JPH01249803A - Production of resin - Google Patents

Abstract

PURPOSE:To readily and inexpensively provide an internal strain-free resin, by polymerizing a liquid containing monomers, oligomers or a mixture thereof comprising a bisallylic compound and a (meth)acrylic compound as essential components while a specific liquid is placed on the liquid. CONSTITUTION:A polymerizable liquid A containing monomers, oligomers or a mixture thereof comprising a bisallylic compound and/or (meth)acrylic compound as essential components is polymerized, while a liquid B having a little solubility with the liquid A and a density smaller than that of the liquid A is placed on the liquid A. As the mixture in the liquid A, a mixture containing an aliphatic, alicyclic or aromatic dihydric alcohol bis(allyl carbonate) monomer of the formula (R is the residue of a dihydric alcohol; n or the average value of n is 1-10), an oligomer or a mixture thereof is preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing a resin, and more particularly to a method for producing a cured resin molding.

More specifically, bisallyl compounds and/or (
When polymerizing a polymerizable liquid material containing a monomer or oligomer containing a meth)acrylic compound as an essential component, or a mixture thereof, it is possible to obtain a molded product with less distortion and having similar hardness on the surface and inside. The present invention relates to a method for manufacturing a resin molded article.

<Prior art> When monomers and oligomers such as diethylene glycol bisallyl carbonate and methyl methacrylate are polymerized, especially when these materials are polymerized using various radical polymerization initiators, these materials are exposed to oxygen such as air. When it comes into contact with oxygen, the radicals necessary for polymerization are consumed by oxygen, making it impossible to obtain a high degree of polymerization.
It is not possible to obtain sufficient hardness.

Therefore, when such materials are polymerized, the polymerization reaction is usually allowed to proceed while blocking contact with air or the like using a mold or the like.

However, due to the shape of the object, if polymerization has to be carried out with part or the upper part of the mold open to the air, a sufficient degree of polymerization cannot be obtained on the surface in contact with the air. , it turns into a viscous liquid or gel.

Therefore, in such cases, polymerization is carried out by covering the surfaces of monomers, oligomers, etc. that come into contact with air with an inert gas such as nitrogen or argon.

However, such a polymerization method requires a large amount of energy and time to replace oxygen, resulting in high costs.

On the other hand, there is also a method in which the surface of monomers, oligomers, etc. is blocked with an elastic material and polymerized, but this method is difficult to use when the shape of the target resin is complex. During polymerization, stress is applied to the resin by elastic bodies, etc., and optical distortion occurs in the resin.
There are problems such as high costs and low productivity.

<Problems to be Solved by the Invention> The present invention solves the above-mentioned problems of the prior art and provides a polymerization method containing a monomer or oligomer containing a bisallyl compound and/or (meth)acrylic compound as an essential component, or a mixture thereof. In order to obtain a cured resin molded product by polymerizing a possible liquid material in a state open to the atmosphere,
To provide a method for producing a resin, which allows a molded product having the same hardness on the inside and surface of the resin and no optical distortion to be obtained through a simple process, and also allows molding of complex shapes. purpose.

Means for Solving the Problems> The present invention provides bisallyl compounds and/or (meth)
Dissolving a polymerizable liquid material containing the monomer or oligomer or a mixture thereof [A] on a polymerizable liquid material containing the monomer or oligomer or a mixture thereof [A] containing an acrylic compound as an essential component. The monomer, oligomer, or mixture thereof [A] is prepared by the presence of a liquid material [C] having a lower density than the density of the polymerizable liquid material containing the monomer or oligomer or the mixture thereof [A]. ]
Provided is a method for producing a resin, which comprises polymerizing a polymerizable liquid material containing:

Further, the monomer or oligomer or the mixture thereof [A] has the following formula (a) (a) (wherein R is a residue of a dihydric alcohol, and the value of n or the average value of n is 1 to 10. , preferably 2 to 10), or a mixture thereof.

Moreover, it is preferable that the liquid material [C] is a low molecular weight liquid synthetic hydrocarbon polymer, a liquid hydrocarbon mixture, or a mixture thereof.

In addition, in the present invention, the monomers, oligomers, or mixtures thereof that contain a bisallyl compound as an essential component refer to monomers or oligomers alone, oligomers alone, mixtures of monomers and oligomers, mixtures of two or more types of oligomers, and mixtures of two or more types of oligomers. Mixture or monomer or monomers
fff1 or more and one type of oligomer or a mixture of two or more types.

Further, in the present invention, the polymer may be a homopolymer or a copolymer. <Configuration of the Invention> The present invention will be described in detail below.

FIG. 1 shows a preferred embodiment of the resin manufacturing method of the present invention.

The method for producing the resin of the present invention includes monomers or oligomers containing bisallyl compounds and/or (meth)acrylic compounds as essential components, or mixtures thereof [A
] (hereinafter referred to as [A]).As shown in Figure 1, this [A]
On top of the polymerizable liquid material containing [A], a liquid material [C ]
polymerize in the presence of

[A] polymerized by the polymerization method (curing method) of the present invention is
It is a monomer or oligomer, or a mixture thereof, containing a bisallyl compound and/or a (meth)acrylic compound as an essential component.

The bisallyl compound used in [A] is not particularly limited as long as it is a bisallyl compound, and examples thereof include those described in JP-A-59-45312;
Copolymer composition of nuclear halogen-substituted benzenedicarboxylic acid with sialylene glycol diallyl carbonate [1],
One or more of the halogen-substituted benzenedicarboxylic acid esters (for example, 2,4-dichloroterephthalic acid bisallyl ester, etc.) described in JP-A-59-8709 and a refractive index of 1.55 as a homopolymer. A copolymerizable composition [
I+ ], one or more specific bisallyl carbonates or bisβ-methylallyl carbonates [e.g., 1,4-bis(hydroxyethoxy)benzenebisallyl carbonate, etc.] described in JP-A-59-8710, and alone 1f of a radically polymerizable, aromatic ring-containing monofunctional monomer (for example, phenyl methacrylate, etc.) that has a refractive index of 1.55 or more as a polymer! A copolymerizable composition with the above [III, described in JP-A-59-96109, a monool (e.g. 4-benzyl-phenol) and an unsaturated carboxylic acid (chloride) [e.g. acrylic acid (chloride)]. A copolymerizable composition [IV] of a monomer reacted with a radically polymerizable monomer (e.g. styrene) whose homopolymer has a refractive index of 1.55 or more, described in JP-A-59-96113. A copolymerizable composition of an allyl ester of chlorobenzoic acid (for example, diallyl ester of 2,3-dichlorobenzoic acid) and a difunctional monomer (for example, diallyl ester of tetrabromophthalic acid) [
V], copolymerizable composition described in JP-A-59-184210 [V+], diethylene glycol bisallyl carbonate [■],
and an aliphatic, alicyclic or aromatic group represented by the general formula (wherein R is the residue of a dihydric alcohol, and the value of n or the average value of n is 1 to 1o1, preferably 2 to 10) A composition [■] containing a dihydric alcohol bis(allyl carbonate) monomer or oligomer or a mixture thereof (a) is listed! be pulled. In the case of [■], component (a) is preferably a reaction product of diallyl carbonate and dihydric alcohol in a molar ratio of 4:1 or less, more preferably 2:1. The dihydric alcohol is preferably ethylene glycol,
1.3-propanediol, 1,4-butanediol,
1,6-hexanediol, diethylene glycol, polyethylene glycol, dipropylene glycol, propylene glycol, neopentyl glycol, trimethylbentanediol, cyclohexane dimetatool, bis(hydroxymethyl)tricyclodecane, 2,7-norbornanediol, α, a′-xylene diol,
1.4-bis(hydroxyethoxybenzene) and 2
．． It is preferable to use one or more types of 2-bis(4-(hydroxyethoxy)phenyl)propane.

In addition, in the present invention, such bisallyl compounds include the following components (a'), (b) and (
The liquid composition [■'] of bis(allyl carbonate) containing e) is more preferably used, and is disclosed in JP-A-59-140
The description of Publication No. 214 is incorporated herein by reference.

Component (a') is an aliphatic, alicyclic or alicyclic compound represented by the general formula: Oligomers or oligomer mixtures of the aromatic dihydric alcohol bis(allyl carbonate) (
However, in the above formula, the bis(allyl carbonate) monomer of the dihydric alcohol optionally contained in the oligomer is 50% by weight or less) 10 to 90% by weight, and component (b) is represented by the general formula (formula where R' is a residue of a dihydric or trihydric alcohol, and n' is 2 or 3). (allyl carbonate) monomer or mixture (optional bis(allyl carbonate) oligomer or poly(allyl carbonate) of dihydric or trihydric alcohol contained in said monomer or mixture is not more than 30% by weight), General formula (wherein R'' is a residue of dicarboxylic acid or tricarboxylic acid, n'' is 2 or 3
0 to 90% by weight of a compound selected from allyl esters of aliphatic or aromatic dicarboxylic acids or tricarboxylic acids represented by The total amount of compounds (b) and (C) is greater than 0.

Component (a') is preferably the product of the reaction of diallyl carbonate and dihydric alcohol in a molar ratio of 4:1 or less, preferably 2:1, where the dihydric alcohol is ethylene glycol, 1,3-propane. Diol, 1.4
-Butanediol, 1,6-hexanediol, diethylene glycol, polyethylene glycol, dipropylene glycol, propylene glycol, neopentyl glycol, trimethylbentanediol, cyclohexane dimetatool, bis(hydroxymethyl)tricyclodecane, 2,7-norbornane Preferably, it is selected from diols, α, α'-xylene diol, 1,4-bis(hydroxyethoxybenzene), and 2°2-bis(4-(hydroxyethoxy)phenyl)propane.

Component (b) is a molar ratio of diallyl carbonate to dihydric or trihydric alcohol of 6.1 or more, preferably 12:1.
Preferably, the dihydric or trihydric alcohol is ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1°6-hexanediol, diethylene glycol, polyethylene glycol, dipropylene glycol. , propylene glycol, neopendel glycol, trimethylbentanediol, cyclohexane dimetatool, bis(hydroxymethyl)tricyclodecane, 2,7-norbornanediol, α,α′-xylene diol, 1,4-bis(hydroxyethoxybenzene) ), 2.2-bis(4-(hydroxyethoxy)phenyl)propane, trimethylolpropane, and tri(hydroxyethyl) isocyanurate, or 2 fffi or more.

Component (b) may also be diallyl phthalate, diallyl succinate, diallyl adipate, diallyl carbonate, diallylglycolate-1., diallylnaphthalene dicarboxylate, and triallylmeridate.

Preferably, component (C) is one or more of vinyl acetate, vinyl benzoate, methyl methacrylate, phenyl methacrylate, methyl acrylate, methyl maleate, maleic anhydride, and vinylidene chloride.

The polymerizable liquid containing [A] preferably includes bisallyl such as diethylene glycol bisallyl carbonate, 1.4 bis(hydroxyethoxy)benzene bisallyl carbonate, and 2,4-dichloroterephthalic acid bisallyl ester. Copolymerizable compositions of a compound and a vinyl monomer having an aromatic ring such as phenyl methacrylate and benzyl methacrylate can be mentioned.

The (meth)acrylic compound used in [A] is not particularly limited, but mono(meth)acrylates and di(meth)acrylates represented by the following structural formulas are preferably used, but in particular di(meth)acrylates are preferably used. (Meth)acrylate is preferred.

CH2=CHC0-(OCH2CH2). 0CH3n
=3~9 CH2=CH-C○0CH2CH20COCH2CH2
-COOHCH2=CHC0(OCH3CH2)2 0
(CH2)3 CH3CH3 CH2=Cco (OCH2CH2)n 0CH3n
=2-23 H3 CH2=CC00CHs n=1-23 n Cape 9 CH2=CHCo-0(CH2-C)120). Co
-CH=CH2n=4~14 CH2=CH-COO-(CH2)a 0OC-CH=
CH2n=1-9 Such a polymerizable liquid material containing [A] may contain various polymerization initiators.

In the present invention, when polymerizing the polymerizable liquid material containing [A], there are no particular restrictions on the polymerization initiator used as long as it does not adversely affect the transparency, color, or other properties of the resin to be formed. However, any initiator such as a photopolymerization initiator, a thermal polymerization initiator, a photo/thermal polymerization initiator, etc. may be used.

In addition to photopolymerization initiators, photopolymerization initiators include electron beam and radiation polymerization initiators.

Examples of the photopolymerization initiator include 2-hydroxy-2-methyl-1-phenyl-propan-1-one.

As a thermal polymerization initiator, peroxydicarbonates such as diisopropyl peroxydicarbonate, di-secandabutyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, and tertiary butyl perbenzoate;
benzoyl peroxide, acetyl peroxide, t-
Butyl hydroperoxide, cumene hydroperoxide, di-t-butyl peroxide, peroxybenzoic acid
Organic A oxides such as t-butyl, lauroyl peroxide, diisopropyl peroxydicarbonate, methyl ethyl ketone peroxide, diacyl peroxides, inorganic peroxides, and radical initiation such as azobisisobutyronitrile, azobismethylisovaleronitrile, etc. Examples include agents.

Examples of the photo/thermal polymerization initiator include the following compounds.

The amount of the polymerization initiator used is 0.1 to 10 wt%, preferably 1 to 6 wt%, based on the polymerizable liquid material containing [A].
%.

Further, other monomers and other fillers can be added to the polymerizable liquid material containing the polymerizable liquid material containing [A] to the extent that the physical properties of the resulting polymer are not impaired.

For example, it is also possible to add unsaturated carboxylic acids such as maleic anhydride or silane coupling agents such as vinyltriethoxysilane in proportions of up to 10% by weight.

The density of the polymerizable liquid material containing [A] is not particularly limited, but is usually about 0.9 to 1.2 g/m''.

In addition, as such a polymerizable liquid material containing [A], a prepolymer obtained by prepolymerizing the above-mentioned material using a polymerization initiator or the like to the extent that fluidity is maintained can also be suitably used.

In the polymerization method of the present invention, in addition to the polymerizable liquid material containing [A], as shown in FIG.
Containing [A] in the presence of a liquid substance [C] that has low solubility with the polymerizable liquid substance containing [A] and has a density lower than the density of the polymerizable liquid substance containing [,A] The polymerizable liquid is preferably polymerized in the presence of a polymerization initiator.

There are no particular restrictions on the liquid substance [C] as long as it has low solubility with the polymerizable liquid substance containing [A] and has a density lower than that of the polymerizable liquid substance containing [A]. do not have.

In this case, the solubility in the polymerizable liquid material [C] containing [A] is so small that it does not adversely affect the transparency, weather resistance, surface properties, surface hardness, etc. of the resin to be formed. For example, when expressed in terms of solubility, it is usually 5% or less, preferably 2% or less.

When the solubility is like this, a preferable result is obtained in that the surface and interior of the resulting resin have similar hardness (degree of polymerization).

In addition, the density of the liquid [C] is not particularly limited, but it is usually 1
Below, it is preferably about 0.8 to 0.95.

Such liquid material [C] is preferably a low molecular weight liquid synthetic hydrocarbon polymer, a liquid hydrocarbon mixture, or a mixture thereof.

Examples of synthetic hydrocarbon polymers include poly(α-olefin) oil such as polydecene-1, alkyl aromatic oil such as alkylbenzene, polybutene oil (liquid polybutene), polyhexene, and 2,4-dicyclohexyl-2-methylpentane. Alkylnaphthene oils such as oil, and ethylene/α-olefin random copolymer extracted oils such as ethylene-propylene random copolymer oils are used.

Among these, those with a molecular weight of 500 or more, preferably 100
0 to 10,000 is preferred.

Further, ethylene and α-olefin random copolymer oil having a number average molecular weight (Mn) of 500 to 5,000, particularly 1,500 to 3,000 are also preferred.

It also consists of 30 to 70 mol% of ethylene component units and 30 to 70 mol% of α-olefin component units, has a number average molecular weight (Mn) in the range of 1000 to 5000, and has a Q value (weight average molecular weight/number average molecular weight). A liquid low molecular weight ethylene/α-olefin copolymer having a molecular weight of 3 or less is particularly preferred. When a liquid polyolefin or the like is used as the liquid material [C], the liquid material itself also exhibits a mold release effect, making mold release extremely easy. After polymerization, the liquid polyolefin can be easily removed with an organic solvent such as hexane, kerosene, or trichlene.

Moreover, water is also suitably used as the liquid substance [C].
Water has a high vapor pressure and is therefore suitable for polymerization at relatively low temperatures.

Alternatively, polymerization may be carried out by covering the surface of the liquid material [C] with an inert gas atmosphere having an oxygen concentration of 1% or less. In such a case, more favorable results can be obtained in that a resin with high surface hardness can be obtained. obtain.

In the polymerization method of the present invention, a polymerizable liquid material containing [A] that has low solubility with the polymerizable liquid material containing [A] is added to the polymerizable liquid material containing [A]. This is a polymerization method in which polymerization is carried out in the presence of a liquid material [C] having a density lower than that of .

Although any method may be used to make the liquid material [C] exist on the polymerizable liquid material containing [A], the following method is exemplified as a preferable example.

A polymerizable liquid material containing the above-mentioned [A] containing a polymerization initiator is poured into a mold 10 with an open top. and,
At the upper interface (surface) of the polymerizable liquid material containing [A],
Furthermore, liquid substance [C] is injected to cut off contact between the polymerizable liquid substance containing [A] and air (oxygen).

As shown in FIG. 1, 'Pt
Polymerizable liquid material containing [A] - [A polymerizable liquid material containing [A] is polymerized in a system consisting of a C12 layer.

It is preferable to add each liquid in descending order of density as described above, but be careful to prevent suspension between the liquids.
After first injecting the liquid [C] into the mold 10, [A]
A layer of liquid [C] may be formed on the layer of polymerizable liquid containing [A] by injecting a polymerizable liquid containing [A].

As the mold 10 used in the polymerization method of the present invention, any commonly used mold such as glass, polyvinyl chloride, polyethylene resin, polypropylene resin, poly4-methyl-1-pentene resin, etc. can be used.

Further, the shape of the mold 10 may be appropriately selected depending on the shape of the object to be formed.

Polymerization can be carried out under various conditions depending on the composition of the polymerizable liquid material containing [A] and the polymerization initiator contained.

In thermal polymerization, it varies depending on the shape and size, but for example, it is placed in a heating tank and heated to 30 to 150°C, preferably 40 to 120°C.
C. for 0.5 to 72 hours, preferably 1 to 4 hours.

In photopolymerization, for example, 60 W/cm to 150 W/cm
under a high-pressure mercury lamp for 1 to 2 hours, preferably 3 to 30 minutes,
The polymerization is preferably carried out at a temperature of 40 to 120°C, preferably 60 to 100°C.

The cured resin molded product obtained by the polymerization method of the present invention has virtually no difference in hardness between the surface and the inside, and has no internal optical distortion, so it can be used as an optical lens, transparent plate, rod-shaped transparent body, etc. Can be widely used.

<Example> The present invention will be specifically explained below using Examples.

(Example 1) 25.8 g of the following polymerizable liquid containing [A] was poured into a beaker with an inner diameter of 5 cm.

Polymerizable liquid material containing [A]-1 Diallyl carbonate and diethylene glycol were mixed in a molar ratio of 2:1 in the presence of sodium ethoxide in JP-A No. 5
6-133246 (30 wt% is diethylene glycol bisallyl carbonate, 70 wt% is oligocarbonate, n
;3-10) ...55% by weight
Tris(hydroxyethyl) isocyanurate prepared by reacting diallyl carbonate and tris(hydroxyethyl) isocyanurate at a molar ratio of 12:1
Tris (allyl carbonate)...
・12.4% by weight diethylene glycol bisallyl carbonate
・・・ ・・・ 2
7, 5 coi amount % vinyl acetate
...5% by weight diisopropyl peroxydicarbonate ...2.5% by weight On top of the polymerizable liquid material-1 containing this [A], as a liquid material [C], the density 0.846 ethylene propylene copolymer (M n 2500, Q value 2.0) with a layer thickness of 1
Injected up to cm.

The beaker containing the two layers thus obtained was placed in an air oven and the temperature was raised stepwise from 40°C to 85°C over 5 hours to polymerize the polymerizable liquid material-1 containing [A]. was terminated.

The surface of the obtained resin has a pencil hardness and a 3H1 density of 1.3.
31 and was sufficiently cured.

Further, when observed with a polariscope, optical distortion was extremely small. Furthermore, when the surface roughness was measured using a surface roughness meter (manufactured by Mitoyo Seisakusho), the measurement length was 0.75 mm, and R
, 0,002 μm, R□) 10.03 μm, and the surface smoothness was also good.

(Example 2) Polymerization of polymerizable liquid material-1 containing [A] was completed in the same manner as in Example 1 except that the layer thickness of liquid material [C] of Example 1 was changed to 0.2 cm. .

The surface of the obtained resin has a pencil hardness of 3H and a density of 1.3.
It was sufficiently cured at 30.

Further, when observed with a ballariscope, optical distortion was extremely small. Furthermore, when the surface roughness was measured using a surface roughness meter (manufactured by Mitoyo Seisakusho), the measurement length was 0.75 mm, and R
, 0,003 μm, R□, 0.05 μm, and the surface smoothness was also good.

(Example 3) The following polymerizable liquid material containing [A] was poured into a beaker with an inner diameter of 5 cm to a layer thickness of 0.8 cm.

Polymerizable liquid material containing [A]-2 Prepared by reacting diallyl carbonate and diethylene glycol at a molar ratio of 2:1 in the presence of sodium ethoxide under the conditions described in JP-A-56-133246. (3rd layer wt% is diethylene glycol, bisallyl carbonate, 70 wt% is oligocarbonate, n = 3 to 7) 58 wt% diallyl carbonate and tris(hydroxyethyl isocyanurate) at a molar ratio of 12 : Tris(allyl carbonate) of tris(hydroxyethyl) isocyanurate prepared by reacting in 1.
...13% by weight diethylene glycol bisallyl carbonate ...29
Weight% diisopropyl peroxydicarbonate...
...2.7% by weight Further, as the liquid [C], an ethylene propylene copolymer with a density of 0.846 (Mn250
0, Q value 2.0) was injected to a layer thickness Q of 5 cm.

The beaker containing the two layers thus obtained was placed in an air oven and the temperature was raised stepwise from 40°C to 85°C over 5 hours to polymerize the polymerizable liquid material-2 containing [A]. was terminated.

The surface of the obtained resin has a pencil hardness 3H1 density of 1.34.
It was sufficiently cured at 0.

Further, when observed with a ballariscope, optical distortion was extremely small. Furthermore, when the surface roughness was measured using a surface roughness meter (manufactured by Mitoyo Seisakusho), the measurement length was 12.5 mm, and R
, 0.03 μm1R1□0.3 μm, and the surface smoothness was also good.

(Example 4) Into a 50 ml beaker with an inner diameter of 5 cm, the following polymerizable liquid containing [A] was poured to a layer thickness of 0.8 cm.

Polymerizable liquid material containing [A]-3 A monomer with a viscosity of 14 cps/25°C, a saponification value of 340, and a bromination of 93...99.5 Benzoyl peroxide... ...0.5% by weight The density of this product was 1.08 g/am3.

The beaker containing the three layers thus obtained was placed in an air oven and heated at 88° C. for 6 hours and at 100° C. for 2 hours.

The obtained resin had a pencil hardness of 3H on both the upper and lower surfaces and a density of 1.2250.

Further, when observed with a ballariscope, optical distortion was extremely small. Furthermore, the surface smoothness was also good.

From the above results, the effects of the present invention are clear.

<Effects of the Invention> According to the method for producing a resin of the present invention, a monomer or oligomer or a mixture thereof containing a bisallyl compound and/or (meth)acrylic compound as an essential component is produced using a partially open mold. When obtaining a cured resin molded product by polymerization, a molded product with high surface hardness can be obtained through a simple process and at low cost.

Moreover, since the surface of the monomer, oligomer, or mixture thereof is shielded from air (oxygen) by a predetermined liquid material, it is possible to easily mold products with complex shapes, and furthermore, during polymerization, It is also possible to follow the shrinkage of the volume of the air, ensuring reliable shielding from air.

Furthermore, since stress is not applied to the monomer or oligomer during polymerization compared to an elastic body such as a mold, a molded product without distortion can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of the polymerization method of the present invention. Explanation of symbols 10...Mold FIG, 1

Claims (3)

[Claims] (1) On top of a polymerizable liquid containing a monomer or oligomer containing a bisallyl compound and/or a (meth)acrylic compound as an essential component, or a mixture thereof [A], the monomer or oligomer or a mixture thereof [A] is added. Presence of a liquid material [C] that has low solubility with the polymerizable liquid material containing A] and has a density lower than that of the polymerizable liquid material containing the monomer or oligomer or a mixture thereof [A]. A method for producing a resin, comprising: polymerizing a polymerizable liquid material containing the monomer, oligomer, or mixture thereof [A]. (2) The monomer, oligomer, or mixture thereof [A] has the following formula (a) Formula (a) ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R is a residue of dihydric alcohol, or the average value of n is from 1 to 10, preferably from 2 to 10), or a mixture thereof. The method for producing a resin according to claim 1, which comprises: (3) The method for producing a resin according to claim 1 or 2, wherein the liquid material [C] is a low molecular weight liquid synthetic hydrocarbon polymer, a liquid hydrocarbon mixture, or a mixture thereof.