JP2011079937A - Modified silicone resin foam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a modified silicone resin foam having a small compressive residual strain at high temperatures and good flexibility. <P>SOLUTION: The modified silicone resin foam is obtained by curing an expandable liquid resin composition comprising a curing agent (A) having at least two hydrosilyl groups in the molecular chain, a polymer (B) having at least one alkenyl group in the molecular chain and an oxyalkylene type unit as a repeating unit constituting the main chain, a hydrosilylation catalyst (C), a blowing agent (D), and a plasticizer (E) having an oxyalkylene type unit as a repeating unit constituting the main chain, an average of less than one alkenyl group in the molecular chain, and a number average molecular weight of not less than 1,000. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a foam made of a modified silicone resin.

  As foams of polymer compounds, foams using thermoplastic resins such as polystyrene, polyethylene, polypropylene, and polyvinyl chloride are used as beads, sheets, or boards, and have characteristics such as heat insulation, lightness, and buffering properties. It is used in the civil engineering and construction field, packaging field, home appliance field, and automobile field. All of these require large-scale equipment to make a foam. These are also generally rigid foams.

  On the other hand, a polyurethane foam is well known as a foam using a thermosetting resin obtained by curing and foaming a liquid resin composition. Polyurethane foams can be easily molded with a small-scale facility, and soft foams can be produced, but have the disadvantage of using an isocyanate that is toxic. Polyurethane foams cannot be said to have sufficient flexibility and cannot be said to have good touch. Therefore, there is a demand for a foam that is easy to mold, flexible, and has good tactile sensation, without using a material that may be toxic.

The present inventors have proposed a foam using a modified silicone resin as a foam that is easy to mold, flexible, and has good tactile sensation without using a material that is toxic. (Patent Document 1) . The modified silicone resin foam is superior to the soft foam of polyurethane, which is a general soft foam. Expansion to bedding and various cushioning materials is expected. Moreover, when using for bedding etc., a low density foam is anticipated. The modified silicone resin foam specifically disclosed in Patent Document 1 has a foam density of 171 kg / m ³ or more.

International Publication No. 2008/117734

  While the inventors have made various studies on the modified silicone resin foam described in Patent Document 1, it has been found that the modified silicone resin foam may have a large compressive residual strain at high temperatures. Therefore, in order to reduce the compressive residual strain, for example, when heat curing of the modified silicone resin foam is performed, although the compressive residual strain is improved, the hardness increases, and the modified silicone resin foam inherently has flexibility. It was found that sexuality and tactile sensation deteriorate. Accordingly, an object of the present invention is to provide a modified silicone resin foam having a small compressive residual strain at high temperature and good flexibility.

  As a result of intensive studies for solving the above-mentioned problems, the inventors of the present invention have a modified silicone resin foam in which the repeating unit constituting the main chain is composed of oxyalkylene units, and an average of one unit in the molecular chain. By containing a plasticizer having an alkenyl group of less than 1,000 and a number average molecular weight of 1000 or more, the compressive residual strain is reduced without impairing the advantage of flexibility inherently possessed by the modified silicone resin foam. The inventors found that a small modified silicone resin foam could be obtained, and completed the present invention. Furthermore, it has been found that a low-density modified silicone resin foam can be obtained by containing a polymer having at least one alkenyl group and at least one hydroxyl group in the molecular chain as a foaming aid. .

That is, this invention consists of the following structures.
[1] A curing agent (A) having at least two hydrosilyl groups in the molecular chain, at least one alkenyl group in the molecular chain, and a repeating unit constituting the main chain consisting of oxyalkylene units. The combination (B), hydrosilylation catalyst (C), blowing agent (D), the repeating unit constituting the main chain consists of oxyalkylene units, and has an average of less than one alkenyl group in the molecular chain, A modified silicone resin foam obtained by curing a foamable liquid resin composition comprising a plasticizer (F) having a number average molecular weight of 1000 or more.
[2] The number average molecular weight of the polymer (B) having at least one alkenyl group in the molecular chain and in which the repeating unit constituting the main chain is an oxyalkylene unit is 15000 or more. Modified silicone resin foam.
[3] The foaming agent (D) is an active hydrogen compound having no alkenyl group in the molecular chain, having a number average molecular weight of 1000 or less and a hydroxyl group equivalent of 1.0 mmol / g or more. The modified silicone resin foam described.
[4] A foamable liquid resin composition comprising a compound (E) having at least one alkenyl group and at least one hydroxyl group in the molecular chain as a foaming aid is cured [1]. [3] The modified silicone resin foam according to any one of [1] to [3].
[5] The modified silicone resin foam according to any one of [1] to [4], wherein a compressive residual strain when compressed 75% under a condition of 60 ° C. for 24 hours is 8% or less.
[6] The modified silicone resin foam according to any one of [1] to [5], wherein the density is 150 kg / m ³ or less.
[7] The modified silicone resin foam according to any one of [1] to [6], wherein the hardness at 40% compression is 30 N or less.
[8] A bedding comprising the modified silicone resin foam according to any one of [1] to [7].

  The modified silicone resin foam of the present invention has a small compressive residual strain at a high temperature and has flexibility. Therefore, when used as a bedding such as a pillow or various cushion materials, a soft sink can be obtained, and at the same time, distortion can be suppressed and excellent restoration can be obtained.

  The modified silicone resin foam constituting the foam of the present invention has a curing agent (A) having at least two hydrosilyl groups in the molecular chain, at least one alkenyl group in the molecular chain, and a main chain. The polymer (B) in which the repeating unit is composed of an oxyalkylene-based unit, the hydrosilylation catalyst (C), the foaming agent (D), the repeating unit constituting the main chain is composed of an oxyalkylene-based unit, and is averaged in the molecular chain And a foamable liquid resin composition comprising a plasticizer (F) having less than one alkenyl group and a number average molecular weight of 1000 or more is cured.

  In the modified silicone resin foam of the present invention, the repeating unit constituting the main chain is composed of an oxyalkylene unit, has an average of less than one alkenyl group in the molecular chain, and has a number average molecular weight of 1000 or more. It contains a plasticizer (F) (hereinafter sometimes simply referred to as “plasticizer”). The plasticizer refers to a compound that can improve molding processability and impart flexibility.

  The modified silicone resin foam of the present invention contains a plasticizer (F), so that excessive hardness increase and tactile deterioration are suppressed even after heat-curing the modified silicone resin foam to reduce compressive residual strain. It is flexible and has a small compressive residual strain.

  In the plasticizer of the present invention, the repeating unit constituting the main chain is composed of an oxyalkylene unit. Specific examples of the main chain include polyethylene oxide, polypropylene oxide, polybutylene oxide; two or more random or block copolymers selected from ethylene oxide, propylene oxide, and butylene oxide, and these are used alone. You may use 2 or more types together. Of these, polypropylene oxide is preferable from the viewpoint of compatibility with the polymer (B) described later.

  The molecular weight of the plasticizer is 1000 or more in terms of number average molecular weight from the viewpoint of flexibility of the resulting modified silicone resin foam and prevention of outflow of the plasticizer out of the system, and preferably 3000 or more. If the number average molecular weight is too low, the plasticizer will flow out of the system over time due to heat, compression, etc., and the initial physical properties cannot be maintained over a long period of time, and there is a concern that the tactile sensation will be adversely affected. The upper limit is not particularly limited, but if the number average molecular weight is too high, the viscosity becomes high and workability deteriorates, so it is preferably 50000 or less, and more preferably 30000 or less. In addition, if the plasticizer of this invention can provide a softness | flexibility to a modified silicone resin foam, there will be no limitation in particular even if it is linear or branched.

  The plasticizer (F) used in the present invention has an average of less than 1 alkenyl group in the molecular chain. Preferably, it does not have an alkenyl group in the molecular chain. If the plasticizer has an average of less than one alkenyl group in the molecular chain, the curing reaction between the curing agent (A) and the polymer (B) is hardly inhibited and poor curing is unlikely to occur. Other functional groups may be included to some extent as long as they hardly inhibit the curing reaction between the curing agent (A) and the polymer (B).

  The amount of the plasticizer (F) added is preferably 5 parts by weight or more and 150 parts by weight or less, more preferably 10 parts by weight or more and 120 parts by weight or less, and still more preferably 20 parts per 100 parts by weight of the polymer (B). It is not less than 100 parts by weight. If the amount is less than 5 parts by weight, it may be difficult to exhibit the effect of suppressing compression residual strain and flexibility. If the amount exceeds 150 parts by weight, the mechanical strength of the modified silicone resin foam tends to be insufficient, or the expansion ratio tends to decrease. is there. The manufacturing method of a plasticizer (F) is not specifically limited, A well-known manufacturing method can be applied, and also a commercially available compound may be used.

  The curing agent (A) having at least two hydrosilyl groups in the molecular chain (hereinafter sometimes simply referred to as “curing agent (A)”) is at least 2, preferably 3 or more in the molecular chain. It has a hydrosilyl group. The upper limit of the number of hydrosilyl groups is preferably 100, more preferably 70, and even more preferably 50. Since the hydrosilyl group is thus contained in the molecular chain, each hydrosilyl group has at least one alkenyl group in the molecular chain, and a polymer in which the repeating unit constituting the main chain is an oxyalkylene unit ( It cures by reacting with the alkenyl group present in the molecular chain of B). When the number of the hydrosilyl groups is less than 2, the curing rate when the liquid resin composition of the present invention is cured by a hydrosilylation reaction is slowed, resulting in poor curing. When the number of hydrosilyl groups exceeds 100, the stability of the curing agent (A), that is, the stability of the liquid resin composition may be deteriorated, and a large amount of hydrosilyl groups are foamed even after curing. It tends to remain in the body and may cause compressive residual strain, increased hardness during heat curing, and cracks.

In addition, having one hydrosilyl group means having one SiH bond, and in the case of SiH ₂ , it has two hydrosilyl groups, but the number of H bonded to one Si is 1 It is preferable from the standpoint of flexibility, since the curability is better.

  The upper limit of the number average molecular weight of the curing agent (A) is preferably 30000, more preferably 20000, and further preferably 15000, from the viewpoints of dispersibility and workability. In consideration of the reactivity and compatibility with the polymer (B), the number average molecular weight is particularly preferably from 300 to 10,000.

  The structure of the curing agent (A) is not particularly limited as long as it has at least two hydrosilyl groups in the molecular chain. For example, a polysiloxane curing agent described in International Publication No. 2008/117734, etc. Can be illustrated. In particular, from the viewpoint of availability, reactivity, and the like, polymethylhydrogensiloxane (methylhydrogensilicone oil), methylhydrogensiloxane and dimethylsiloxane, diphenylsiloxane, methylphenylsiloxane copolymer, and these Of these, a modified product of styrene or α-methylstyrene is preferably used.

  Polymer (B) having at least one alkenyl group in the molecular chain, and the repeating unit constituting the main chain comprising an oxyalkylene-based unit (hereinafter sometimes simply referred to as “polymer (B)”) Is a component that is cured by a hydrosilylation reaction with the curing agent (A), and has at least one alkenyl group in the molecular chain. Therefore, the hydrosilylation reaction takes place to become a polymer and is cured. The number of alkenyl groups contained in the polymer (B) is at least one from the viewpoint of hydrosilylation reaction with the curing agent (A). From the viewpoint of curability and flexibility, both ends of the molecular chain are required. Preferably an alkenyl group is present.

  The structure of the polymer (B) may be linear or branched, but the linear structure is preferable from the viewpoint of flexibility. Here, the term “linear” means that the molecular structure is linear or may be branched to some extent, but is linear if the branching is less than the molecular weight of the main chain.

  As for the molecular weight of the polymer (B), the number average molecular weight (Mn) is preferably 15000 or more from the viewpoint of the balance of flexibility / tactile sensation and reactivity. More preferably, it is 17000 or more. Although there is no limitation in particular in an upper limit, 50000 or less are preferable, 45000 or less are more preferable, and 40000 or less are more preferable.

The polymer (B) is preferably produced by polymerizing a compound having two or more active hydrogens as a starting material for forming the main chain because the repeating unit constituting the main chain is an oxyalkylene-based unit. . For example, it is produced by polymerizing C ₂ -C ₄ alkylene oxide using ethylene glycol, propylene glycol, bisphenol compound, glycerin, trimethylolpropane, pentaerythritol and the like.

  Specific examples of the main chain include polyethylene oxide, polypropylene oxide, polybutylene oxide; two or more random or block copolymers selected from ethylene oxide, propylene oxide, and butylene oxide, and the like. It is preferable to introduce an alkenyl group at at least one terminal. From the viewpoints of flexibility and touch, it is more preferable that the repeating unit of the main chain is polypropylene oxide.

  The content of the curing agent (A) and the polymer (B) depends on the number of hydrosilyl groups in the curing agent (A) and the number of alkenyl groups in the polymer (B). From the viewpoint, the curing agent (A) / polymer (B) (mol / mol) is preferably 3/4 or more, more preferably 4/5 or more, and even more preferably 1 or more.

  Furthermore, it is preferable that the content of the hydrosilyl group in the curing agent (A) is 0.1 mol or more and 50 mol or less per mol of the alkenyl group in the polymer (B).

  The hydrosilylation catalyst (C) is not particularly limited as long as it can be used as a hydrosilylation catalyst, and any catalyst can be used. Specific examples of the hydrosilylation catalyst (C) include those described in International Publication No. 2008/117734, such as platinum-olefin complexes and platinum-vinylsiloxane complexes.

The content of the hydrosilylation catalyst (C) is preferably 10 ^-8 mol or more and 10 ^-1 mol or less, more preferably 10 ^-6 mol or more and 10 ^-2 mol or less, with respect to 1 mol of the alkenyl group of the polymer (B). preferable. If the content is less than 10 ⁻⁸ mol, curing may not proceed sufficiently. On the other hand, when it is more than 10 ⁻¹ mol, it may be difficult to control the curing of the liquid resin composition, or the obtained modified silicone resin foam may be colored.

  In the present invention, it is preferable to use an active hydrogen group-containing compound having no alkenyl group in the molecular chain as the foaming agent (D).

  Examples of the active hydrogen-containing compound having no alkenyl group in the molecular chain include alcohols, carboxylic acids, compounds having a phenolic hydroxyl group, and water. Further specific examples include water;

Methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, tert-butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, Monohydric alcohols such as ethylene glycol monophenyl ether;

Ethylene glycol, propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, diethylene glycol, triethylene glycol, neopentyl glycol, 1,6-hexamethylene glycol, 1,9-nona Polyhydric alcohols such as methylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, sucrose;

Polyether polyols including polypropylene glycol, polyethylene glycol, copolymers thereof, polytetramethylene glycol, sorbitol, sucrose, tetraethylenediamine, ethylenediamine, etc. containing one or more hydroxyl groups in one molecule ;

Polyester polyols such as adipate polyols, polycaprolactone polyols, polycarbonate polyols;

Epoxy modified polyols; polyether ester polyols; phenolic polyols such as benzylic ether type phenol polyols; fluorine polyols such as Lumiflon (Asahi Glass Co., Ltd.); hydrogenated polybutadiene polyols; castor oil-based polyols; halogen-containing flame-retardant polyols; Flame retardant polyol;

An acrylic resin having a hydroxyl group that can be obtained by copolymerization of a hydroxyl group-containing vinyl monomer with acrylic acid, methacrylic acid, or a derivative thereof; other resins having a hydroxyl group such as alkyd resins and epoxy resins;
Alcohols such as;

Carboxylic acids such as monovalent saturated carboxylic acids such as acetic acid and propionic acid; compounds having phenolic hydroxyl groups such as phenol, cresol, xylenol, resorcin, catechol, pyrogallol, bisphenol A, bisphenol B, bisphenol S, and phenol resin;
Etc.

  Among these active hydrogen group-containing compounds that do not contain an alkenyl group in the molecular chain, primary saturated hydrocarbon alcohols such as methanol, ethanol, n-propanol and n-butanol, polyethylene, etc. from the viewpoint of reactivity and handling It is preferably at least one selected from the group consisting of polyether polyols such as glycol and water, and from the viewpoint of flexibility, a compound in which oxygen is directly bonded to carbon or water is preferable. In particular, any of water, ethanol, and polyethylene glycol is preferable.

  In the present invention, when an active hydrogen group-containing compound that does not contain an alkenyl group in the molecular chain is used as the foaming agent (D), the number average molecular weight of the active hydrogen group-containing compound that does not contain an alkenyl group in the molecular chain is large. When it becomes, since reactivity will fall and the desired foaming ratio will not be obtained, 1000 or less are preferable and 500 or less are more preferable.

  Moreover, since the hydroxyl equivalent of an active hydrogen group-containing compound that does not contain an alkenyl group in the molecular chain tends to increase the volume of the active hydrogen group-containing compound to be added and increase the expansion ratio when the hydroxyl equivalent is reduced. When increasing the expansion ratio, it is preferably 1.0 mmol / g or more, and more preferably 5.0 mmol / g or more from the viewpoint of reactivity.

  In the present invention, a foaming agent other than the active hydrogen group-containing compound having no alkenyl group in the molecular chain may be used in combination as the foaming agent (D). As a foaming agent other than an active hydrogen group-containing compound having no alkenyl group in the molecular chain, for example, physical foaming of volatile liquid or gas, which is usually used for organic foams such as polyurethane, phenol, polystyrene, polyolefin, etc. And chemical foaming agents that generate gas by thermal decomposition or chemical reaction.

  The physical foaming agent is not particularly limited as long as it does not inhibit the hydrosilylation reaction, but from the viewpoint of foamability, workability and safety, the physical foaming agent preferably has a boiling point of 100 ° C. or lower. 50 ° C. or lower is more preferable. Specific examples include organic compounds such as hydrocarbons, chlorofluorocarbons, alkyl chlorides and ethers, and inorganic compounds such as carbon dioxide, nitrogen and air. From the viewpoint of environmental compatibility, hydrocarbons, ethers, carbon dioxide and nitrogen. It is preferable to use a compound selected from air.

  Hydrocarbons include methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3- Examples thereof include dimethyl butane crobutane, cyclopentane, and cyclohexane. Examples of ethers include dimethyl ether, diethyl ether, ethyl methyl ether, dipropyl ether, diisopropyl ether, butyl methyl ether, butyl ethyl ether, tert-butyl methyl ether, tert-butyl ethyl ether, 1,1-dimethylpropyl methyl. Examples include ether.

  In addition, when performing mechanical stirring in the air at the time of foam manufacture, air bubbles may be formed by the air entrained with the stirring, which is also considered to be one of physical foaming agents. However, when these physical foaming agents are used, there are concerns about changes in physical properties after foam molding due to residuals, etc., so that after foam production, by heating and curing at a temperature equal to or higher than the boiling point of the physical foaming agent used. It is preferable to remove the residual foaming agent.

The chemical foaming agent is not particularly limited as long as it does not inhibit the hydrosilylation reaction, and examples thereof include inorganic chemical foaming agents such as NaHCO ₃ and organic chemical foaming agents.

  In the present invention, as a foaming aid, a compound (E) having at least one alkenyl group and at least one hydroxyl group in the molecular chain (hereinafter sometimes simply referred to as “compound (E)”). It is preferable to add it because a low-density modified silicone resin foam tends to be obtained. The alkenyl group in the compound (E) delays the crosslinking reaction by causing an addition reaction to the hydrosilyl group in the curing agent (A) by competing with the alkenyl group in the polymer (B), and the molecule It is considered that the density of the modified silicone resin foam can be reduced by generating hydrogen as a result of the hydroxyl group in the ring undergoing a condensation reaction with the hydrosilyl group in the curing agent (A). However, when a cross-linked structure via compound (E) is introduced by the above addition reaction and condensation reaction, while the expansion ratio is increased, there are cases where problems such as a decrease in mechanical strength and an increase in hardness may occur. By adding the agent (F) and further by setting the number average molecular weight (Mn) of the polymer (B) to 15000 or more, there is a tendency that it is easy to achieve both low density and flexibility. Although it is possible to improve the magnification by adding a large amount of a foaming agent (D) which is an active hydrogen group-containing compound other than the compound (E), or by adding other foaming agents, the obtained modified silicone resin foam From the viewpoint of hardness and physical property balance, it is preferable to use the compound (E) of the present invention.

  As a compound (E), the following can be illustrated typically.

Monohydric alcohols such as ethylene glycol monoallyl ether and glyceryl diallyl ether;
Polyhydric alcohols such as glyceryl monoallyl ether;
Polymer one-terminal allyl ether, vinyl ether or (meth) acrylic acid ester of a polymer in which the repeating unit constituting the main chain such as polypropylene glycol, polyethylene glycol and copolymers thereof is an oxyalkylene-based unit;

Polyethermethylene glycol, sorbitol, sucrose, tetraethylenediamine, ethylenediamine, etc. as an initiator, polyether polyol one-end allyl ether, vinyl ether or (meth) acrylic acid ester such as those containing 3 or more hydroxyl groups in one molecule ;

One terminal allyl ether, vinyl ether or (meth) acrylic acid ester of polyester polyol such as adipate polyol, polycaprolactone polyol, polycarbonate polyol;
Polybutadiene polyol; castor oil-based unsaturated group-containing polyol;

2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxyethyl vinyl ether, N-methylol (meth) acrylamide, “Aronix 5700” manufactured by Toagosei Co., Ltd., 4-hydroxystyrene, “HE-10”, “HE-20”, “HP-10”, and “HP-20” manufactured by Nippon Shokubai Chemical Industry Co., Ltd. [all of which are acrylic ester oligomers having a hydroxyl group at the terminal], Nippon Oil ( As the Blemmer series manufactured by Co., Ltd., PP series [polypropylene glycol methacrylate], Blemmer PE series [polyethylene glycol monomethacrylate], Blemmer PEP series [polyethylene glycol polypropylene glycol methacrylate], Blemmer AP- 00 [polypropylene glycol monoacrylate], Blemmer AE-350 [polyethylene glycol monoacrylate], Blemmer NKH-5050 [polypropylene glycol polytrimethylene monoacrylate], and Blemmer GLM [glycerol monomethacrylate], hydroxyl group-containing vinyl compounds and ε -Hydroxyl group-containing vinyl monomers such as ε-caprolactone modified hydroxyalkyl vinyl monomers obtained by reaction with caprolactone;
Alcohols such as;
Etc.

  Among these compounds, from the viewpoint of reactivity and handleability, polymer one-terminal allyl ether, vinyl ether or (meth) acrylic acid ester in which the repeating unit constituting the main chain is an oxyalkylene-based unit is preferable, and high doubling is achieved. From the viewpoint of efficiency in contributing to the above, polypropylene glycol, polyethylene glycol, and one-terminal allyl ethers of these copolymers are more preferable, and one-terminal allyl ether of polyethylene glycol is particularly preferable.

  The ratio of the compound (E) and the polymer (B) is such that the compound (E) / polymer (B) (mol / mol) is 6 or more from the viewpoint that a low density modified silicone resin foam is obtained. Preferably, it is 7 or more, more preferably 8 or more.

  In the present invention, the blending ratio of the curing agent (A), the polymer (B), the foaming agent (D), and the compound (E) is appropriately selected depending on the structure of each compound, the target foaming ratio, and the target physical properties. The number of moles of hydrosilyl groups in the curing agent (A): x, the number of moles of alkenyl groups in the polymer (B) and the compound (E): y, foaming The ratio of the number of moles of hydroxyl groups in the agent (D) and the compound (E) to the sum of z is preferably x / (y + z) = 1/10 to 50/1, and x / (y + z) = 1/5 to 30/1 is more preferable, and x / (y + z) is more preferably 1/2 to 20/1. If x / (y + z) exceeds 50/1, the crosslinking density may be low, and sufficient mechanical strength may not be obtained. If x / (y + z) is less than 1/10, sufficient foaming, Curing may not occur.

  The ratio of the number of moles of alkenyl groups of the polymer (B) and the compound (E): y and the number of moles of hydroxyl groups of the foaming agent (D) and the compound (E): z is not particularly limited. Can be appropriately selected depending on the foaming ratio, the target physical properties, the skeleton of the curing agent (A), and the type of the foaming agent (D). In general, y: z = 100: 1 to 1: 100 is preferable, and y: z = 10: 1 to 1:20 is more preferable.

  As long as the effects of the present invention are not impaired, the modified silicone resin foam of the present invention may be added with a light-resistant stabilizer, an ultraviolet absorber, a storage stabilizer, a cell regulator, a surfactant and the like as necessary. good.

  Examples of the light-resistant stabilizer include hindered phenol antioxidants and hindered amine light stabilizers that do not contain sulfur atoms, phosphorus atoms, primary amines, and secondary amines. Here, the light-resistant stabilizer is a function that absorbs light having a wavelength in the ultraviolet region and suppresses the generation of radicals, or a function that captures radicals generated by light absorption and converts them into heat energy to render them harmless. And a compound that enhances stability to light.

  The ultraviolet absorber is not particularly limited, and examples thereof include benzoxazine ultraviolet absorbers, benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, and triazine ultraviolet absorbers. Here, the ultraviolet absorber is a compound having a function of absorbing light having a wavelength in the ultraviolet region and suppressing generation of radicals.

  The addition amount of the light resistance stabilizer and the ultraviolet absorber is preferably 0.01 parts by weight or more and 5 parts by weight or less, more preferably 0.1 parts by weight or more and 3 parts by weight or less with respect to 100 parts by weight of the polymer (B). Part by weight or less is more preferable, and 0.3 part by weight or more and 2.0 parts by weight or less is particularly preferable. When the addition amount of the light-resistant stabilizer and the ultraviolet absorber is within this range, the effect of suppressing the increase in surface tack over time tends to be easily obtained.

  As the storage stability improver, any conventional stabilizer known as a storage stabilizer for the curing agent (A) can be used as long as it achieves the intended purpose.

  Preferred examples of such storage stability improvers include, for example, compounds containing aliphatic unsaturated bonds, organophosphorus compounds, organosulfur compounds, nitrogen-containing compounds, tin compounds, and organic peroxides. And at least one selected from these groups can be used. Specific examples include benzothiazole, thiazole, dimethyl malate, dimethyl acetylenedicarboxylate, 2-pentenenitrile, 2,3-dichloropropene, quinoline, and the like, and at least one selected from these groups is used. However, it is not limited to these. Among these, thiazole, benzothiazole, and dimethyl malate are particularly preferable from the viewpoint of both pot life and fast curability.

The amount of the storage stability improver used can be selected almost arbitrarily as long as it is uniformly dispersed in the curing agent (A) and the polymer (B). In the curing agent (A), 1 mol of SiH groups is used. On the other hand, it is preferably used in the range of 10 ⁻⁶ mol or more and 10 ⁻¹ mol or less. When the amount used is less than 10 ^-6 mol, the storage stability of the curing agent (A) may not be sufficiently improved, and when it exceeds 10 ^-1 mol, the curability may be insufficient.

  If necessary, a foam regulator may be added to the modified silicone resin foam of the present invention. There are no particular limitations on the type of cell regulator, and commonly used, for example, inorganic solid powders such as talc, calcium carbonate, magnesium oxide, titanium oxide, zinc oxide, carbon black, silica, polyether modified silicone oil, etc. Silicone oil-based compounds, fluorine-based compounds, and the like, and at least one selected from these groups can be used. The amount of the foam regulator used is 0.1 to 100 parts by weight when the total amount of the curing agent (A), polymer (B), hydrosilylation catalyst (C) and compound (E) is 100 parts by weight. Part by weight or less is preferable, and 0.5 part by weight or more and 50 parts by weight or less is more preferable.

  Also, the compatibility of the foamable liquid resin composition comprising the curing agent (A), the polymer (B), the hydrosilylation catalyst (C), the foaming agent (D), the compound (E), and the plasticizer (F). In order to improve the surface active agent, a surfactant may be added. Specific examples of surfactants include alkyl sulfates such as sodium lauryl sulfate, polyoxyethylene alkyl ether sulfates such as sodium polyoxyethylene lauryl ether sulfate, polyoxyethylene alkyl ether acetate, lauryl trimethyl ammonium chloride, alkoxy chloride Propyltrimethylammonium chloride, dialkyldimethylammonium chloride, benzalkonium chloride solution, alkyldimethylaminoacetic acid betaine, alkyldimethylamine oxide, alkylcarboxymethylhydroxyethyl imidazolinium betaine, alkylamidopropyl betaine, glycerin fatty acid ester, propylene glycol fatty acid ester, Nonionic surfactants such as sorbitan fatty acid esters are listed, and one or more are used. It can be.

In particular, for the purpose of improving the compatibility of the curing agent (A), a silicone surfactant such as a polyoxyalkylene-polydimethylsiloxane block copolymer can be added. The polyoxyalkylene-polydimethylsiloxane block copolymer is not particularly limited. For example, in addition to an AB type diblock body, an ABA type triblock body, an (AB) _n type multiblock body, a branched type, A pendant type, a star type, etc. are mentioned. In addition, specific structures of polyoxyalkylene include polyoxyethylene, polyoxypropylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer, and the terminal structure is also OH. Examples thereof include a base end, an ether end such as methoxy and t-butoxy, and a reactive allyl group end.

  In addition, if necessary, filler, radical inhibitor, adhesion improver, flame retardant, foam stabilizer, acid or basic compound, storage stability improver, ozone degradation inhibitor, thickener, coupling agent, Conductivity-imparting agent, antistatic agent, radiation blocking agent, nucleating agent, phosphorus peroxide decomposing agent, lubricant, pigment, metal deactivator, physical property modifier, etc., in a range that does not impair the purpose and effect of the present invention Can be added.

  The production method of the modified silicone resin foam is not particularly limited. For example, as the modified silicone resin, a curing agent (A), a polymer (B), a hydrosilylation catalyst (C), a foaming agent (D), a compound ( E) The foamable liquid resin composition comprising the plasticizer (F) can be used as follows.

  The polymer (B), hydrosilylation catalyst (C), blowing agent (D), compound (E), and plasticizer (F) are mixed in advance, the curing agent (A) is added, and the mixture is stirred. After adjusting and pouring into a formwork or hanging on a substrate on a belt conveyor, the foamable liquid resin composition is foamed under appropriate conditions and then cured, or by foaming simultaneously with curing, The modified silicone resin foam of the present invention is obtained.

  The obtained modified silicone resin foam is preferably subjected to heat curing because it tends to reduce compressive residual strain. The heat curing conditions are not particularly limited, but it is preferable to perform the heat curing under the conditions of 20 ° C. or more and 200 ° C. or less and 10 minutes or more and 72 hours or less because the compression residual strain is reduced. In the modified silicone resin foam, the hardness generally increases due to heat curing and the tactile sensation may deteriorate, but the modified silicone resin foam of the present invention contains a plasticizer (F). Thus, an excessive increase in hardness and deterioration in tactile sensation are suppressed, and compressive residual strain can be reduced while maintaining flexibility and tactile sensation even after heat curing.

  The compression residual strain of the modified silicone resin foam of the present invention is preferably 8% or less, more preferably 5% or less. A small compressive residual strain means that, for example, when used as a pillow, the strain at the time of use is small and an excellent restoring property is exhibited.

  The compressive residual strain is measured in accordance with JIS K 6400-4. The original thickness of the foam after compressing 75% of the foam under the conditions of 60 ° C. and 24 hours, then releasing at room temperature and recovering for 30 minutes. The rate of decrease with respect to the thickness.

  The modified silicone resin foam of the present invention has a 40% compression hardness measured in accordance with JIS K 6400-2, preferably 30 N or less, more preferably 25 N or less. When the hardness at 40% compression exceeds 30 N, the foam tends to be too hard and the tactile sensation tends to deteriorate. The lower limit of the hardness at the time of 40% compression is not particularly limited, but if it is too low, the foam becomes too soft and the sinking is large and bottoming occurs.

The modified silicone resin foam of the present invention preferably has a density of 150 kg / m ³ or less. More preferably, it is 140 kg / m < ³ > or less, More preferably, it is 130 kg / m < ³ > or less. When the density is within the above range, for example, when it is commercialized as a bedding or a cushion, it is assumed that it is comparatively light and easy to carry on a daily basis. The lower limit is not particularly limited, but is preferably 30 kg / m ³ or more, more preferably 50 kg / m ³ or more, and particularly preferably 70 kg / m ³ or more. If the density is too small, it may bottom out due to compression when used as bedding or a cushion.

  The modified silicone resin foam of the present invention obtained as described above does not contain a substance that may cause harmful by-products, has high flexibility and good tactile sensation, and has a small compressive residual strain. Therefore, it can be suitably used as bedding such as pillows and mattresses and various cushion materials. Among them, it is preferable to use as bedding.

  When the modified silicone resin foam is used as a bedding, it can be used as it is, or a skin layer formed at the time of foam molding is excised, cut into an appropriate shape, or punched out. Alternatively, as long as it is in a range that makes use of the features that are flexible and have good tactile sensation, it is integrally formed with raw materials such as unfoamed plastics, modified silicone resin foams with different expansion ratios, films, cloths, non-woven fabrics, paper, and fibers. The surface of the modified silicone resin foam may be used in combination with a woven or non-woven fabric made of cotton, acrylic fiber, hair, polyester fiber or the like by pasting or stitching.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The measurement and evaluation in the examples and comparative examples were performed under the following conditions and methods. Unless otherwise noted, the parts and percentages in the examples and comparative examples are based on weight.

<Foam density>
A rectangular parallelepiped of about 30 mm square was cut out from the modified silicone resin foam, and the volume (m ³ ) was calculated by measuring the size of three sides, and was calculated by dividing it from the measured weight (kg).

<Tactile sense>
The tactile sensation when the foam was compressed with palm was evaluated according to the following criteria.
○: Good tactile sensation ... Feels like the palm is wrapped while compressing because it is soft and soft to rebound when compressed with the palm.
X: Bad tactile sensation ... Hard or bounced when compressed with palm, feels like resistance.
[Delta]: Tactile feeling is neither good nor bad

<Hardness at 40% compression>
Based on JIS K 6400-2 A method, the hardness at the time of 40% compression was measured.

<Compressive residual strain>
According to JIS K 6400-4 C method, it implemented by 60 degreeC, 24 hours, and 75% compression.

<Compound used>
In the examples and comparative examples, the compounds shown in Table 1 were used.

(Synthesis of plasticizer 3)
An oxypropylene polymer glycol having a number average molecular weight of 3000 was obtained by a polymerization method using caustic alkali. Propylene oxide was polymerized using a double metal cyanide complex (zinc hexacyanocobaltate) using the obtained oxypropylene polymer glycol as an initiator to obtain a polymer having a number average molecular weight of 20,000.

(Examples 1-5)
For 100 parts of polymer (B), 0.13 parts of catalyst (C), 12.3 parts of foaming agent (D), 20 parts of compound (E), 2 parts of surfactant, and plastic The number of parts shown in Table 2 was added and mixed well, and then 16.1 parts of curing agent (A) was added and mixed quickly. This mixture was poured into a mold and cured by heating in an oven set at 50 ° C. for 60 minutes to obtain a modified silicone resin foam. Thereafter, heat curing was performed in an oven set at 100 ° C. for 5 hours. The evaluation results after heat curing are shown in Table 2.

(Comparative Example 1)
A modified silicone resin foam was obtained in the same manner as in Example 1 except that no plasticizer was added. Thereafter, heat curing was performed in an oven set at 100 ° C. for 5 hours. The evaluation results after heat curing are shown in Table 2.

(Comparative Example 2)
To 100 parts of polymer (B), 0.029 parts of catalyst (C), 7.7 parts of foaming agent (D) and 2 parts of surfactant are added and mixed thoroughly. 12 parts of (A) was added and mixed quickly. This mixture was poured into a mold and cured by heating in an oven set at 50 ° C. for 60 minutes to obtain a modified silicone resin foam. Thereafter, heat curing was performed in an oven set at 100 ° C. for 5 hours. The evaluation results after heat curing are shown in Table 2.

(Reference Example 1)
In Comparative Example 1, Table 2 shows the evaluation results when heat curing is not performed for 5 hours in an oven set at 100 ° C.

(Reference Example 2)
In Comparative Example 2, Table 2 shows the evaluation results when heat curing is not performed for 5 hours in an oven set at 100 ° C.

  From Comparative Examples 1 and 2, it can be seen that the density is decreased by adding the compound (D). However, in Comparative Examples 1 and 2, when heat curing is performed, the compressive residual strain becomes a small value, but an increase in hardness is seen and the tactile sensation is also poor. About these comparative examples 1 and 2, although the reference examples 1 and 2 have shown the evaluation result when not performing heat curing, when not performing heat curing, 40% compression hardness is 30 N or less and a flexible property. However, it can be seen that the compressive residual strain is large and easily distorted.

  In contrast to the above, in Examples containing a plasticizer with a number average molecular weight of 3000 to 20000, a flexible property with a 40% compression hardness of 25 N or less is obtained even after heat curing, and 5% It can be seen that the following low compression residual strain is obtained.

Claims (8)

  Curing agent (A) having at least two hydrosilyl groups in the molecular chain, polymer having at least one alkenyl group in the molecular chain, and a repeating unit constituting the main chain consisting of oxyalkylene units (B ), Hydrosilylation catalyst (C), blowing agent (D), the repeating unit constituting the main chain consists of oxyalkylene units, and has an average of less than one alkenyl group in the molecular chain, and has a number average molecular weight A modified silicone resin foam obtained by curing a foamable liquid resin composition comprising a plasticizer (F) having an A of 1000 or more.   The modified silicone resin according to claim 1, wherein the polymer (B) having at least one alkenyl group in the molecular chain and the repeating unit constituting the main chain comprising an oxyalkylene unit has a number average molecular weight of 15000 or more. Foam.   The modified silicone resin according to claim 1 or 2, wherein the foaming agent (D) is an active hydrogen compound having no alkenyl group in the molecular chain, a number average molecular weight of 1000 or less, and a hydroxyl group equivalent of 1.0 mmol / g or more. Foam.   A foamable liquid resin composition comprising a compound (E) having at least one alkenyl group and at least one hydroxyl group in a molecular chain as a foaming aid is cured. The modified silicone resin foam according to claim 1.   The modified silicone resin foam according to any one of claims 1 to 4, which has a compression residual strain of 8% or less when compressed 75% under conditions of 60 ° C and 24 hours. The modified silicone resin foam according to any one of claims 1 to 5, having a density of 150 kg / m ³ or less.   The modified silicone resin foam according to any one of claims 1 to 6, wherein the hardness at 40% compression is 30 N or less.   A bedding comprising the modified silicone resin foam according to any one of claims 1 to 7.