phosphate, triphenyl phosphate, diphenyl-2-ethylhexyl phosphate and tricresyl phosphate. .

  Specific examples of the polyalkylene glycol plasticizer include polyethylene glycol, polypropylene glycol, poly (ethylene oxide / propylene oxide) block and / or random copolymer, polytetramethylene glycol, ethylene oxide addition polymer of bisphenols, bisphenols Polyalkylene glycols such as propylene oxide addition polymers, tetrahydrofuran addition polymers of bisphenols, or terminal-capped compounds such as terminal epoxy-modified compounds, terminal ester-modified compounds, and terminal ether-modified compounds.

  The epoxy plasticizer generally refers to an epoxy triglyceride composed of an alkyl epoxy stearate and soybean oil, but there are also so-called epoxy resins mainly made of bisphenol A and epichlorohydrin. Can be used.

  Specific examples of other plasticizers include benzoic acid esters of aliphatic polyols such as neopentyl glycol dibenzoate, diethylene glycol dibenzoate, triethylene glycol di-2-ethylbutyrate, fatty acid amides such as stearamide, oleic acid Examples thereof include aliphatic carboxylic acid esters such as butyl, oxyacid esters such as methyl acetylricinoleate and butyl acetylricinoleate, pentaerythritol, various sorbitols, polyacrylic acid esters, silicone oils, and paraffins.

  Among the plasticizers used in the present invention, at least one selected from polyester plasticizers and polyalkylene glycol plasticizers is preferable among those exemplified above. The plasticizer used in the present invention may be one kind or a combination of two or more kinds.

  Moreover, the compounding amount of the plasticizer is preferably 0.01 to 30 parts by weight, more preferably 0.1 to 20 parts by weight, with respect to 100 parts by weight of the resin derived from plant resources. It is particularly preferably 5 to 10 parts by weight.

  In the present invention, each of the crystal nucleating agent and the plasticizer may be used alone, but it is preferable to use both in combination.

  In the present invention, it is preferable that an aliphatic polyester resin and / or an aliphatic aromatic polyester resin other than the resin derived from plant resources is further blended in that the bubble size can be easily controlled.

  The aliphatic polyester resin of the present invention is not particularly limited, and a polymer mainly composed of an aliphatic hydroxycarboxylic acid, an aliphatic polyvalent carboxylic acid and an aliphatic polyhydric alcohol as main structural components. A polymer etc. are mentioned. Specifically, polymers having aliphatic hydroxycarboxylic acid as a main component include polyglycolic acid, poly-3-hydroxybutyric acid, poly-4-hydroxybutyric acid, poly-4-hydroxyvaleric acid, poly-3-hydroxyhexanoic acid. Or, polycaprolactone and the like, and examples of the polymer mainly composed of aliphatic polycarboxylic acid and aliphatic polyhydric alcohol include polyethylene adipate, polyethylene succinate, polybutylene adipate or polybutylene succinate. . These aliphatic polyesters can be used alone or in combination of two or more. Among these aliphatic polyesters, polybutylene succinate is preferable.

  The aliphatic aromatic polyester of the present invention is a polyester comprising an aliphatic dicarboxylic acid component, an aromatic dicarboxylic acid component, and an aliphatic diol component. Examples of the aliphatic dicarboxylic acid component include succinic acid, adipic acid, suberic acid, sebacic acid, and dodecanedioic acid. Examples of the aromatic dicarboxylic acid component include isophthalic acid, terephthalic acid, and 2,6-naphthalenedicarboxylic acid. Examples of the aliphatic diol include ethylene glycol, 1,4-butanediol, 1,3-propanediol, 1,4-cyclohexanedimethanol, and the like. The aromatic dicarboxylic acid component of the aliphatic aromatic polyester used in the present invention is preferably 60 mol% or less, more preferably 50 mol% or less, based on the total dicarboxylic acid component. Two or more types of aliphatic dicarboxylic acid component, aromatic dicarboxylic acid component, or aliphatic diol component can be used. In the present invention, it is preferable to use an aliphatic aromatic polyester resin composed of terephthalic acid, adipic acid, and 1,4-butanediol.

  In the present invention, the blending amount of the aliphatic polyester resin other than the plant resource-derived resin and the aliphatic aromatic polyester resin is not particularly limited, but when the plant resource-derived resin is 100 parts by weight, It is preferably 1 to 200 parts by weight, more preferably 5 to 150 parts by weight, and even more preferably 10 to 100 parts by weight.

  Moreover, in this invention, it is preferable to mix | blend an impact resistance improving agent. The impact resistance improver used in the present invention is not particularly limited as long as it can be used for improving the impact resistance of a thermoplastic resin. For example, at least one selected from the following various impact resistance improvers can be used.

  That is, specific examples of the impact modifier include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene-nonconjugated diene copolymer, ethylene-butene-1 copolymer, various acrylic rubbers, ethylene- Acrylic acid copolymer and its alkali metal salt (so-called ionomer), ethylene-glycidyl (meth) acrylate copolymer, ethylene-alkyl acrylate copolymer (for example, ethylene-ethyl acrylate copolymer, ethylene-acrylic) Acid butyl copolymer), acid-modified ethylene-propylene copolymer, diene rubber (for example, polybutadiene, polyisoprene, polychloroprene), copolymer of diene and vinyl monomer (for example, styrene-butadiene random copolymer, styrene) -Butadiene block Polymer, styrene-butadiene-styrene block copolymer, styrene-isoprene random copolymer, styrene-isoprene block copolymer, styrene-isoprene-styrene block copolymer, polybutadiene grafted with styrene, Butadiene-acrylonitrile copolymer), polyisobutylene, copolymer of isobutylene and butadiene or isoprene, natural rubber, thiocol rubber, polysulfide rubber, polyurethane rubber, polyether rubber, epichlorohydrin rubber, polyester elastomer, polyamide elastomer Etc.

  Furthermore, it is composed of those having various degrees of cross-linking, various micro structures such as those having a cis structure, a trans structure, etc., those having a vinyl group, etc., a core layer and one or more shell layers covering it, A so-called core-shell type multi-layered polymer in which adjacent layers are made of different polymers can also be used.

  The various (co) polymers listed in the above specific examples may be used as the impact resistance improver of the present invention, regardless of whether they are random copolymers, block copolymers, and graft copolymers. it can.

  Furthermore, in making these (co) polymers, it is also possible to copolymerize monomers such as other olefins, dienes, aromatic vinyl compounds, acrylic acid, acrylic ester and methacrylic ester. is there.

  Among these impact modifiers, a polymer containing an acrylic unit and a polymer containing a unit having an acid anhydride group and / or a glycidyl group are preferable. Preferable examples of the acrylic unit herein include methyl methacrylate units, methyl acrylate units, ethyl acrylate units and butyl acrylate units. Preferred examples of units having an acid anhydride group or glycidyl group May include maleic anhydride units and glycidyl methacrylate units.

  The impact resistance improver is a so-called core-shell type multi-layer polymer composed of a core layer and one or more shell layers covering the core layer, and adjacent layers are composed of different polymers. It is preferable that the polymer is a multilayer structure polymer containing methyl methacrylate units or methyl acrylate units in the shell layer. Such a multilayer structure polymer preferably contains an acrylic unit, or preferably contains a unit having an acid anhydride group and / or a glycidyl group. Preferred examples of the acrylic unit include a methyl methacrylate unit, an acrylic acid A methyl unit, an ethyl acrylate unit, and a butyl acrylate unit can be mentioned, As a suitable example of a unit which has an acid anhydride group and a glycidyl group, a maleic anhydride unit and a glycidyl methacrylate unit can be mentioned. In particular, the shell layer contains at least one selected from methyl methacrylate units, methyl acrylate units, maleic anhydride units and glycidyl methacrylate units, and includes butyl acrylate units, ethyl hexyl acrylate units, styrene units and butadiene units. A multilayer structure containing at least one selected from the above in the core layer is preferably used.

  The glass transition temperature of the impact resistance improver is preferably −20 ° C. or lower, and more preferably −30 ° C. or lower.

  The blending amount of the impact resistance improver is preferably in the range of 1 to 100 parts by weight and more preferably in the range of 2 to 50 parts by weight with respect to 100 parts by weight of the plant resource-derived resin.

  In the present invention, it is preferable to further blend an inorganic filler. As the inorganic filler used in the present invention, fibers, plates, granules, and powders that are usually used for reinforcing thermoplastic resins can be used. Specifically, glass fiber, asbestos fiber, carbon fiber, graphite fiber, metal fiber, potassium titanate whisker, aluminum borate whisker, magnesium-based whisker, silicon-based whisker, wollastonite, sepiolite, asbestos, slag fiber, zonolite, Elastadite, gypsum fiber, silica fiber, silica-alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber and boron fiber and other inorganic fillers, glass flakes, non-swellable mica, swellable mica, graphite, metal foil , Ceramic beads, talc, clay, mica, sericite, zeolite, bentonite, organic modified bentonite, organic modified montmorillonite, dolomite, kaolin, fine powdered silicic acid, feldspar powder, potassium titanate, shirasu balloon, calcium carbonate , Magnesium carbonate, barium sulfate, calcium oxide, aluminum oxide, titanium oxide, aluminum silicate, silicon oxide, gypsum, novaculite, include plate-like or granular inorganic fillers such as dawsonite and white clay. Among these inorganic fillers, glass fiber, wollastonite, mica and kaolin are particularly preferable. The aspect ratio of the fibrous filler is preferably 5 or more, more preferably 10 or more, and further preferably 20 or more.

  The inorganic filler may be coated or focused with a thermoplastic resin such as an ethylene / vinyl acetate copolymer or a thermosetting resin such as an epoxy resin, or a coupling agent such as aminosilane or epoxysilane. May be processed.

  Moreover, 1-100 weight part is preferable with respect to 100 weight part of resin derived from a plant resource, and, as for the compounding quantity of an inorganic filler, 5-50 weight part is more preferable.

  In the present invention, it is preferable to add a flame retardant. In the present invention, the flame retardant is not particularly limited as long as it is a substance added for the purpose of imparting flame retardancy to the resin. Specifically, brominated flame retardants, chlorinated flame retardants, phosphorus Flame retardants, nitrogen compound flame retardants, silicone flame retardants, other inorganic flame retardants, and the like, and it is preferable to use at least one selected from these, phosphorus flame retardants, nitrogen compound flame retardants, silicones It is more preferable to use a combination of at least two selected from a flame retardant and other inorganic flame retardants.

  The amount of the flame retardant is 0.01 to 100 parts by weight, more preferably 0.5 to 90 parts by weight, and further preferably 1 to 80 parts by weight with respect to 100 parts by weight of the plant resource-derived resin.

  In the present invention, it is preferable to further blend an antistatic agent in terms of imparting antistatic properties. Any known antistatic agent can be used in the present invention.

  In the antistatic agent of the present invention, its ionicity is not particularly limited, and any of cationic, anionic, zwitterionic and nonionic may be used, but thermal decomposition of a resin derived from plant resources Zwitterionic and nonionic are preferable, and nonionic is more preferable.

  Furthermore, it is preferable that the antistatic agent is biodegradable. Examples of such include Riken Master GSR-350 made by Riken Vitamin.

  0.1-10 weight part is preferable with respect to 100 weight part of resin derived from plant resources, and, as for the compounding quantity of said antistatic agent, 0.5-5 weight part is further more preferable.

  In the present invention, a stabilizer is preferably blended from the viewpoint that a resin composition excellent in mechanical properties, heat resistance, durability and the like can be obtained. As stabilizers, those usually used as stabilizers for thermoplastic resins can be used, but UV absorbers (benzophenone compounds, benzotriazole compounds, aromatic benzoate compounds, oxalic acid anilide compounds, cyanoacrylate compounds) Compounds and hindered amine compounds), heat stabilizers (hindered phenol compounds, phosphite compounds, thioether compounds) and the like are preferable. The blending amount of the stabilizer is preferably 0.01 to 3 parts by weight, and more preferably 0.03 to 2 parts by weight with respect to 100 parts by weight of the total of the polylactic acid resin and the naturally derived organic filler.

  In the present invention, a release agent is preferably blended from the viewpoint that a resin composition excellent in mechanical properties, moldability, heat resistance, durability, and the like can be obtained. As the mold release agent, those usually used for mold release agents for thermoplastic resins can be used. Specifically, fatty acids, fatty acid metal salts, oxy fatty acids, fatty acid esters, partially aliphatic saponified esters, paraffin, low molecular weight polyolefins, fatty acid amides, alkylene bis fatty acid amides, aliphatic ketones, fatty acid lower alcohol esters, fatty acid polyhydric alcohols Examples thereof include esters, fatty acid polyglycol esters, and modified silicones. By blending these, a molded product having excellent mechanical properties, moldability, heat resistance and durability can be obtained. The compounding amount of the release agent is preferably 0.01 to 3 parts by weight, and more preferably 0.03 to 2 parts by weight, with respect to 100 parts by weight in total of the resin derived from plant resources and the organic filler derived from nature.

  In the present invention, it is preferable to add an insect repellent and / or an antiseptic, and among them, the addition of an insect repellent is preferable because it can exterminate pests that lower the durability of materials such as termites and bark beetles. Of the insect repellents, those having a particularly effective anti-ant effect are also called anti-repellent agents. Further, as the insect repellent and / or antiseptic, those having further antibacterial properties are preferable. Insect repellents and / or preservatives can be used without any particular limitation, but pyrethroids such as borate, permethrin, and acrinatrin, etofenprox, and the like can be used for various purposes. Pyrethroid-like drugs such as silafluophene, compounds contained in cypress oil such as hinokitiol and tsuyopsen, or metal salts or metal complexes thereof, capric acid, turmeric, fipronil, imidacloprid, acetamiprid, etc. are preferred, and cypress oil such as hinokitiol and tsuyopsen Or a metal salt or metal complex thereof, capric acid, turmeric, fipronil, imidacloprid, or acetamiprid, and hinokitiol or a metal salt or metal complex thereof, Alkenyl, more preferably imidacloprid.

  The addition amount of the insect repellent and / or preservative is not particularly limited, but is preferably 0.01 to 15 parts by weight, and 0.1 to 10 parts by weight with respect to 100 parts by weight of the resin derived from plant resources. Part is more preferable, and further 0.5 to 5 parts by weight is most preferable.

  In this invention, in the range which does not impair the objective of this invention, 1 type, or 2 or more types, such as a normal additive other than the above, for example, a coloring agent containing a lubricant, dye, and a pigment, can further be contained.

  The composition of the present invention is not limited to the purpose of the present invention, and other thermoplastic resins (for example, acrylic resin, polyamide resin, aromatic polyester resin, polyacetal resin, polyphenylene sulfide resin, polyether ether ketone resin, polysulfone) Resin, polyphenylene oxide resin, polyimide resin, polyetherimide resin, etc.), thermosetting resin (for example, phenol resin, melamine resin, other polyester resin, silicone resin, etc.) can also be contained.

  As a method for producing the foam of the present invention, any of a melt foaming method, a solid phase foaming method and a cast foaming method may be used, but the melt foaming method is preferred because it can be easily carried out. Specifically, a plant resource-derived resin, preferably a polylactic acid resin, a naturally-derived organic filler and a foaming agent are melt-kneaded to form a foam. The melt kneading may be performed under normal pressure or under pressure, but is preferably melt-kneaded under pressure and then extruded under atmospheric pressure or injected into a mold to form a foam.

  In the present invention, the method of melt-kneading is not particularly limited. For example, after pre-blending a plant-derived resin, a naturally-occurring organic filler, a foaming agent, and other additives as necessary, a plant-resource-derived Extrusion of single-screw extruder, twin-screw extruder, single-screw / double-screw extruder, multi-screw extruder, tandem-type extruder connecting two single-screws and / or two twin-screws above the melting point of the resin Foam extrusion molding method that is uniformly melt-kneaded using a machine to make an extruded foam, foam injection molding method that is directly melt-kneaded using an injection molding machine to make a foam, and a resin derived from plant resources uniformly using an extruder Then, after melt-kneading a naturally-derived organic filler to obtain a resin composition, a foaming agent, preferably a plant resource-derived resin, a foaming agent or a foaming agent and a foaming auxiliary agent at a temperature below the decomposition temperature of the foaming agent, Preferably 50-200 ° C, more Mashiku may be preferably used any methods such as a method to foam by using a press or injection molding machine by blending a foaming agent master batch prepared by melt-kneading at a temperature range of 100 to 180 ° C.. In addition, when using fine powder as a raw material, the method of adding after compressing a fine powder, the method of supplying to a hopper independently from another additive, etc. are preferable.

  In this invention, 100-250 degreeC is preferable, as for the preset temperature of an extruder or an injection molding machine, 120-240 degreeC is more preferable, 140-230 degreeC is further more preferable, and 160-220 degreeC is the most preferable. The set temperature refers to the cylinder set temperature. The set temperature is set so that the resin temperature, preferably the resin temperature near the inner wall of the cylinder is 160 to 230 ° C., preferably 170 to 210 ° C., more preferably 175 to 200 ° C.

  In the present invention, the screw rotation speed of the extruder or the injection molding machine is not particularly limited, but is preferably 10 to 500 rpm, more preferably 30 to 350 rpm from the viewpoint of suppressing an increase in the resin temperature due to shearing heat generation. 50 to 250 rpm is more preferable, and 70 to 200 rpm is particularly preferable.

  In the present invention, the ratio (L / D) of the length (L) of the screw of the extruder to the diameter (D) of the screw is not particularly limited, but is 20 to 20 from the viewpoint of the dispersibility of the naturally derived organic filler. 80 is preferable, 25 to 70 is preferable, 30 to 60 is more preferable, and 35 to 50 is particularly preferable.

  In the present invention, the mold temperature in the case of foam injection molding is preferably 30 ° C or higher, more preferably 60 ° C or higher, further preferably 70 ° C or higher, from the viewpoint of crystallization, from the viewpoint of deformation of the test piece, 140 degrees C or less is preferable, 120 degrees C or less is more preferable, and 110 degrees C or less is more preferable.

  In the present invention, it is preferable to introduce an inert gas such as nitrogen because a foam having a stable and good color tone can be obtained.

  In the present invention, as a method of supplying raw materials to an extruder or an injection molding machine, a method of directly supplying each raw material individually, a method of supplying all raw materials in a lump after premixing, a Henschel mixer, etc. Either a method of supplying the raw material after making it agglomerated with a high speed mixer or a method of supplying it after pelletizing with an extruder or the like can be used, but operability and dispersion of organic fillers derived from nature From the viewpoint of properties, a method of directly supplying each raw material individually and a method of supplying all raw materials in a lump after premixing them are preferable. Moreover, it is preferable to supply a raw material using a weight feeder from the point of extrusion stability.

  In the present invention, when using a method in which all raw materials are mixed in advance and then fed together, the extruder or injection molding machine can be operated stably, and the dispersibility of the natural organic filler can be increased. It is preferable to blend using a blender such as a V blender, a ribbon blender, a tumbler blender, a screw blender, and a Henschel mixer as premixing because it can be improved. When this method is used, the raw material may be either granular or powdery, but is preferably powdery from the viewpoint of mixing properties.

  The foam of the present invention has a foaming ratio of 1.02 to 15 times. Here, the expansion ratio can be determined from the raw material resin composition density / foam density. In addition, from the viewpoint of heat resistance, the expansion ratio is more preferably 1.1 times or more, more preferably 1.3 times or more, particularly preferably 1.4 times or more, and most preferably 1.45 times or more. . Further, the upper limit is preferably 10 times or less, more preferably 8 times or less, still more preferably 5 times or less, particularly preferably 3 times or less, and 2 times or less. Is most preferred. If the expansion ratio is less than 1.02, the lightness is not sufficient, and if it exceeds 15 times, not only the heat resistance is lowered, but also it becomes difficult to obtain a stable product, which is not preferable. The foam having the expansion ratio can be obtained by using a preferable foaming agent in a preferable addition amount and utilizing a preferable manufacturing method. Here, the density of the raw material resin composition is the density of the raw material resin composition in the unfoamed state, and if the used raw material is known, it is calculated according to the composition ratio of the used raw material. Can do. Further, even when the raw material used is not known, it can be obtained from a product obtained by solidifying an unfoamed product by removing bubbles after the foamed raw material resin composition is in a molten state.

In the present invention, the lightness can be determined from the foam density. Foam density is not particularly limited but is preferably 0.03~1.25g / cm ^3, more preferably 0.1 g / cm ³ or more, more preferably 0.3 g / cm ³ or more 0.4 g / cm ³ or more is particularly preferable, and 0.5 g / cm ³ or more is most preferable. Further, 1.05 g / cm ³ or less is more preferable, 1.00 g / cm ³ or less is more preferable, 0.95 g / cm ³ or less is particularly preferable, and 0.90 g / cm ³ or less is most preferable. When the foam density is less than 0.03 g / cm ³ , poor appearance and reduced strength are caused, and when it exceeds 1.25 g / cm ³ , the effect of weight reduction is small, which is not preferable. The foam having the above-mentioned foam density can be obtained by using a preferable foaming agent in a preferable addition amount and utilizing a preferable manufacturing method. The foam density can be obtained from the weight of the foam (g) / the volume of the foam (cm ³ ) using the weight of the foam and the volume determined by the submerging method.

  The foam size of the foam of the present invention is not particularly limited, but is preferably 0.1 to 1000 μm, more preferably 1 to 700 μm, further preferably 5 to 500 μm, and particularly preferably 10 to 300 μm from the viewpoint of appearance. If the bubble size is less than 0.1 μm or more than 1000 μm, the effect of foaming is impaired, and the appearance is poor and the strength is lowered. The foam having the above cell size can be obtained by using a preferable foaming agent and the above-mentioned additives such as a preferable crystallization accelerator and an aliphatic aromatic polyester in a preferable addition amount and utilizing a preferable production method. The bubble size is an average value of arbitrary 10 bubbles, preferably 100 bubbles, in which the inner layer portion of the cross section of the foam can be observed with an optical microscope at 5 times or more, preferably 50 times.

  Among the bubbles that can be observed by the above method, the difference between the minimum bubble size and the maximum bubble size is preferably 1000 μm or less, more preferably 800 μm or less, further preferably 500 μm or less, and 300 μm or less. It is particularly preferred that If the difference between the minimum bubble size and the maximum bubble size is out of the above range, the effect of foaming is impaired, which leads to poor appearance and reduced strength. The foam having the above cell size can be obtained by using a preferable foaming agent and the above-mentioned additives such as a preferable crystallization accelerator and an aliphatic aromatic polyester in a preferable addition amount and utilizing a preferable production method.

  In the present invention, when the resin derived from plant resources is a polylactic acid resin, it is preferable that the crystallization temperature (Tc) at the time of cooling derived from the polylactic acid resin can be observed. Here, Tc is a crystallization temperature at the time of temperature decrease derived from a polylactic acid resin measured at a temperature decrease rate of 20 ° C./min after the temperature was increased to 200 ° C. by a differential scanning calorimeter (DSC). Tc is not particularly limited, but is preferably 100 ° C. or higher, more preferably 105 ° C. or higher, and further preferably 110 ° C. or higher from the viewpoint of moldability.

  In the present invention, when the resin derived from plant resources is a polylactic acid resin, it is preferable that the crystallization temperature (Tcc) at the time of temperature increase derived from the polylactic acid resin is not observed. When Tcc is observed, the crystallization enthalpy (ΔHcc) is preferably 10 J / g or less, more preferably 5 J / g or less, and even more preferably 1 J / g or less. Here, Tcc and ΔHcc are a crystallization temperature and a crystallization enthalpy derived from a polylactic acid resin obtained by measuring a molded product with a differential scanning calorimeter (DSC) at a temperature rising rate of 20 ° C./min.

  In the present invention, when the resin derived from plant resources is a polylactic acid resin, the relative crystallization obtained from the crystal melting enthalpy (ΔHm) derived from the polylactic acid resin and the crystallization enthalpy (ΔHcc) at the time of temperature rise The degree [{(ΔHm−ΔHcc) / ΔHm} × 100] is preferably 70% or more, more preferably 90% or more, further preferably 93% or more, and 96% or more. Particularly preferred is 100%. Here, ΔHcc is the crystallization enthalpy derived from polylactic acid resin measured by DSC at a temperature rising rate of 20 ° C./min, and ΔHm is derived from polylactic acid resin measured by DSC at a temperature rising rate of 20 ° C./min. In the first measurement (1stRUN), the temperature was increased from 30 ° C. to 200 ° C. at a temperature increase rate of 20 ° C./min, and then cooled to 30 ° C. at a temperature decrease rate of 20 ° C./min. When the temperature is increased from 30 ° C. to 200 ° C. at a temperature increase rate of 20 ° C./min in the second measurement (2nd RUN), the crystal melting enthalpy measured at 2 nd RUN is preferable.

  The foam having such crystallization characteristics can be made into a foam excellent in heat resistance and dimensional stability, and can be achieved by using a naturally-derived organic filler having the above-mentioned preferred embodiments.

  In the present invention, the resistance to pulling out the nail (nail holding force) is not particularly limited, but it is preferably 200 N or more and 350 N or more from the viewpoint that it has excellent nail holding properties and can be used for various applications. Is more preferably 500N or more, and most preferably 600N or more. The upper limit is not particularly limited. The resistance to pulling out the nail of the present invention is such that N45 nails are vertically driven 30 mm vertically into each test piece, which is an arbitrarily selected five foams (one nail is driven in the center) at a speed of 10 mm / min. The average value of the maximum load when pulling out vertically was taken as the nail holding force. When the thickness of the foam is less than 30 mm, the nail is driven through the foam and 30 mm from the tip of the nail. Further, quality stability can be judged using the standard deviation (σ), σ is preferably less than 60, σ is more preferably less than 45, and σ is less than 30. preferable.

  Such a foam having nail retention and quality stability uses a resin derived from plant resources having a preferred weight average molecular weight, and a preferred foaming agent is selected by selecting a preferred foaming agent, and a more preferable end-blocking agent and / or It can be obtained by using a preferred production method using a crystallization accelerator.

  In the present invention, the wood screw holding force is not particularly limited, but it is preferably 200 N or more, more preferably 500 N or more, from the viewpoint that it is excellent in wood screw holding properties and can be used for various applications. , 900N or more, and more preferably 1000N or more. The upper limit is not particularly limited. According to JIS A5905, the wood screw holding force of the present invention is 11 mm screwed into a test piece which is a foam selected arbitrarily 5 pieces, each having a nominal diameter of 2.7 mm and a length of 16 mm. The average value of the maximum load when pulling out vertically at a speed of 2 mm / min was defined as the wood screw holding force. When the thickness of the foam is less than 11 mm, the nail is driven through the foam and 11 mm from the tip of the wood screw.

  Such a foam having wood screw retention uses a plant resource-derived resin having a preferred weight average molecular weight, selects a preferred foaming agent to obtain a preferred foaming ratio, and further preferred end-capping agents and / or crystallization accelerators. And can be obtained by utilizing a preferable production method.

The foam of the present invention has various shapes such as a board shape, a sheet shape, a film shape, a plate shape, a rod shape, a column shape, a box shape, a lump shape, a tube shape, a fiber shape, a net shape, a particle shape, and a complex shape. When the foam of the present invention has a board shape, the thickness is preferably 1 to 30 mm, more preferably 2 to 25 mm, and even more preferably 5 to 20 mm. If the thickness is less than 1 mm, the number of bubbles is reduced and the lightness is not sufficient. If the thickness exceeds 30 mm, it is difficult to control the expansion ratio and the bubble size, and it is difficult to obtain a good product having a uniform thickness. Therefore, it is not preferable.

  The foam of the present invention includes electrical / electronic parts (such as various housings, gears, and gears), building materials, civil engineering materials, agricultural materials, automobile parts (such as interior and exterior parts), and packaging materials (such as various containers and cushioning materials). It can be used for various purposes such as daily life materials (daily necessities, sports equipment, etc.), and materials for gaming machines.

  Specifically, notebook personal computer housings and internal parts, CRT display housings and internal parts, printer housings and internal parts, mobile terminal housings and internal parts such as mobile phones, mobile personal computers and handheld mobiles, recording media (CD, DVD, PD, FDD, etc.) Drive housings and internal parts, copier housings and internal parts, facsimile housings and internal parts, parabolic antennas, and other electric / electronic parts. Furthermore, audio equipment parts such as VTR parts, TV parts, irons, hair dryers, rice cooker parts, microwave oven parts, acoustic parts, video cameras, audio / laser discs (registered trademark) / compact discs, lighting parts, refrigerator parts, Examples include home and office electrical product parts such as air conditioner parts, typewriter parts, and word processor parts. Also, housings and internal parts of electronic musical instruments, home game machines, portable game machines, various gears, various cases, sensors, LEP lamps, connectors, sockets, resistors, relay cases, motor cases, switches, capacitors, variable capacitor cases , Optical pickups, oscillators, various terminal boards, transformers, plugs, printed wiring boards, tuners, speakers, microphones, headphones, small motors, magnetic head bases, power modules, semiconductors, liquid crystals, FDD carriages, FDD chassis, motor brushes Electric and electronic parts such as holders, transformer members, coil bobbins, sash doors, blind curtain parts, piping joints, curtain liners, blind parts, gas meter parts, water meter parts, water heater parts, roof panels Insulating wall, adjuster, plastic bundle, ceiling fishing tackle, stairs, door, floor, pillar, foundation, beam, baseboard, flooring, ceiling material, shoji, fence, window frame, door, deck material, chest , Furniture such as desks, chairs, various shelves, fishing line, fishing nets, seaweed aquaculture nets, fishing bait bags and other fishery related materials, vegetation nets, vegetation mats, grass protection bags, grass protection nets, curing sheets, slope protection sheets , Fly ash holding sheet, drain sheet, water retention sheet, sludge / sludge dewatering bag, concrete formwork, scaffolding board, sheet pile, pile, and other civil engineering related materials, air flow meter, air pump, thermostat housing, engine mount, ignition hobbin, ignition case , Clutch bobbin, sensor housing, idle speed control valve, vacuum switching valve, ECU housing, Vacuum pump case, inhibitor switch, rotation sensor, acceleration sensor, distributor cap, coil base, actuator case for ABS, top and bottom of radiator tank, cooling fan, fan shroud, engine cover, cylinder head cover, oil cap, oil pan, Oil filter, fuel cap, fuel strainer, distributor cap, vapor canister housing, air cleaner housing, timing belt cover, brake booster parts, various cases, various tubes, various tanks, various hoses, various clips, various valves, various pipes, etc. Car underhood parts, torque control levers, safety belt parts, register braces Door, washer lever, window regulator handle, knob for window regulator handle, passing light lever, sun visor bracket, various motor housings, spare tire covers, door trims and other automotive interior parts, roof rails, fenders, garnishes, bumpers, door mirror stays, Automobile parts such as spoiler, hood louver, wheel cover, wheel cap, grill apron cover frame, lamp reflector, lamp bezel, door handle, wire harness connector, SMJ connector, PCB connector, door grommet connector, various automotive connectors, Gears, screws, springs, bearings, levers, key stems, cams, ratchets, rollers, water supply parts, toy parts, fans, Guns, pipes, cleaning jigs, motor parts, microscopes, binoculars, cameras, clocks and other mechanical parts, multi-films, tunnel films, bird protection sheets, vegetation protection nonwoven fabrics, seedling pots, vegetation piles, seed string tape , Germination sheet, house lining sheet, agricultural PVC film stopper, slow-release fertilizer, root-proof sheet, garden net, insect net, young tree net, print laminate, fertilizer bag, sample bag, sandbag, animal damage Agricultural materials such as prevention nets, incentive straps, windproof nets, sanitary products such as disposable diapers, sanitary wrapping materials, non-woven fabrics for medical use (stitching reinforcements, anti-adhesion films, prosthetic repair materials), wound dressing materials, wound tape bandages, Sticky base fabric, surgical suture, fracture reinforcement, medical supplies such as medical film, calendar, stationery, clothing, food packaging film, tray, blister, knife, foam Containers and tableware such as cups, spoons, tubes, plastic cans, pouches, containers, tanks, baskets, hot fill containers, containers for microwave cooking cosmetic containers, cushioning materials, pallets, containers and other transport and storage materials, Paper laminate, shampoo bottle, beverage bottle, wrap, cup, candy packaging, shrink label, lid material, window envelope, fruit basket, hand cut tape, easy peel packaging, egg pack, HDD packaging, compost bag, recording media Containers and packaging such as packaging, shopping bags, wrapping films for electrical and electronic parts, curtains, chairs, carpets, table cloths, futons, wallpaper, and other interior goods, carrier tape, print laminates, thermal stencil printing films Release film, porous film, container bag, Credit card, cash card, ID card, IC card, conductive embossed tape, IC tray, golf tee, garbage bag, plastic bag, various nets, toothbrush, stationery, draining net, body towel, hand towel, tea pack, drain As pachinko parts such as filters, clear files, bags, chairs, tables, cooler boxes, kumade, hose reels, planters, hose nozzles, pachinko machine gauge panels and frame materials, mahjong machines, billiard machines, etc. Useful.

Hereinafter, the present invention will be described in more detail by way of examples. All the parts in the examples are based on weight. Moreover, the raw material used and the code | symbol in a table | surface are shown below.
(A) Resin derived from plant resources (A-1) Polylactic acid (D-form 1.2%, PMMA equivalent weight average molecular weight 170,000)
(A-2) Polyhydroxy (butyrate / valerate) (Biopol manufactured by Monsanto)
(A-3) Polylactic acid (D-form 1.5%, PMMA equivalent weight average molecular weight 95,000)
(B) Naturally derived organic filler (B-1) Waste paper powder obtained by pulverizing 1 mm-thick paperboard (B-2) Waste paper powder obtained by defibrating newspaper (B-3) Fiber length 1-crushed A4 copy paper 5 mm paper dust (B-4) Wood flour (Lettnomeier Lignocell C-300G)
(B-5) Kenaf fiber having a fiber length of 1 to 10 mm (B-6) Hemp fiber pellets having a length of 50 mm or less and a diameter of 5 mm (C) Foaming agent (C-1) Azodicarbonamide-based foaming agent (Sankyo Kasei) Cell microphone)
(C-2) Baking soda-based foaming agent (manufactured by Eiwa Chemical Industries)
(C-3) azodicarbonamide-based foaming agent (melting 30 parts by weight of azodicarbonamide (manufactured by Eiwa Kasei Kogyo Co., Ltd., decomposition temperature 205 ° C.) at 175 ° C. with respect to 100 parts by weight of resin (A-1) derived from plant resources Kneading foam masterbatch)
(D) Carboxyl terminal reactive terminal blocker (D-1) Carbodiimide compound (Nisshinbo Carbodilite HMV-8CA)
(D-2) Diglycidyl terephthalate (Denacol EX-711 manufactured by Nagase Kasei)
(E) Crystallization accelerator (E-1) Talc (Hitron made by Takehara Chemical)
(E-2) Polyethylene glycol (PEG 4000 manufactured by Sanyo Chemical)
(F) Aliphatic aromatic polyester other than resin derived from plant resources (F-1) Polybutylene (terephthalate / adipate) (Ecoflex manufactured by BASF).

[Examples 1 to 18, Comparative Examples 1 to 4]
Various materials such as plant resource-derived resins shown in Table 1 are mixed in the proportions shown in Table 1, using a 50 mm diameter twin screw extruder (L / D = 35), cylinder temperature 190 ° C., screw rotation Melt-kneading extrusion was performed under conditions of several hundred rpm and a molding die temperature of 180 ° C. to obtain a foam having a width of 300 mm and a thickness of 3 mm.

The obtained foam is cut into a size of 100 mm × 100 mm × 3 mm, the volume by submersion method is calculated up to 3 significant figures, the density (foam density) is calculated, and the lightness is calculated from the value. Judgment was made according to the following criteria.
◎: density of 0.05 g / cm ³ or more 0.85 g / cm ³ or less ○: density of 0.85 g / cm ³ Ultra 1.25 g / cm ³ or less ×: Density is more than 1.25 g / cm ³ Also, the raw material The expansion ratio was determined from the resin composition density / foam density.

  Further, the foam cut out to the above-mentioned size was cooled from 200 ° C. to 30 ° C. at a temperature lowering rate of 20 ° C./min in a 10 mg sample under a nitrogen atmosphere using a Perkin Elmer DSC7. Asked.

Further, regarding the variation in the bubble size, the inner layer portion of the cross section of the foam cut out to the above size was observed at 50 times using an optical microscope, and for any 10 pieces, from the difference between the minimum bubble size and the maximum bubble size, Judged by criteria.
A: Small variation and excellent uniformity (difference is 500 μm or less).
○: Although there is some variation, it is almost uniform (the difference is more than 500 μm and 1000 μm or less).
(Triangle | delta): There exists variation and it is a little inferior in uniformity (a difference is more than 1000 micrometers and 1500 micrometers or less).
×: Large variation and poor uniformity (difference exceeds 1500 μm).

Further, the foam cut out to the above size was treated with a hot air dryer at 100 ° C. for 50 hours, and then deformation (dry heat deformation) such as warpage and shrinkage was visually observed and judged according to the following criteria.
A: No deformation (warp or shrinkage is 0.3 mm or less).
○: Slightly deformed (warp or shrinkage is more than 0.3 mm and 1.0 mm or less).
Δ: Slightly large deformation (warp or shrinkage is more than 1.0 mm and 1.5 mm or less).
X: Large deformation (warp or shrinkage exceeds 1.5 mm).

In addition, the foam cut out to the above size is visually observed for deformation (wet heat deformation) such as warpage and shrinkage after being treated for 50 hours at a temperature of 60 ° C. and a relative humidity of 95% using a thermostatic chamber. The determination was made according to the following criteria.
A: No deformation (warp or shrinkage is 0.3 mm or less).
○: Slightly deformed (warp or shrinkage is more than 0.3 mm and 1.0 mm or less).
Δ: Slightly large deformation (warp or shrinkage is more than 1.0 mm and 1.5 mm or less).
X: Large deformation (warp or shrinkage exceeds 1.5 mm).

  Also, for any five foams cut out to the above size, each N45 nail is driven 30 mm (one nail is driven in the center), and the average value of the maximum load required for vertical extraction at 10 mm / min is obtained. The nail pulling resistance (nail holding force) was used. The standard deviation (σ) was used to determine quality stability according to the following criteria.

A: σ <30
○: 30 ≦ σ <45
Δ: 45 ≦ σ <60
×: 60 ≦ σ
These results are also shown in Table 1.

  From the results in Table 1, it can be seen that the foam of the present invention is excellent in light weight and heat resistance. In addition, the foam of the present invention is excellent in nail retention, particularly when a terminal blocker is blended and a foaming agent master batch is used, the nail retention strength σ is small, and a stable quality foam. It can be seen that can be obtained.

  Moreover, about the used paper powder (B-1 and B-2) used in the Example, 10 g of samples were taken and processed in an electric furnace at 450 ° C. for 12 hours to determine the amount of ash. Furthermore, the obtained ash was analyzed using a fluorescent X-ray apparatus. The analysis results are shown in Table 2.

  From the results of Tables 1 and 2, it was found that heat resistance was particularly improved by using paper powder containing aluminum, silicon, calcium, sulfur, and magnesium and having an aluminum content twice or more that of magnesium. It turns out that it is excellent.

[Examples 19 to 35, Comparative Examples 5 to 8]
A resin derived from plant resources and a natural organic filler are mixed in the proportions shown in Table 3, and melt-kneaded using a 50 mm diameter twin screw extruder at a cylinder temperature of 180 ° C. to obtain a resin composition. It was. A foaming agent was blended in the obtained resin composition, and injection molding was performed under the conditions of a cylinder temperature of 210 ° C. and a mold temperature of 85 ° C. to obtain a molded product having a thickness of 20 mm, a length of 150 mm, and a width of 150 mm.

  The obtained foam was cut into a size of 100 mm × 100 mm, and evaluated for lightness, foaming ratio, Tc, bubble size variation, dry heat deformation, and wet heat deformation according to the same criteria as in Examples 1-18.

  Necessary when 11 mm of wood screws of a nominal diameter of 2.7 mm and a length of 16 mm are screwed into each of the five foams cut out to the above sizes (one wood screw is screwed in the center) and pulled out vertically at a speed of 2 mm / min. The obtained maximum load was determined, and the average value was defined as the wood screw holding force.

  N45 nails are driven 30 mm each into any of the five foams cut to the above size (one nail is driven in the center), and the maximum load required when pulling out vertically at a speed of 10 mm / min is determined. The value was defined as the resistance to pulling out the nail (nail holding force). The standard deviation (σ) was used to determine quality stability according to the following criteria.

A: σ <30
○: 30 ≦ σ <45
Δ: 45 ≦ σ <60
×: 60 ≦ σ
These results are shown in Table 3.

  From the results in Table 3, it can be seen that the foam of the present invention is excellent in light weight and heat resistance. In addition, wood boards such as particle boards and MDF having the same thickness generally have a wood screw holding force of about 300 to 500 N and a nail holding force of about 300 to 600 N. Therefore, the foam of the present invention has a wood screw holding force. It can be seen that it is particularly excellent in the property and nail retention. Further, it can be seen that when a terminal blocking agent is blended and a foaming agent master batch is used, the σ of the nail holding force is small, and a foam with stable quality can be obtained.

Claims (7)

A foam comprising a resin composition obtained by blending a plant resource-derived resin and a naturally-derived organic filler, the foaming ratio being 1.02 to 15 times. The foam according to claim 1, wherein the plant resource-derived resin contains a polylactic acid resin, and the polylactic acid resin has a weight average molecular weight of 100,000 or more. The foam according to claim 1, wherein the plant resource-derived resin is a polylactic acid resin, and the crystallization temperature (Tc) when the temperature is lowered derived from the polylactic acid resin is 100 ° C or higher. The foam according to claim 1, wherein the resin composition further comprises a carboxyl group-reactive end-blocking agent. The foam according to claim 1, wherein the naturally-derived organic filler contains paper powder, and the paper powder contains aluminum, silicon, calcium, and sulfur. A method for producing a foam, characterized by melt-kneading a resin derived from plant resources, a natural organic filler and a foaming agent to obtain a foam having an expansion ratio of 1.02 to 15 times. The method for producing a foam according to claim 6, wherein a foaming agent master batch obtained by melt-kneading a resin derived from plant resources and a foaming agent at a temperature lower than the decomposition temperature of the foaming agent is used as the foaming agent. .