JPS6137098B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a foamed resin composite molded article whose surface is partially or entirely covered with a layer of cured unsaturated polyester resin.

Composites consisting of a foamed resin molded product and at least a portion of its surface made of unsaturated polyester resin, or unsaturated polyester resin (so-called FRP) containing fibers, fillers, application materials, etc., have excellent strength, lightness, and heat insulation properties. It is useful because of the following properties. As foamed resins used in such composites, those made of hard urethane resins and hard vinyl chloride resins are already known. However, these foamed resins have the following drawbacks.

Rigid urethane foam has a brittle property due to its strength, and when used as a foam core material, it may be destroyed by repeated loads. Moreover, molded products with good dimensional accuracy cannot be obtained industrially. Furthermore, a foam core material with good dimensional accuracy can be obtained by cutting out a slab-shaped foam molded product, joining it, etc. However, such a method has a low yield, and joining work increases the number of manufacturing steps, which inevitably increases the cost. I have no choice but to get high.

Rigid vinyl chloride foams are difficult to manufacture into molded articles. Therefore, a foam core material with good dimensional accuracy can be obtained by cutting out, joining, etc. from a slab-shaped foam molded product. However, the yield is low, and the joining work increases the number of manufacturing steps, resulting in high costs.

Foamed polystyrene is a typical foamed resin, which is cheaper than the foamed resins mentioned above and can be easily molded into molded products. Or FRP cannot be formed. The reason for this is that the expanded styrene resin dissolves in the polymerizable monomers (mainly styrene, vinyltoluene, methyl methacrylate, etc.) contained in the unsaturated polyester resin before curing. In order to prevent such dissolution, the only way is to mold expanded polystyrene and unsaturated polyester resin or their FRP separately and then combine them with adhesive.
This manufacturing method requires extra adhesive and requires a large number of manufacturing steps, resulting in high costs. It is also extremely difficult to foam styrene resin between two plates with an unsaturated polyester resin or FRP molded product interposed therebetween. Proposals have been made to cure unsaturated polyester resin or form FRP with expanded styrene resin containing polyethylene, but polyethylene inhibits adhesion with unsaturated polyester resin, and the strength, especially rigidity, decreases due to the softening caused by polyethylene. do.

The present invention solves these problems.

That is, the present invention provides a foamed resin composite in which a part or the entire surface of a foamed styrene resin molded product is coated with a cured unsaturated polyester resin, in which the foamed styrene resin molded product contains a styrene resin and a cured unsaturated polyester resin. In an expandable styrenic resin composition containing a blowing agent, the styrenic resin has the general formula () -SiYnR _3-o () (where R is inert) in the molecule. is a monovalent organic group,
Y is a hydrolyzable group, and n is an integer of 1-3. ), and the expandable styrenic resin composition optionally contains an organic silane compound having at least two or more hydrolyzable groups. The present invention relates to a foamed resin composite made of a foamed molded product.

The above-mentioned styrene resin is a polymer or copolymer of a styrene monomer, or a copolymer of a styrene monomer and another monomer. Here, styrenic monomers include substituted styrenes such as styrene, α-methylstyrene, vinyltoluene, and chlorostyrene; other monomers include divinylbenzene, vinyl cyanide compounds such as acrylonitrile, methyl acrylate, ethyl acrylate,
Acrylic acid esters such as butyl acrylate and hydroxyethyl acrylate, methacrylic acid esters such as methyl methacrylate, butyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, unsaturated carboxylic acid anhydrides such as maleic anhydride, and their mono- or dialkyl esters, etc. Or two or more types are used. Furthermore, in the present invention, the styrenic resin preferably contains 50% by weight or more of styrene or the various substituted styrenes mentioned above in its constituent components from the viewpoint of expansion ratio, fusion of molded articles, surface appearance, and manufacturing cycle.

This styrenic resin further has a group represented by the general formula () chemically bonded in its molecule. The group represented by this general formula () is 0.03 to 20% by weight, preferably 0.05 to 10% by weight in the styrene resin.
It is preferable that it is contained in a proportion by weight since it has a well-balanced foaming performance, moldability, heat resistance, and poor solubility in unsaturated polyester resins.

In the general formula (), the group Y is a hydrolyzable group such as an alkoxy group having 1 to 6 carbon atoms, an acyloxy group having 1 to 6 carbon atoms, an oximo group having 1 to 14 carbon atoms, etc., such as a methoxy group, an ethoxy group, etc. group, alkoxy group such as butoxy group, formyloxy group,
Acyloxy group such as acetoxy group or propyleneoxy group, -ON=C( _CH3 ) ₂ , -ON=C
(CH ₃ )C ₂ H ₅ , -ON=C(C ₆ H ₅ ) _2, a group that generates a hydroxyl group by hydrolysis, such as an oximo group, -
alkylamino or _arylamino groups such _{as NHCH3} , _-NHC2H5 and NH( _C6H5 ). When n is 2 or 3, the substituents Y may be the same or different. The group R is an inert monovalent organic group, preferably a hydrocarbon group having 1 to 18 carbon atoms, such as an alkyl group such as methyl, ethyl, propyl, butyl, tetradecyl, octadecyl group, phenyl group, benzyl group, etc. group, aryl group such as tolyl group, aracyl group, alkaryl group, etc.

The following methods can be used to introduce a group represented by the general formula () into a styrene resin.

(1) When polymerizing vinyl monomers such as styrenic monomers or styrene monomers and _other monomers, the general formula () A group having a possible double bond, where Y, R and n are represented by the general formula ()
It is similar to ), where the polymerization method includes suspension polymerization,
Bulk polymerization, solution polymerization, etc. are optional.

The above group X is a group having a copolymerizable double bond, for example, a vinyl group, an allyl group, an alkenyl group such as a butenyl group, a cyclohexenyl group,
Cycloalkenyl groups such as cyclopentadienyl group and cyclohexadienyl group, unsaturated acyloxyalkyl groups such as γ-methacryloxypropyl group, unsaturated acyloxyalkoxy groups such as γ-methacryloxyethylpropyl ether group, CH ₂
=C( _CH3 )COO( _CH2 ) _{2OCH2CH (} OH)
_CH2O ( _CH2 ) _3- etc. Among these, the most preferred are unsaturated acyloxyalkyl groups such as γ-methacryloxypropyl group or unsaturated acyloxyalkoxy groups such as γ-methacryloxyethylpropyl ether group.

A particularly preferable compound as a compound represented by the above general formula () is the general formula () X′SiY′ ₃ () (wherein, (Y' is an alkyl group or an aryl group.) Among these, the most preferred is γ-methacryloxypropyltrimethoxysilane.

In addition, suitable polymerization initiators include benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-di(peroxybenzoate)hexyne-3,1,3-bis (tert-butylperoxyisopropyl)benzene, lauroyl peroxide, tert-butyl peracetate, 2,5-dimethyl-2,5-di(tert-butylperoxy)
Hexyne-3,2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and tertiary
There are organic peroxides such as butyl perbenzoate, methyl ethyl ketone peroxide, and methyl cyclohexanone peroxide, and azo compounds such as azobis-isoptilonitrile and dimethyl azodiisobutyrate, and one or more of these can be used. The amount used is determined by the type of vinyl monomer and organic silane compound and the desired molecular weight of the obtained polymer, but preferably 0.1 to 4.0 with respect to the vinyl monomer and organic silane compound.
% by weight used.

In the case of suspension polymerization in the above, the polymerization is carried out in an aqueous medium, and in this case, a sparingly soluble phosphate, a water-soluble polymeric protective colloid, etc. can be added to the polymerization system as a dispersant. Examples of sparingly soluble phosphates include tricalcium phosphate and magnesium phosphate. Examples of polymeric protective colloids include polyvinyl alcohol, water-soluble cellulose derivatives such as alkyl cellulose, hydroxyalkyl cellulose, and carboxyalkyl cellulose, and sodium polyacrylate. It is preferable that the sparingly soluble phosphate is used in an amount of 0.01% by weight or more, and the water-soluble polymer protective colloid is used in an amount of 1 to 0.001% by weight based on the total amount of substances present in the polymerization system. In addition, anionic surfactants and water-soluble inorganic salts can be added to the polymerization system.

In the above, xylene,
Organic solvents such as toluene can be used.

(2) Strongly grinding and shearing the styrene resin (which does not have the group represented by the general formula () and can be produced by the method (1) above) and the compound represented by the general formula () By mechanical treatments such as kneading and cutting, the free radicals generated in the styrene resin react with the double bonds of the compound represented by the general formula (). In addition, free radicals are generated in the styrene resin, and a compound represented by the general formula () is grafted onto the free radicals.

(3) Styrenic copolymers with functional groups such as carboxyl, hydroxyl, amide, and epoxy groups (e.g., styrene-maleic anhydride, styrene-methacrylic acid, styrene-β-hydroxymethacrylate, styrene-acrylamide, etc.) Polymer) with the general formula () X″SiYnR _3-o () (where X″ is a carboxyl group, a hydroxyl group,
It is a group reactive with a functional group such as an amide group or an epoxy group, and Y, R and n are the same as in the general formula (). ) is subjected to a graft reaction.

As a compound represented by the general formula (),
For example, γ-glycidoxypropyltrimethoxysilane N-β(aminoethyl)γ-aminopropyltrimethoxysilane (H ₂ NC ₂ H ₄ NHC ₃ H ₆ Si
(OCH ₃ ) ₃ ), γ-aminopropyltriethoxysilane (H ₂ NC ₃ H ₆ Si (OC ₂ H ₅ ) ₃ ), etc.

To illustrate the reaction method, for example, styrene-
γ-glycidoxypropyltrimethoxysilane is added to a high boiling point solvent such as toluene or xylene for methacrylic acid copolymer, heated to 80°C or higher, and stirred.

(4) Polystyrene or styrene copolymer particles are suspended in water, heated while stirring, and styrene monomers, other monomers, a compound represented by the general formula (), and a polymerization catalyst are added to form a polymer. A group represented by the general formula () is introduced therein. Note that the other points are the same as in (1) above.

(5) After dissolving the styrene resin having a group represented by the general formula () obtained by the method of (1) above in a styrenic monomer, suspension polymerization, bulk polymerization,
A polymer is produced by solution polymerization or the like. The polymerization method is the same as (1) above.

The foaming agent for the above-mentioned foamable styrenic resin composition has a boiling point lower than the softening point of the styrenic resin used in combination, and does not dissolve the styrenic resin or only slightly swells the styrenic resin. Use something with properties. Examples of such blowing agents include aliphatic hydrocarbons such as propane, butane, and bentane, cyclic aliphatic hydrocarbons such as cyclobutane and cyclopentane, and halogenated hydrocarbons such as methyl chloride and dichlorodifluoromethane. can. The amount of blowing agent used is 1 to 20% by weight based on the styrene resin.

Among the above blowing agents, when propane and butane are used alone or in combination, it is preferable to use a small amount of a polystyrene or styrene copolymer solvent. Examples of such solvents include ethylene dichloride, trichloroethylene, tetrachloroethylene, benzene, toluene, xylene, ethylbenzene, and the like.

Furthermore, the organic silane compound which is a component of the present invention and is used as necessary and has a structure that becomes a hydroxyl group when hydrolyzed is expressed by the general formula () YnSiR′ _o-4 ( Here, Y is the same as in the general formula (), and R' is the same as R in the general formula () or X in the general formula (). n is an integer from 2 to 4.) It is a compound represented by the above formula, and is used in an amount of 20% by weight or less based on the styrene resin. This component supplementarily improves the heat resistance of the resulting expandable styrenic resin composition.

A method for impregnating a styrenic resin having a group represented by the general formula () with a blowing agent involves suspending particles (obtained by suspension polymerization) or pellets of the styrenic resin in an aqueous medium. Other methods include a method of press-fitting a foaming agent, a method of kneading the styrene resin and the foaming agent, and a method of immersing the styrene resin in a foaming agent (liquid). In addition, when the above styrene resin is obtained by suspension polymerization,
During the polymerization, preferably the monomer conversion rate is 50
This can be carried out by press-injecting a blowing agent at a point of at least % by weight.

The compound having a hydrolyzable double bond is simultaneously impregnated with the blowing agent, and together with the blowing agent,
It may be handled and mixed with other components, or it may be kneaded with the styrene resin or added during polymerization, and then impregnated with a blowing agent by the method described above.

Note that the foamable styrenic resin composition may contain known additives such as pigments, flame retardants, antioxidants, and antistatic agents.

The foaming of the expandable styrene resin composition is carried out by heating, reducing pressure, or the like. As the method, the foaming and molding methods of styrenic resin, which are widely used industrially, can be applied as they are. For example, if the resin is in the form of particles, it can be pre-foamed with steam and then further steam-foamed in a molding machine to obtain a molded product. Moreover, a foam can also be obtained using an extrusion foaming machine.

The expansion ratio of the above-mentioned expandable styrenic resin composition can be arbitrarily selected from a low ratio to a high ratio.

The foamed molded product obtained from the above-mentioned foamable styrenic resin composition has excellent heat resistance. The reason for this is that the group represented by the general formula () chemically bonded to the polymer or the group and the organic silane compound dispersed in the styrene resin undergo a crosslinking reaction due to heat, causing the polymer to gel. Conceivable. This crosslinking reaction hardly progresses during the normal foam molding stage. Therefore, foaming is not inhibited due to crosslinking, and the foam can be easily formed. This is one of the most important features of the above-mentioned expandable styrenic resin composition. In order to emphasize this feature, it is preferable to treat the expandable styrenic resin composition with water or steam before molding, or to steam mold it. The crosslinking reaction that proceeds in foam molded articles is temperature dependent. The crosslinking reaction proceeds gradually at temperatures below 100°C, and proceeds rapidly at temperatures above 100°C depending on the temperature. Therefore, the molded product does not require any special treatment for heat resistance and becomes heat resistant in accordance with the conditions of use. However, depending on the purpose of use, it may be preferable to subject the molded article to heat treatment (in some cases, water or steam treatment followed by heat treatment) before use. In any case, although the heat resistance of foam molded products made from the foamable styrene resin composition according to the present invention varies depending on the expansion ratio, when compared with molded products using conventional foamable polystyrene, the heat resistance It has excellent performance in Furthermore, unsaturated polyester resins are poorly soluble (particularly those that have undergone heat treatment have a high degree of solubility), so even if unsaturated polyester resin is coated on the surface of a molded product, the molded product may shrink. ,
It will not dissolve or be attacked. However, the surface of the molded product may swell or dissolve slightly, but in this case, unless the cell structure of the molded product is destroyed, the adhesive force at the composite interface will be strengthened.

The unsaturated polyester of the present invention uses unsaturated acids such as maleic anhydride, fumaric acid, and itaconic acid as the acid component, and saturated acids such as phthalic anhydride, isophthalic acid, and adipic acid as necessary, and the alcohol component uses It can be obtained by condensation polymerization of these acid components and alcohol components using ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, glycerin, etc.

As the acid component and alcohol component, ester-forming derivatives thereof can be used.
Further, the unsaturated acid is used in an amount of about 20 to 40 mol % in the acid component. The unsaturated polyester preferably has an acid value of 10 to 50, and a molecular weight of about 1000 to 6000.

Styrene, vinyltoluene, vinyl acetate, ethyl acrylate, methyl methacrylate, divinylbenzene and the like are used as the polymerizable monomer of the present invention.

As the curing agent for unsaturated polyester resin, conventionally known curing agents can be used. For example, there are polymerization initiators such as benzoyl peroxide and methyl ethyl ketone peroxide. The curing agent is used in an amount of 0.1 to 5% by weight based on the unsaturated polyester resin. Further, a curing accelerator such as cobalt octenoate, cobalt naphthenate, dimethylaniline, etc. can be used together with the curing agent.

The foamed resin composite of the present invention can be obtained by applying an unsaturated polyester resin to the above-mentioned expanded styrene resin molding and curing it, or by immersing the expanded styrene resin foam in a predetermined unsaturated polyester resin, and then curing the unsaturated polyester resin. There are methods such as curing saturated polyester resin. In this case, it can be applied through a glass mat, glass cloth, etc., or the styrene resin foam can be covered with a glass mat, glass cloth, etc.

Next, examples of the present invention will be shown.

Example 1 [Manufacture of expanded styrene resin molded product] Ion-exchanged water was placed in an autoclave equipped with a rotating stirrer.
1,500 g of styrene monomer, 2.25 g of basic calcium phosphate, 0.045 g of sodium dodecylbenzenesulfonate, and 0.15 g of sodium sulfate were added, and then 7.5 g of γ-methacryloxypropyltrimethoxysilane was added as an organic silane compound to 1,500 g of styrene monomer. Next, 3.75 g of benzoyl peroxide and 1.5 g of tert-butyl perbenzoate were dissolved and heated to 90°C while stirring.
The temperature was raised to start polymerization. 1.5 g of basic calcium phosphate was added 3 hours after the start of polymerization, and the reaction was continued for an additional 5 hours. Next, 15 g of ethylbenzene was added, and 20 minutes later, 250 ml of butane gas was pressurized with nitrogen gas. After the butane gas injection was completed, the temperature started to rise again, and after 2 hours, the temperature was raised to 125°C, and the reaction was continued for 4 hours while maintaining this temperature. Afterwards, the system was cooled to 30°C and the excess gas in the system was discharged. Thereafter, the mixture was dried in an oven to obtain expandable styrene resin particles. The particles contain 8.5% by weight of butane as a blowing agent. These particles were sieved and obtained particles with a diameter of 1.68 to 0.84 mm were foamed using steam to a bulk ratio of 40 times to obtain pre-expanded particles. Furthermore, pre-expanded particles were added to 300mm x 300mm x
The mixture was filled into a mold with an internal space of 50 mm and steam-molded using a known method to obtain a foamed styrene resin molded article (molded product) having the above dimensions.

[Manufacture of unsaturated polyester resin]

1670g propylene glycol, maleic anhydride
980g, phthalic anhydride 1480g, hydroquinone 0.1
g into a flask equipped with a condenser, and heated to 80 to 90°C while gently passing carbon dioxide gas to uniformly melt the contents.Then, the temperature was raised to 150°C over 1 hour, and then to 190°C over 3 hours. Increase the temperature to. Keep it at 190℃ and adjust the temperature to 100~200℃ as needed.
The pressure was reduced to mm and continued until the acid value reached 50 or less. At the final stage of the reaction, 0.1 g of hydroquinone is added and cooled.
Add styrene monomer to 70 parts of the resulting unsaturated polyester
Add 30 parts of unsaturated polyester resin (resin)
And so.

[Manufacture of foamed resin composite]

Place the molded product on a table, place a glass mat on top of it, and add 1% methyl ethyl ketone peroxide and 6% cobalt naphthenate to the resin.
was applied, covered with polyester film, and cured. The polyester film was peeled off by inverting and performing the same operation to obtain an FRP sandwich board having a foam core. This FRP sanderch board structure has strength and heat insulation properties, and is also lightweight, so it is used in water tanks, boats, fishing vessels, etc.

Comparative Example 1 Expandable polystyrene particles HiBeads MB (trade name, Hitachi Chemical Co., Ltd.) were steam-molded by a known method to obtain a molded product (molded product) of 300 mm x 300 mm x 50 mm (50 times foamed product). An attempt was made to create an FRP sandwich board using resin on this molded product in the same manner as in Example 1, but the molded product melted and became uniform.
I was unable to create an FRP sandwich board.

Example 2 The pre-expanded particles of Example 1 were molded into a container shape, and while a glass cloth was attached to the inner surface of the container, a corrosion-resistant unsaturated polyester resin Polyset 660AP was formed.
A corrosion-resistant container was obtained by lining and hardening with peroxide catalyst CT-3.1%.

Example 3 Glass cloth, flame-retardant unsaturated polyester resin Polyset 730A (trade name of Hitachi Chemical Co., Ltd.) and accelerator PT were applied over the entire surface of the molded plate of Example 1.
Hand lay-up molding with a mixture of 28.0.5% catalyst CT-3.1% and has surface flame retardancy.
An FRP composite was obtained.

According to the present invention, a foamed resin composite that has excellent heat insulation properties and rigidity and is easy to manufacture can be manufactured using a foamed styrene resin molded body.

Claims (1)

[Scope of Claims] 1. A foamed resin composite formed by coating a part or the entire surface of a foamed styrene resin molded article with an unsaturated polyester resin cured product, wherein the foamed styrene resin molded article contains a styrene resin and a cured unsaturated polyester resin. A foamable styrenic resin composition containing a blowing agent, wherein the styrenic resin has the general formula () -SiYnR _3-o () in the molecule (where R is an inert monovalent organic group). ,Y
is a hydrolyzable group, and n is an integer of 1 to 3), and the foamable styrenic resin composition optionally contains at least two or more hydrolyzable groups. A foamed resin composite comprising a foam of a foamable styrenic resin composition containing an organic silane compound having the following properties. 2. The foamed resin composite according to claim 1, wherein the foamed resin composite is obtained by coating a part or the entire surface of a foamed styrene resin molding with an unsaturated polyester resin and then curing the resin.